data_type large_stringclasses 3
values | source large_stringclasses 29
values | code large_stringlengths 98 49.4M | filepath large_stringlengths 5 161 ⌀ | message large_stringclasses 234
values | commit large_stringclasses 234
values | subject large_stringclasses 418
values | critique large_stringlengths 101 1.26M ⌀ | metadata dict |
|---|---|---|---|---|---|---|---|---|
lkml_critique | lkml | From: Jan Kiszka <jan.kiszka@siemens.com>
This resolves the follow splat and lock-up when running with PREEMPT_RT
enabled on Hyper-V:
[ 415.140818] BUG: scheduling while atomic: stress-ng-iomix/1048/0x00000002
[ 415.140822] INFO: lockdep is turned off.
[ 415.140823] Modules linked in: intel_rapl_msr intel_rapl_com... | null | null | null | [PATCH] scsi: storvsc: Fix scheduling while atomic on PREEMPT_RT | Hi Jan,
It's interesting to know the use-case of running a RT kernel over Hyper-V.
Can you give an example?
As far as I know, Hyper-V makes no RT guarantees of scheduling VPs for a VM.
Thanks,
Long | {
"author": "Long Li <longli@microsoft.com>",
"date": "Mon, 2 Feb 2026 23:47:31 +0000",
"is_openbsd": false,
"thread_id": "898e9467-0c05-46b4-a3ed-518797b829c5@siemens.com.mbox.gz"
} |
lkml_critique | lkml | From: Jan Kiszka <jan.kiszka@siemens.com>
This resolves the follow splat and lock-up when running with PREEMPT_RT
enabled on Hyper-V:
[ 415.140818] BUG: scheduling while atomic: stress-ng-iomix/1048/0x00000002
[ 415.140822] INFO: lockdep is turned off.
[ 415.140823] Modules linked in: intel_rapl_msr intel_rapl_com... | null | null | null | [PATCH] scsi: storvsc: Fix scheduling while atomic on PREEMPT_RT | On 03.02.26 00:47, Long Li wrote:
- functional testing of an RT base image over Hyper-V
- re-use of a common RT base image, without exploiting RT properties
This is well understood and not our goal. We only need the kernel to run
correctly over Hyper-V with PREEMPT-RT enabled, and that is not the case
right now.
Th... | {
"author": "Jan Kiszka <jan.kiszka@siemens.com>",
"date": "Tue, 3 Feb 2026 06:57:46 +0100",
"is_openbsd": false,
"thread_id": "898e9467-0c05-46b4-a3ed-518797b829c5@siemens.com.mbox.gz"
} |
lkml_critique | lkml | From: Jan Kiszka <jan.kiszka@siemens.com>
This resolves the follow splat and lock-up when running with PREEMPT_RT
enabled on Hyper-V:
[ 415.140818] BUG: scheduling while atomic: stress-ng-iomix/1048/0x00000002
[ 415.140822] INFO: lockdep is turned off.
[ 415.140823] Modules linked in: intel_rapl_msr intel_rapl_com... | null | null | null | [PATCH] scsi: storvsc: Fix scheduling while atomic on PREEMPT_RT | On 03.02.26 06:57, Jan Kiszka wrote:
OK, after some guessing, the patched kernel boots again. So I think I
also fixed the broken vmbus IRQ patch by threading it under RT.
Currently building a kernel inside the VM while lockdep is enabled.
Boot-up and first minutes of building didn't trigger any complaints.
Will share ... | {
"author": "Jan Kiszka <jan.kiszka@siemens.com>",
"date": "Tue, 3 Feb 2026 07:10:19 +0100",
"is_openbsd": false,
"thread_id": "898e9467-0c05-46b4-a3ed-518797b829c5@siemens.com.mbox.gz"
} |
lkml_critique | lkml | From: Jan Kiszka <jan.kiszka@siemens.com>
This resolves the follow splat and lock-up when running with PREEMPT_RT
enabled on Hyper-V:
[ 415.140818] BUG: scheduling while atomic: stress-ng-iomix/1048/0x00000002
[ 415.140822] INFO: lockdep is turned off.
[ 415.140823] Modules linked in: intel_rapl_msr intel_rapl_com... | null | null | null | [PATCH] scsi: storvsc: Fix scheduling while atomic on PREEMPT_RT | From: Jan Kiszka <jan.kiszka@siemens.com> Sent: Monday, February 2, 2026 9:58 PM
Hmmm. I often do printk()-based debugging via a virtual UART in a Gen 2
VM. The Linux serial console outputs to that virtual UART and I see the
printk() output in PuTTY on the Windows host. What specifically are you
trying to do? I'm try... | {
"author": "Michael Kelley <mhklinux@outlook.com>",
"date": "Thu, 5 Feb 2026 05:42:02 +0000",
"is_openbsd": false,
"thread_id": "898e9467-0c05-46b4-a3ed-518797b829c5@siemens.com.mbox.gz"
} |
lkml_critique | lkml | From: Jan Kiszka <jan.kiszka@siemens.com>
This resolves the follow splat and lock-up when running with PREEMPT_RT
enabled on Hyper-V:
[ 415.140818] BUG: scheduling while atomic: stress-ng-iomix/1048/0x00000002
[ 415.140822] INFO: lockdep is turned off.
[ 415.140823] Modules linked in: intel_rapl_msr intel_rapl_com... | null | null | null | [PATCH] scsi: storvsc: Fix scheduling while atomic on PREEMPT_RT | On 05.02.26 06:42, Michael Kelley wrote:
Indeed:
Powershell> Set-VMComPort -VMName "Debian 13" 1 \\.\pipe\comport
<Start VM>
Powershell> putty -serial \\.\pipe\comport
Well hidden...
Jan
--
Siemens AG, Foundational Technologies
Linux Expert Center | {
"author": "Jan Kiszka <jan.kiszka@siemens.com>",
"date": "Thu, 5 Feb 2026 07:37:35 +0100",
"is_openbsd": false,
"thread_id": "898e9467-0c05-46b4-a3ed-518797b829c5@siemens.com.mbox.gz"
} |
lkml_critique | lkml | From: Jan Kiszka <jan.kiszka@siemens.com>
This resolves the follow splat and lock-up when running with PREEMPT_RT
enabled on Hyper-V:
[ 415.140818] BUG: scheduling while atomic: stress-ng-iomix/1048/0x00000002
[ 415.140822] INFO: lockdep is turned off.
[ 415.140823] Modules linked in: intel_rapl_msr intel_rapl_com... | null | null | null | [PATCH] scsi: storvsc: Fix scheduling while atomic on PREEMPT_RT | On Thu, 2026-01-29 at 15:30 +0100, Jan Kiszka wrote:
Tested-by: Florian Bezdeka <florian.bezdeka@siemens.com>
This patch survived a 24h stress test with CONFIG_PREEMPT_RT enabled and
heavy load applied to the system.
Without this patch - and very same system configuration - the system
will lock up within 2... | {
"author": "\"Bezdeka, Florian\" <florian.bezdeka@siemens.com>",
"date": "Thu, 5 Feb 2026 14:09:51 +0000",
"is_openbsd": false,
"thread_id": "898e9467-0c05-46b4-a3ed-518797b829c5@siemens.com.mbox.gz"
} |
lkml_critique | lkml | From: Jan Kiszka <jan.kiszka@siemens.com>
This resolves the follow splat and lock-up when running with PREEMPT_RT
enabled on Hyper-V:
[ 415.140818] BUG: scheduling while atomic: stress-ng-iomix/1048/0x00000002
[ 415.140822] INFO: lockdep is turned off.
[ 415.140823] Modules linked in: intel_rapl_msr intel_rapl_com... | null | null | null | [PATCH] scsi: storvsc: Fix scheduling while atomic on PREEMPT_RT | From: Jan Kiszka <jan.kiszka@siemens.com> Sent: Wednesday, February 4, 2026 10:38 PM
I just realized that the Hyper-V "Settings" UI for a VM shows COM1 and COM2
only for Gen1 VMs. I don't know why it's not shown for Gen2 VMs. The
Powershell command you found is what I have always used.
Michael | {
"author": "Michael Kelley <mhklinux@outlook.com>",
"date": "Thu, 5 Feb 2026 19:09:01 +0000",
"is_openbsd": false,
"thread_id": "898e9467-0c05-46b4-a3ed-518797b829c5@siemens.com.mbox.gz"
} |
lkml_critique | lkml | From: Jan Kiszka <jan.kiszka@siemens.com>
This resolves the follow splat and lock-up when running with PREEMPT_RT
enabled on Hyper-V:
[ 415.140818] BUG: scheduling while atomic: stress-ng-iomix/1048/0x00000002
[ 415.140822] INFO: lockdep is turned off.
[ 415.140823] Modules linked in: intel_rapl_msr intel_rapl_com... | null | null | null | [PATCH] scsi: storvsc: Fix scheduling while atomic on PREEMPT_RT | From: Jan Kiszka <jan.kiszka@siemens.com> Sent: Thursday, January 29, 2026 6:31 AM
Reviewed-by: Michael Kelley <mhklinux@outlook.com>
Tested-by: Michael Kelley <mhklinux@outlook.com> | {
"author": "Michael Kelley <mhklinux@outlook.com>",
"date": "Tue, 17 Feb 2026 15:47:19 +0000",
"is_openbsd": false,
"thread_id": "898e9467-0c05-46b4-a3ed-518797b829c5@siemens.com.mbox.gz"
} |
lkml_critique | lkml | From: Jan Kiszka <jan.kiszka@siemens.com>
This resolves the follow splat and lock-up when running with PREEMPT_RT
enabled on Hyper-V:
[ 415.140818] BUG: scheduling while atomic: stress-ng-iomix/1048/0x00000002
[ 415.140822] INFO: lockdep is turned off.
[ 415.140823] Modules linked in: intel_rapl_msr intel_rapl_com... | null | null | null | [PATCH] scsi: storvsc: Fix scheduling while atomic on PREEMPT_RT | On Thu, 29 Jan 2026 15:30:39 +0100, Jan Kiszka wrote:
Applied to 7.0/scsi-fixes, thanks!
[1/1] scsi: storvsc: Fix scheduling while atomic on PREEMPT_RT
https://git.kernel.org/mkp/scsi/c/57297736c082
--
Martin K. Petersen | {
"author": "\"Martin K. Petersen\" <martin.petersen@oracle.com>",
"date": "Tue, 24 Feb 2026 11:47:42 -0500",
"is_openbsd": false,
"thread_id": "898e9467-0c05-46b4-a3ed-518797b829c5@siemens.com.mbox.gz"
} |
lkml_critique | lkml | From: Jan Kiszka <jan.kiszka@siemens.com>
This resolves the follow splat and lock-up when running with PREEMPT_RT
enabled on Hyper-V:
[ 415.140818] BUG: scheduling while atomic: stress-ng-iomix/1048/0x00000002
[ 415.140822] INFO: lockdep is turned off.
[ 415.140823] Modules linked in: intel_rapl_msr intel_rapl_com... | null | null | null | [PATCH] scsi: storvsc: Fix scheduling while atomic on PREEMPT_RT | On 24.02.26 17:47, Martin K. Petersen wrote:
Should it be here then already?
https://git.kernel.org/pub/scm/linux/kernel/git/mkp/scsi.git/log/?h=7.0/scsi-fixes
Sorry, just trying to understand the process.
Jan
--
Siemens AG, Foundational Technologies
Linux Expert Center | {
"author": "Jan Kiszka <jan.kiszka@siemens.com>",
"date": "Fri, 27 Feb 2026 16:55:07 +0100",
"is_openbsd": false,
"thread_id": "898e9467-0c05-46b4-a3ed-518797b829c5@siemens.com.mbox.gz"
} |
lkml_critique | lkml | From: Xianwei Zhao <xianwei.zhao@amlogic.com>
Add Amlogic DMA controller entry to MAINTAINERS to clarify
the maintainers.
Signed-off-by: Xianwei Zhao <xianwei.zhao@amlogic.com>
---
MAINTAINERS | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/MAINTAINERS b/MAINTAINERS
index 5b11839cba9d..9b471d580b32 100644... | null | null | null | [PATCH v3 3/3] MAINTAINERS: Add an entry for Amlogic DMA driver | Add DMA driver and bindigns for the Amlogic SoCs.
Signed-off-by: Xianwei Zhao <xianwei.zhao@amlogic.com>
---
Changes in v3:
- Adjust the format of binding according to Frank's suggestion.
- Some code format modified according to Frank's suggestion.
- Support one prep_sg and one submit, drop multi prep_sg and one submi... | {
"author": "Xianwei Zhao via B4 Relay <devnull+xianwei.zhao.amlogic.com@kernel.org>",
"date": "Fri, 06 Feb 2026 09:02:31 +0000",
"is_openbsd": false,
"thread_id": "20260206-amlogic-dma-v3-0-56fb9f59ed22@amlogic.com.mbox.gz"
} |
lkml_critique | lkml | From: Xianwei Zhao <xianwei.zhao@amlogic.com>
Add Amlogic DMA controller entry to MAINTAINERS to clarify
the maintainers.
Signed-off-by: Xianwei Zhao <xianwei.zhao@amlogic.com>
---
MAINTAINERS | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/MAINTAINERS b/MAINTAINERS
index 5b11839cba9d..9b471d580b32 100644... | null | null | null | [PATCH v3 3/3] MAINTAINERS: Add an entry for Amlogic DMA driver | From: Xianwei Zhao <xianwei.zhao@amlogic.com>
Add documentation describing the Amlogic A9 SoC DMA.
Signed-off-by: Xianwei Zhao <xianwei.zhao@amlogic.com>
---
.../devicetree/bindings/dma/amlogic,a9-dma.yaml | 66 ++++++++++++++++++++++
1 file changed, 66 insertions(+)
diff --git a/Documentation/devicetree/binding... | {
"author": "Xianwei Zhao via B4 Relay <devnull+xianwei.zhao.amlogic.com@kernel.org>",
"date": "Fri, 06 Feb 2026 09:02:32 +0000",
"is_openbsd": false,
"thread_id": "20260206-amlogic-dma-v3-0-56fb9f59ed22@amlogic.com.mbox.gz"
} |
lkml_critique | lkml | From: Xianwei Zhao <xianwei.zhao@amlogic.com>
Add Amlogic DMA controller entry to MAINTAINERS to clarify
the maintainers.
Signed-off-by: Xianwei Zhao <xianwei.zhao@amlogic.com>
---
MAINTAINERS | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/MAINTAINERS b/MAINTAINERS
index 5b11839cba9d..9b471d580b32 100644... | null | null | null | [PATCH v3 3/3] MAINTAINERS: Add an entry for Amlogic DMA driver | From: Xianwei Zhao <xianwei.zhao@amlogic.com>
Amlogic A9 SoCs include a general-purpose DMA controller that can be used
by multiple peripherals, such as I2C PIO and I3C. Each peripheral group
is associated with a dedicated DMA channel in hardware.
Signed-off-by: Xianwei Zhao <xianwei.zhao@amlogic.com>
---
drivers/dm... | {
"author": "Xianwei Zhao via B4 Relay <devnull+xianwei.zhao.amlogic.com@kernel.org>",
"date": "Fri, 06 Feb 2026 09:02:33 +0000",
"is_openbsd": false,
"thread_id": "20260206-amlogic-dma-v3-0-56fb9f59ed22@amlogic.com.mbox.gz"
} |
lkml_critique | lkml | From: Xianwei Zhao <xianwei.zhao@amlogic.com>
Add Amlogic DMA controller entry to MAINTAINERS to clarify
the maintainers.
Signed-off-by: Xianwei Zhao <xianwei.zhao@amlogic.com>
---
MAINTAINERS | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/MAINTAINERS b/MAINTAINERS
index 5b11839cba9d..9b471d580b32 100644... | null | null | null | [PATCH v3 3/3] MAINTAINERS: Add an entry for Amlogic DMA driver | Hi Xianwei,
kernel test robot noticed the following build warnings:
[auto build test WARNING on 3c8a86ed002ab8fb287ee4ec92f0fd6ac5b291d2]
url: https://github.com/intel-lab-lkp/linux/commits/Xianwei-Zhao-via-B4-Relay/dt-bindings-dma-Add-Amlogic-A9-SoC-DMA/20260206-170903
base: 3c8a86ed002ab8fb287ee4ec92f0fd6ac5b... | {
"author": "kernel test robot <lkp@intel.com>",
"date": "Sat, 7 Feb 2026 03:08:01 +0800",
"is_openbsd": false,
"thread_id": "20260206-amlogic-dma-v3-0-56fb9f59ed22@amlogic.com.mbox.gz"
} |
lkml_critique | lkml | From: Xianwei Zhao <xianwei.zhao@amlogic.com>
Add Amlogic DMA controller entry to MAINTAINERS to clarify
the maintainers.
Signed-off-by: Xianwei Zhao <xianwei.zhao@amlogic.com>
---
MAINTAINERS | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/MAINTAINERS b/MAINTAINERS
index 5b11839cba9d..9b471d580b32 100644... | null | null | null | [PATCH v3 3/3] MAINTAINERS: Add an entry for Amlogic DMA driver | On Fri, Feb 06, 2026 at 09:02:32AM +0000, Xianwei Zhao wrote:
Needn't it, which is standard proptery.
Frank | {
"author": "Frank Li <Frank.li@nxp.com>",
"date": "Fri, 6 Feb 2026 14:33:42 -0500",
"is_openbsd": false,
"thread_id": "20260206-amlogic-dma-v3-0-56fb9f59ed22@amlogic.com.mbox.gz"
} |
lkml_critique | lkml | From: Xianwei Zhao <xianwei.zhao@amlogic.com>
Add Amlogic DMA controller entry to MAINTAINERS to clarify
the maintainers.
Signed-off-by: Xianwei Zhao <xianwei.zhao@amlogic.com>
---
MAINTAINERS | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/MAINTAINERS b/MAINTAINERS
index 5b11839cba9d..9b471d580b32 100644... | null | null | null | [PATCH v3 3/3] MAINTAINERS: Add an entry for Amlogic DMA driver | On Fri, Feb 06, 2026 at 09:02:33AM +0000, Xianwei Zhao wrote:
Leave to Vinod Koul to do decide. This is not preferred implement to prep
tx descriptior.
why not split it and use mult sg_link to transfer it?
there are help functions sg_nents_for_dma()
This is DT ABI, should create header file in include/binding/dma
... | {
"author": "Frank Li <Frank.li@nxp.com>",
"date": "Fri, 6 Feb 2026 14:48:09 -0500",
"is_openbsd": false,
"thread_id": "20260206-amlogic-dma-v3-0-56fb9f59ed22@amlogic.com.mbox.gz"
} |
lkml_critique | lkml | From: Xianwei Zhao <xianwei.zhao@amlogic.com>
Add Amlogic DMA controller entry to MAINTAINERS to clarify
the maintainers.
Signed-off-by: Xianwei Zhao <xianwei.zhao@amlogic.com>
---
MAINTAINERS | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/MAINTAINERS b/MAINTAINERS
index 5b11839cba9d..9b471d580b32 100644... | null | null | null | [PATCH v3 3/3] MAINTAINERS: Add an entry for Amlogic DMA driver | Hi Xianwei,
kernel test robot noticed the following build warnings:
[auto build test WARNING on 3c8a86ed002ab8fb287ee4ec92f0fd6ac5b291d2]
url: https://github.com/intel-lab-lkp/linux/commits/Xianwei-Zhao-via-B4-Relay/dt-bindings-dma-Add-Amlogic-A9-SoC-DMA/20260206-170903
base: 3c8a86ed002ab8fb287ee4ec92f0fd6ac5b... | {
"author": "kernel test robot <lkp@intel.com>",
"date": "Sat, 7 Feb 2026 04:33:26 +0800",
"is_openbsd": false,
"thread_id": "20260206-amlogic-dma-v3-0-56fb9f59ed22@amlogic.com.mbox.gz"
} |
lkml_critique | lkml | From: Xianwei Zhao <xianwei.zhao@amlogic.com>
Add Amlogic DMA controller entry to MAINTAINERS to clarify
the maintainers.
Signed-off-by: Xianwei Zhao <xianwei.zhao@amlogic.com>
---
MAINTAINERS | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/MAINTAINERS b/MAINTAINERS
index 5b11839cba9d..9b471d580b32 100644... | null | null | null | [PATCH v3 3/3] MAINTAINERS: Add an entry for Amlogic DMA driver | Hi Xianwei,
kernel test robot noticed the following build errors:
[auto build test ERROR on 3c8a86ed002ab8fb287ee4ec92f0fd6ac5b291d2]
url: https://github.com/intel-lab-lkp/linux/commits/Xianwei-Zhao-via-B4-Relay/dt-bindings-dma-Add-Amlogic-A9-SoC-DMA/20260206-170903
base: 3c8a86ed002ab8fb287ee4ec92f0fd6ac5b291d... | {
"author": "kernel test robot <lkp@intel.com>",
"date": "Sat, 7 Feb 2026 04:54:53 +0800",
"is_openbsd": false,
"thread_id": "20260206-amlogic-dma-v3-0-56fb9f59ed22@amlogic.com.mbox.gz"
} |
lkml_critique | lkml | From: Xianwei Zhao <xianwei.zhao@amlogic.com>
Add Amlogic DMA controller entry to MAINTAINERS to clarify
the maintainers.
Signed-off-by: Xianwei Zhao <xianwei.zhao@amlogic.com>
---
MAINTAINERS | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/MAINTAINERS b/MAINTAINERS
index 5b11839cba9d..9b471d580b32 100644... | null | null | null | [PATCH v3 3/3] MAINTAINERS: Add an entry for Amlogic DMA driver | Hi Xianwei Zhao,
On Fri, Feb 6, 2026 at 10:03 AM Xianwei Zhao via B4 Relay
<devnull+xianwei.zhao.amlogic.com@kernel.org> wrote:
[...]
I have not seen this way of writing two bits before.
Should this be:
BIT(DMA_SLAVE_BUSWIDTH_4_BYTES) | BIT(DMA_SLAVE_BUSWIDTH_1_BYTE)
instead (similar to the line below)?
Best reg... | {
"author": "Martin Blumenstingl <martin.blumenstingl@googlemail.com>",
"date": "Mon, 9 Feb 2026 22:28:34 +0100",
"is_openbsd": false,
"thread_id": "20260206-amlogic-dma-v3-0-56fb9f59ed22@amlogic.com.mbox.gz"
} |
lkml_critique | lkml | From: Xianwei Zhao <xianwei.zhao@amlogic.com>
Add Amlogic DMA controller entry to MAINTAINERS to clarify
the maintainers.
Signed-off-by: Xianwei Zhao <xianwei.zhao@amlogic.com>
---
MAINTAINERS | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/MAINTAINERS b/MAINTAINERS
index 5b11839cba9d..9b471d580b32 100644... | null | null | null | [PATCH v3 3/3] MAINTAINERS: Add an entry for Amlogic DMA driver | On Fri, Feb 06, 2026 at 09:02:33AM +0000, Xianwei Zhao via B4 Relay wrote:
subject should dmaegine: amlogic: ...
Frank | {
"author": "Frank Li <Frank.li@nxp.com>",
"date": "Fri, 27 Feb 2026 10:54:58 -0500",
"is_openbsd": false,
"thread_id": "20260206-amlogic-dma-v3-0-56fb9f59ed22@amlogic.com.mbox.gz"
} |
lkml_critique | lkml | Peter recently posted a series tweaking the hrtimer subsystem to reduce the
overhead of the scheduler hrtick timer so it can be enabled by default:
https://lore.kernel.org/20260121162010.647043073@infradead.org
That turned out to be incomplete and led to a deeper investigation of the
related bits and pieces.
The ... | null | null | null | [patch 00/48] hrtimer,sched: General optimizations and hrtick
enablement | From: Peter Zijlstra <peterz@infradead.org>
The nominal duration for an EEVDF task to run is until its deadline. At
which point the deadline is moved ahead and a new task selection is done.
Try and predict the time 'lost' to higher scheduling classes. Since this is
an estimate, the timer can be both early or late. In... | {
"author": "Thomas Gleixner <tglx@kernel.org>",
"date": "Tue, 24 Feb 2026 17:35:17 +0100",
"is_openbsd": false,
"thread_id": "51f8535f-b98c-48e3-ba7b-f28759a92c16@arm.com.mbox.gz"
} |
lkml_critique | lkml | Peter recently posted a series tweaking the hrtimer subsystem to reduce the
overhead of the scheduler hrtick timer so it can be enabled by default:
https://lore.kernel.org/20260121162010.647043073@infradead.org
That turned out to be incomplete and led to a deeper investigation of the
related bits and pieces.
The ... | null | null | null | [patch 00/48] hrtimer,sched: General optimizations and hrtick
enablement | From: Peter Zijlstra (Intel) <peterz@infradead.org>
hrtick_update() was needed when the slice depended on nr_running, all that
code is gone. All that remains is starting the hrtick when nr_running
becomes more than 1.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@ke... | {
"author": "Thomas Gleixner <tglx@kernel.org>",
"date": "Tue, 24 Feb 2026 17:35:22 +0100",
"is_openbsd": false,
"thread_id": "51f8535f-b98c-48e3-ba7b-f28759a92c16@arm.com.mbox.gz"
} |
lkml_critique | lkml | Peter recently posted a series tweaking the hrtimer subsystem to reduce the
overhead of the scheduler hrtick timer so it can be enabled by default:
https://lore.kernel.org/20260121162010.647043073@infradead.org
That turned out to be incomplete and led to a deeper investigation of the
related bits and pieces.
The ... | null | null | null | [patch 00/48] hrtimer,sched: General optimizations and hrtick
enablement | From: Peter Zijlstra (Intel) <peterz@infradead.org>
Since the tick causes hard preemption, the hrtick should too.
Letting the hrtick do lazy preemption completely defeats the purpose, since
it will then still be delayed until a old tick and be dependent on
CONFIG_HZ.
Signed-off-by: Peter Zijlstra (Intel) <peterz@inf... | {
"author": "Thomas Gleixner <tglx@kernel.org>",
"date": "Tue, 24 Feb 2026 17:35:27 +0100",
"is_openbsd": false,
"thread_id": "51f8535f-b98c-48e3-ba7b-f28759a92c16@arm.com.mbox.gz"
} |
lkml_critique | lkml | Peter recently posted a series tweaking the hrtimer subsystem to reduce the
overhead of the scheduler hrtick timer so it can be enabled by default:
https://lore.kernel.org/20260121162010.647043073@infradead.org
That turned out to be incomplete and led to a deeper investigation of the
related bits and pieces.
The ... | null | null | null | [patch 00/48] hrtimer,sched: General optimizations and hrtick
enablement | The clock of the hrtick and deadline timers is known to be CLOCK_MONOTONIC.
No point in looking it up via hrtimer_cb_get_time().
Just use ktime_get() directly.
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
---
kernel/sched/core.c | 3 +--
kernel/sched/deadline.c | 2 +-
2 files changed, 2 insertions(+),... | {
"author": "Thomas Gleixner <tglx@kernel.org>",
"date": "Tue, 24 Feb 2026 17:35:32 +0100",
"is_openbsd": false,
"thread_id": "51f8535f-b98c-48e3-ba7b-f28759a92c16@arm.com.mbox.gz"
} |
lkml_critique | lkml | Peter recently posted a series tweaking the hrtimer subsystem to reduce the
overhead of the scheduler hrtick timer so it can be enabled by default:
https://lore.kernel.org/20260121162010.647043073@infradead.org
That turned out to be incomplete and led to a deeper investigation of the
related bits and pieces.
The ... | null | null | null | [patch 00/48] hrtimer,sched: General optimizations and hrtick
enablement | From: Peter Zijlstra <peterz@infradead.org>
Much like hrtimer_reprogram(), skip programming if the cpu_base is running
the hrtimer interrupt.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Reviewed-by: Juri Lelli <juri.lelli@redhat.com>
Reviewed-by: Thoma... | {
"author": "Thomas Gleixner <tglx@kernel.org>",
"date": "Tue, 24 Feb 2026 17:35:37 +0100",
"is_openbsd": false,
"thread_id": "51f8535f-b98c-48e3-ba7b-f28759a92c16@arm.com.mbox.gz"
} |
lkml_critique | lkml | Peter recently posted a series tweaking the hrtimer subsystem to reduce the
overhead of the scheduler hrtick timer so it can be enabled by default:
https://lore.kernel.org/20260121162010.647043073@infradead.org
That turned out to be incomplete and led to a deeper investigation of the
related bits and pieces.
The ... | null | null | null | [patch 00/48] hrtimer,sched: General optimizations and hrtick
enablement | The scheduler evaluates this via hrtimer_is_hres_active() every time it has
to update HRTICK. This needs to follow three pointers, which is expensive.
Provide a static branch based mechanism to avoid that.
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
---
include/linux/hrtimer.h | 13 +++++++++----
kernel/time/... | {
"author": "Thomas Gleixner <tglx@kernel.org>",
"date": "Tue, 24 Feb 2026 17:35:42 +0100",
"is_openbsd": false,
"thread_id": "51f8535f-b98c-48e3-ba7b-f28759a92c16@arm.com.mbox.gz"
} |
lkml_critique | lkml | Peter recently posted a series tweaking the hrtimer subsystem to reduce the
overhead of the scheduler hrtick timer so it can be enabled by default:
https://lore.kernel.org/20260121162010.647043073@infradead.org
That turned out to be incomplete and led to a deeper investigation of the
related bits and pieces.
The ... | null | null | null | [patch 00/48] hrtimer,sched: General optimizations and hrtick
enablement | Use the static branch based variant and thereby avoid following three
pointers.
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
---
include/linux/hrtimer.h | 6 ------
kernel/sched/sched.h | 37 +++++++++----------------------------
2 files changed, 9 insertions(+), 34 deletions(-)
--- a/include/linux/hrtim... | {
"author": "Thomas Gleixner <tglx@kernel.org>",
"date": "Tue, 24 Feb 2026 17:35:47 +0100",
"is_openbsd": false,
"thread_id": "51f8535f-b98c-48e3-ba7b-f28759a92c16@arm.com.mbox.gz"
} |
lkml_critique | lkml | Peter recently posted a series tweaking the hrtimer subsystem to reduce the
overhead of the scheduler hrtick timer so it can be enabled by default:
https://lore.kernel.org/20260121162010.647043073@infradead.org
That turned out to be incomplete and led to a deeper investigation of the
related bits and pieces.
The ... | null | null | null | [patch 00/48] hrtimer,sched: General optimizations and hrtick
enablement | schedule() provides several mechanisms to update the hrtick timer:
1) When the next task is picked
2) When the balance callbacks are invoked before rq::lock is released
Each of them can result in a first expiring timer and cause a reprogram of
the clock event device.
Solve this by deferring the rearm to the end... | {
"author": "Thomas Gleixner <tglx@kernel.org>",
"date": "Tue, 24 Feb 2026 17:35:52 +0100",
"is_openbsd": false,
"thread_id": "51f8535f-b98c-48e3-ba7b-f28759a92c16@arm.com.mbox.gz"
} |
lkml_critique | lkml | Peter recently posted a series tweaking the hrtimer subsystem to reduce the
overhead of the scheduler hrtick timer so it can be enabled by default:
https://lore.kernel.org/20260121162010.647043073@infradead.org
That turned out to be incomplete and led to a deeper investigation of the
related bits and pieces.
The ... | null | null | null | [patch 00/48] hrtimer,sched: General optimizations and hrtick
enablement | Tiny adjustments to the hrtick expiry time below 5 microseconds are just
causing extra work for no real value. Filter them out when restarting the
hrtick.
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
---
kernel/sched/core.c | 24 +++++++++++++++++++-----
1 file changed, 19 insertions(+), 5 deletions(-)
--- a/k... | {
"author": "Thomas Gleixner <tglx@kernel.org>",
"date": "Tue, 24 Feb 2026 17:35:56 +0100",
"is_openbsd": false,
"thread_id": "51f8535f-b98c-48e3-ba7b-f28759a92c16@arm.com.mbox.gz"
} |
lkml_critique | lkml | Peter recently posted a series tweaking the hrtimer subsystem to reduce the
overhead of the scheduler hrtick timer so it can be enabled by default:
https://lore.kernel.org/20260121162010.647043073@infradead.org
That turned out to be incomplete and led to a deeper investigation of the
related bits and pieces.
The ... | null | null | null | [patch 00/48] hrtimer,sched: General optimizations and hrtick
enablement | From: Peter Zijlstra <peterz@infradead.org>
The hrtick timer is frequently rearmed before expiry and most of the time
the new expiry is past the armed one. As this happens on every context
switch it becomes expensive with scheduling heavy work loads especially in
virtual machines as the "hardware" reprogamming implies... | {
"author": "Thomas Gleixner <tglx@kernel.org>",
"date": "Tue, 24 Feb 2026 17:36:01 +0100",
"is_openbsd": false,
"thread_id": "51f8535f-b98c-48e3-ba7b-f28759a92c16@arm.com.mbox.gz"
} |
lkml_critique | lkml | Peter recently posted a series tweaking the hrtimer subsystem to reduce the
overhead of the scheduler hrtick timer so it can be enabled by default:
https://lore.kernel.org/20260121162010.647043073@infradead.org
That turned out to be incomplete and led to a deeper investigation of the
related bits and pieces.
The ... | null | null | null | [patch 00/48] hrtimer,sched: General optimizations and hrtick
enablement | From: Peter Zijlstra <peterz@infradead.org>
The hrtick timer is frequently rearmed before expiry and most of the time
the new expiry is past the armed one. As this happens on every context
switch it becomes expensive with scheduling heavy work loads especially in
virtual machines as the "hardware" reprogamming implies... | {
"author": "Thomas Gleixner <tglx@kernel.org>",
"date": "Tue, 24 Feb 2026 17:36:06 +0100",
"is_openbsd": false,
"thread_id": "51f8535f-b98c-48e3-ba7b-f28759a92c16@arm.com.mbox.gz"
} |
lkml_critique | lkml | Peter recently posted a series tweaking the hrtimer subsystem to reduce the
overhead of the scheduler hrtick timer so it can be enabled by default:
https://lore.kernel.org/20260121162010.647043073@infradead.org
That turned out to be incomplete and led to a deeper investigation of the
related bits and pieces.
The ... | null | null | null | [patch 00/48] hrtimer,sched: General optimizations and hrtick
enablement | The sequence of cancel and start is inefficient. It has to do the timer
lock/unlock twice and in the worst case has to reprogram the underlying
clock event device twice.
The reason why it is done this way is the usage of hrtimer_forward_now(),
which requires the timer to be inactive.
But that can be completely avoide... | {
"author": "Thomas Gleixner <tglx@kernel.org>",
"date": "Tue, 24 Feb 2026 17:36:10 +0100",
"is_openbsd": false,
"thread_id": "51f8535f-b98c-48e3-ba7b-f28759a92c16@arm.com.mbox.gz"
} |
lkml_critique | lkml | Peter recently posted a series tweaking the hrtimer subsystem to reduce the
overhead of the scheduler hrtick timer so it can be enabled by default:
https://lore.kernel.org/20260121162010.647043073@infradead.org
That turned out to be incomplete and led to a deeper investigation of the
related bits and pieces.
The ... | null | null | null | [patch 00/48] hrtimer,sched: General optimizations and hrtick
enablement | The only real usecase for this is the hrtimer based broadcast device.
No point in using two different feature flags for this.
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
---
include/linux/clockchips.h | 1 -
kernel/time/clockevents.c | 4 ++--
kernel/time/tick-broadcast-hrtimer.c | ... | {
"author": "Thomas Gleixner <tglx@kernel.org>",
"date": "Tue, 24 Feb 2026 17:36:15 +0100",
"is_openbsd": false,
"thread_id": "51f8535f-b98c-48e3-ba7b-f28759a92c16@arm.com.mbox.gz"
} |
lkml_critique | lkml | Peter recently posted a series tweaking the hrtimer subsystem to reduce the
overhead of the scheduler hrtick timer so it can be enabled by default:
https://lore.kernel.org/20260121162010.647043073@infradead.org
That turned out to be incomplete and led to a deeper investigation of the
related bits and pieces.
The ... | null | null | null | [patch 00/48] hrtimer,sched: General optimizations and hrtick
enablement | On some architectures clocksource::read() boils down to a single
instruction, so the indirect function call is just a massive overhead
especially with speculative execution mitigations in effect.
Allow architectures to enable conditional inlining of that read to avoid
that by:
- providing a static branch to switch... | {
"author": "Thomas Gleixner <tglx@kernel.org>",
"date": "Tue, 24 Feb 2026 17:36:20 +0100",
"is_openbsd": false,
"thread_id": "51f8535f-b98c-48e3-ba7b-f28759a92c16@arm.com.mbox.gz"
} |
lkml_critique | lkml | Peter recently posted a series tweaking the hrtimer subsystem to reduce the
overhead of the scheduler hrtick timer so it can be enabled by default:
https://lore.kernel.org/20260121162010.647043073@infradead.org
That turned out to be incomplete and led to a deeper investigation of the
related bits and pieces.
The ... | null | null | null | [patch 00/48] hrtimer,sched: General optimizations and hrtick
enablement | Avoid the overhead of the indirect call for a single instruction to read
the TSC.
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
---
arch/x86/Kconfig | 1 +
arch/x86/include/asm/clock_inlined.h | 14 ++++++++++++++
arch/x86/kernel/tsc.c | 1 +
3 files changed, 16 insertion... | {
"author": "Thomas Gleixner <tglx@kernel.org>",
"date": "Tue, 24 Feb 2026 17:36:24 +0100",
"is_openbsd": false,
"thread_id": "51f8535f-b98c-48e3-ba7b-f28759a92c16@arm.com.mbox.gz"
} |
lkml_critique | lkml | Peter recently posted a series tweaking the hrtimer subsystem to reduce the
overhead of the scheduler hrtick timer so it can be enabled by default:
https://lore.kernel.org/20260121162010.647043073@infradead.org
That turned out to be incomplete and led to a deeper investigation of the
related bits and pieces.
The ... | null | null | null | [patch 00/48] hrtimer,sched: General optimizations and hrtick
enablement | lapic_next_deadline() contains a fence before the TSC read and the write to
the TSC_DEADLINE MSR with a content free and therefore useless comment:
/* This MSR is special and need a special fence: */
The MSR is not really special. It is just not a serializing MSR, but that
does not matter at all in this context a... | {
"author": "Thomas Gleixner <tglx@kernel.org>",
"date": "Tue, 24 Feb 2026 17:36:29 +0100",
"is_openbsd": false,
"thread_id": "51f8535f-b98c-48e3-ba7b-f28759a92c16@arm.com.mbox.gz"
} |
lkml_critique | lkml | Peter recently posted a series tweaking the hrtimer subsystem to reduce the
overhead of the scheduler hrtick timer so it can be enabled by default:
https://lore.kernel.org/20260121162010.647043073@infradead.org
That turned out to be incomplete and led to a deeper investigation of the
related bits and pieces.
The ... | null | null | null | [patch 00/48] hrtimer,sched: General optimizations and hrtick
enablement | XEN PV does not emulate the TSC deadline timer, so the PVOPS indirection
for writing the deadline MSR can be avoided completely.
Use native_wrmsrq() instead.
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
---
arch/x86/kernel/apic/apic.c | 13 ++++++++++---
1 file changed, 10 insertions(+), 3 deletions(-)
--- a/... | {
"author": "Thomas Gleixner <tglx@kernel.org>",
"date": "Tue, 24 Feb 2026 17:36:34 +0100",
"is_openbsd": false,
"thread_id": "51f8535f-b98c-48e3-ba7b-f28759a92c16@arm.com.mbox.gz"
} |
lkml_critique | lkml | Peter recently posted a series tweaking the hrtimer subsystem to reduce the
overhead of the scheduler hrtick timer so it can be enabled by default:
https://lore.kernel.org/20260121162010.647043073@infradead.org
That turned out to be incomplete and led to a deeper investigation of the
related bits and pieces.
The ... | null | null | null | [patch 00/48] hrtimer,sched: General optimizations and hrtick
enablement | Some architectures have clockevent devices which are coupled to the system
clocksource by implementing a less than or equal comparator which compares
the programmed absolute expiry time against the underlying time
counter. Well known examples are TSC/TSC deadline timer and the S390 TOD
clocksource/comparator.
While th... | {
"author": "Thomas Gleixner <tglx@kernel.org>",
"date": "Tue, 24 Feb 2026 17:36:40 +0100",
"is_openbsd": false,
"thread_id": "51f8535f-b98c-48e3-ba7b-f28759a92c16@arm.com.mbox.gz"
} |
lkml_critique | lkml | Peter recently posted a series tweaking the hrtimer subsystem to reduce the
overhead of the scheduler hrtick timer so it can be enabled by default:
https://lore.kernel.org/20260121162010.647043073@infradead.org
That turned out to be incomplete and led to a deeper investigation of the
related bits and pieces.
The ... | null | null | null | [patch 00/48] hrtimer,sched: General optimizations and hrtick
enablement | Some clockevent devices are coupled to the system clocksource by
implementing a less than or equal comparator which compares the programmed
absolute expiry time against the underlying time counter.
The timekeeping core provides a function to convert and absolute
CLOCK_MONOTONIC based expiry time to a absolute clock cy... | {
"author": "Thomas Gleixner <tglx@kernel.org>",
"date": "Tue, 24 Feb 2026 17:36:45 +0100",
"is_openbsd": false,
"thread_id": "51f8535f-b98c-48e3-ba7b-f28759a92c16@arm.com.mbox.gz"
} |
lkml_critique | lkml | Peter recently posted a series tweaking the hrtimer subsystem to reduce the
overhead of the scheduler hrtick timer so it can be enabled by default:
https://lore.kernel.org/20260121162010.647043073@infradead.org
That turned out to be incomplete and led to a deeper investigation of the
related bits and pieces.
The ... | null | null | null | [patch 00/48] hrtimer,sched: General optimizations and hrtick
enablement | The TSC deadline timer is directly coupled to the TSC and setting the next
deadline is tedious as the clockevents core code converts the
CLOCK_MONOTONIC based absolute expiry time to a relative expiry by reading
the current time from the TSC. It converts that delta to cycles and hands
the result to lapic_next_deadline(... | {
"author": "Thomas Gleixner <tglx@kernel.org>",
"date": "Tue, 24 Feb 2026 17:36:49 +0100",
"is_openbsd": false,
"thread_id": "51f8535f-b98c-48e3-ba7b-f28759a92c16@arm.com.mbox.gz"
} |
lkml_critique | lkml | Peter recently posted a series tweaking the hrtimer subsystem to reduce the
overhead of the scheduler hrtick timer so it can be enabled by default:
https://lore.kernel.org/20260121162010.647043073@infradead.org
That turned out to be incomplete and led to a deeper investigation of the
related bits and pieces.
The ... | null | null | null | [patch 00/48] hrtimer,sched: General optimizations and hrtick
enablement | The debug object coverage in hrtimer_start_range_ns() happens too late to
do anything useful. Implement the init assert assertion part and invoke
that early in hrtimer_start_range_ns().
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
---
kernel/time/hrtimer.c | 43 ++++++++++++++++++++++++++++++++++++++-----
1 fil... | {
"author": "Thomas Gleixner <tglx@kernel.org>",
"date": "Tue, 24 Feb 2026 17:36:54 +0100",
"is_openbsd": false,
"thread_id": "51f8535f-b98c-48e3-ba7b-f28759a92c16@arm.com.mbox.gz"
} |
lkml_critique | lkml | Peter recently posted a series tweaking the hrtimer subsystem to reduce the
overhead of the scheduler hrtick timer so it can be enabled by default:
https://lore.kernel.org/20260121162010.647043073@infradead.org
That turned out to be incomplete and led to a deeper investigation of the
related bits and pieces.
The ... | null | null | null | [patch 00/48] hrtimer,sched: General optimizations and hrtick
enablement | hrtimer_start() when invoked with an already armed timer traces like:
<comm>-.. [032] d.h2. 5.002263: hrtimer_cancel: hrtimer= ....
<comm>-.. [032] d.h1. 5.002263: hrtimer_start: hrtimer= ....
Which is incorrect as the timer doesn't get canceled. Just the expiry time
changes. The internal dequeue operat... | {
"author": "Thomas Gleixner <tglx@kernel.org>",
"date": "Tue, 24 Feb 2026 17:36:59 +0100",
"is_openbsd": false,
"thread_id": "51f8535f-b98c-48e3-ba7b-f28759a92c16@arm.com.mbox.gz"
} |
lkml_critique | lkml | Peter recently posted a series tweaking the hrtimer subsystem to reduce the
overhead of the scheduler hrtick timer so it can be enabled by default:
https://lore.kernel.org/20260121162010.647043073@infradead.org
That turned out to be incomplete and led to a deeper investigation of the
related bits and pieces.
The ... | null | null | null | [patch 00/48] hrtimer,sched: General optimizations and hrtick
enablement | Simplify and tidy up the code where possible.
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
---
kernel/time/hrtimer.c | 48 +++++++++++++++---------------------------------
1 file changed, 15 insertions(+), 33 deletions(-)
--- a/kernel/time/hrtimer.c
+++ b/kernel/time/hrtimer.c
@@ -838,13 +838,12 @@ static void... | {
"author": "Thomas Gleixner <tglx@kernel.org>",
"date": "Tue, 24 Feb 2026 17:37:04 +0100",
"is_openbsd": false,
"thread_id": "51f8535f-b98c-48e3-ba7b-f28759a92c16@arm.com.mbox.gz"
} |
lkml_critique | lkml | Peter recently posted a series tweaking the hrtimer subsystem to reduce the
overhead of the scheduler hrtick timer so it can be enabled by default:
https://lore.kernel.org/20260121162010.647043073@infradead.org
That turned out to be incomplete and led to a deeper investigation of the
related bits and pieces.
The ... | null | null | null | [patch 00/48] hrtimer,sched: General optimizations and hrtick
enablement | No point in accessing the timer twice.
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
---
kernel/time/hrtimer.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
--- a/kernel/time/hrtimer.c
+++ b/kernel/time/hrtimer.c
@@ -810,10 +810,11 @@ static void hrtimer_reprogram(struct hrt
{
struct hrtimer_cp... | {
"author": "Thomas Gleixner <tglx@kernel.org>",
"date": "Tue, 24 Feb 2026 17:37:14 +0100",
"is_openbsd": false,
"thread_id": "51f8535f-b98c-48e3-ba7b-f28759a92c16@arm.com.mbox.gz"
} |
lkml_critique | lkml | Peter recently posted a series tweaking the hrtimer subsystem to reduce the
overhead of the scheduler hrtick timer so it can be enabled by default:
https://lore.kernel.org/20260121162010.647043073@infradead.org
That turned out to be incomplete and led to a deeper investigation of the
related bits and pieces.
The ... | null | null | null | [patch 00/48] hrtimer,sched: General optimizations and hrtick
enablement | As this code has some major surgery ahead, clean up coding style and bring
comments up to date.
No functional change intended.
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
---
kernel/time/hrtimer.c | 364 +++++++++++++++++++-------------------------------
1 file changed, 143 insertions(+), 221 deletions(-)
---... | {
"author": "Thomas Gleixner <tglx@kernel.org>",
"date": "Tue, 24 Feb 2026 17:37:09 +0100",
"is_openbsd": false,
"thread_id": "51f8535f-b98c-48e3-ba7b-f28759a92c16@arm.com.mbox.gz"
} |
lkml_critique | lkml | Peter recently posted a series tweaking the hrtimer subsystem to reduce the
overhead of the scheduler hrtick timer so it can be enabled by default:
https://lore.kernel.org/20260121162010.647043073@infradead.org
That turned out to be incomplete and led to a deeper investigation of the
related bits and pieces.
The ... | null | null | null | [patch 00/48] hrtimer,sched: General optimizations and hrtick
enablement | Use bool for the various flags as that creates better code in the hot path.
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
---
include/linux/hrtimer_defs.h | 10 +++++-----
kernel/time/hrtimer.c | 25 +++++++++++++------------
2 files changed, 18 insertions(+), 17 deletions(-)
--- a/include/linux/hrtime... | {
"author": "Thomas Gleixner <tglx@kernel.org>",
"date": "Tue, 24 Feb 2026 17:37:18 +0100",
"is_openbsd": false,
"thread_id": "51f8535f-b98c-48e3-ba7b-f28759a92c16@arm.com.mbox.gz"
} |
lkml_critique | lkml | Peter recently posted a series tweaking the hrtimer subsystem to reduce the
overhead of the scheduler hrtick timer so it can be enabled by default:
https://lore.kernel.org/20260121162010.647043073@infradead.org
That turned out to be incomplete and led to a deeper investigation of the
related bits and pieces.
The ... | null | null | null | [patch 00/48] hrtimer,sched: General optimizations and hrtick
enablement | All 'u8' flags are true booleans, so make it entirely clear that these can
only contain true or false.
This is especially true for hrtimer::state, which has a historical leftover
of using the state with bitwise operations. That was used in the early
hrtimer implementation with several bits, but then converted to a boo... | {
"author": "Thomas Gleixner <tglx@kernel.org>",
"date": "Tue, 24 Feb 2026 17:37:23 +0100",
"is_openbsd": false,
"thread_id": "51f8535f-b98c-48e3-ba7b-f28759a92c16@arm.com.mbox.gz"
} |
lkml_critique | lkml | Peter recently posted a series tweaking the hrtimer subsystem to reduce the
overhead of the scheduler hrtick timer so it can be enabled by default:
https://lore.kernel.org/20260121162010.647043073@infradead.org
That turned out to be incomplete and led to a deeper investigation of the
related bits and pieces.
The ... | null | null | null | [patch 00/48] hrtimer,sched: General optimizations and hrtick
enablement | The decision whether to keep timers on the local CPU or on the CPU they are
associated to is suboptimal and causes the expensive switch_hrtimer_base()
mechanism to be invoked more than necessary. This is especially true for
pinned timers.
Rewrite the decision logic so that the current base is kept if:
1) The callb... | {
"author": "Thomas Gleixner <tglx@kernel.org>",
"date": "Tue, 24 Feb 2026 17:37:28 +0100",
"is_openbsd": false,
"thread_id": "51f8535f-b98c-48e3-ba7b-f28759a92c16@arm.com.mbox.gz"
} |
lkml_critique | lkml | Peter recently posted a series tweaking the hrtimer subsystem to reduce the
overhead of the scheduler hrtick timer so it can be enabled by default:
https://lore.kernel.org/20260121162010.647043073@infradead.org
That turned out to be incomplete and led to a deeper investigation of the
related bits and pieces.
The ... | null | null | null | [patch 00/48] hrtimer,sched: General optimizations and hrtick
enablement | The decision to keep a timer which is associated to the local CPU on that
CPU does not take NOHZ information into account. As a result there are a
lot of hrtimer base switch invocations which end up not switching the base
and stay on the local CPU. That's just work for nothing and can be further
improved.
If the local... | {
"author": "Thomas Gleixner <tglx@kernel.org>",
"date": "Tue, 24 Feb 2026 17:37:33 +0100",
"is_openbsd": false,
"thread_id": "51f8535f-b98c-48e3-ba7b-f28759a92c16@arm.com.mbox.gz"
} |
lkml_critique | lkml | Peter recently posted a series tweaking the hrtimer subsystem to reduce the
overhead of the scheduler hrtick timer so it can be enabled by default:
https://lore.kernel.org/20260121162010.647043073@infradead.org
That turned out to be incomplete and led to a deeper investigation of the
related bits and pieces.
The ... | null | null | null | [patch 00/48] hrtimer,sched: General optimizations and hrtick
enablement | As the base switch can be avoided completely when the base stays the same
the remove/enqueue handling can be more streamlined.
Split it out into a separate function which handles both in one go which is
way more efficient and makes the code simpler to follow.
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
---
kern... | {
"author": "Thomas Gleixner <tglx@kernel.org>",
"date": "Tue, 24 Feb 2026 17:37:38 +0100",
"is_openbsd": false,
"thread_id": "51f8535f-b98c-48e3-ba7b-f28759a92c16@arm.com.mbox.gz"
} |
lkml_critique | lkml | Peter recently posted a series tweaking the hrtimer subsystem to reduce the
overhead of the scheduler hrtick timer so it can be enabled by default:
https://lore.kernel.org/20260121162010.647043073@infradead.org
That turned out to be incomplete and led to a deeper investigation of the
related bits and pieces.
The ... | null | null | null | [patch 00/48] hrtimer,sched: General optimizations and hrtick
enablement | Analyzing the reprogramming of the clock event device is essential to debug
the behaviour of the hrtimer subsystem especially with the upcoming
deferred rearming scheme.
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
---
include/trace/events/timer.h | 24 ++++++++++++++++++++++++
1 file changed, 24 insertions(+)
... | {
"author": "Thomas Gleixner <tglx@kernel.org>",
"date": "Tue, 24 Feb 2026 17:37:43 +0100",
"is_openbsd": false,
"thread_id": "51f8535f-b98c-48e3-ba7b-f28759a92c16@arm.com.mbox.gz"
} |
lkml_critique | lkml | Peter recently posted a series tweaking the hrtimer subsystem to reduce the
overhead of the scheduler hrtick timer so it can be enabled by default:
https://lore.kernel.org/20260121162010.647043073@infradead.org
That turned out to be incomplete and led to a deeper investigation of the
related bits and pieces.
The ... | null | null | null | [patch 00/48] hrtimer,sched: General optimizations and hrtick
enablement | From: Peter Zijlstra <peterz@infradead.org>
Rework hrtimer_interrupt() such that reprogramming is split out into an
independent function at the end of the interrupt.
This prepares for reprogramming getting delayed beyond the end of
hrtimer_interrupt().
Notably, this changes the hang handling to always wait 100ms ins... | {
"author": "Thomas Gleixner <tglx@kernel.org>",
"date": "Tue, 24 Feb 2026 17:37:48 +0100",
"is_openbsd": false,
"thread_id": "51f8535f-b98c-48e3-ba7b-f28759a92c16@arm.com.mbox.gz"
} |
lkml_critique | lkml | Peter recently posted a series tweaking the hrtimer subsystem to reduce the
overhead of the scheduler hrtick timer so it can be enabled by default:
https://lore.kernel.org/20260121162010.647043073@infradead.org
That turned out to be incomplete and led to a deeper investigation of the
related bits and pieces.
The ... | null | null | null | [patch 00/48] hrtimer,sched: General optimizations and hrtick
enablement | The upcoming deferred rearming scheme has the same effect as the deferred
rearming when the hrtimer interrupt is executing. So it can reuse the
in_hrtirq flag, but when it gets deferred beyond the hrtimer interrupt
path, then the name does not make sense anymore.
Rename it to deferred_rearm upfront to keep the actual ... | {
"author": "Thomas Gleixner <tglx@kernel.org>",
"date": "Tue, 24 Feb 2026 17:37:53 +0100",
"is_openbsd": false,
"thread_id": "51f8535f-b98c-48e3-ba7b-f28759a92c16@arm.com.mbox.gz"
} |
lkml_critique | lkml | Peter recently posted a series tweaking the hrtimer subsystem to reduce the
overhead of the scheduler hrtick timer so it can be enabled by default:
https://lore.kernel.org/20260121162010.647043073@infradead.org
That turned out to be incomplete and led to a deeper investigation of the
related bits and pieces.
The ... | null | null | null | [patch 00/48] hrtimer,sched: General optimizations and hrtick
enablement | From: Peter Zijlstra <peterz@infradead.org>
The hrtimer interrupt expires timers and at the end of the interrupt it
rearms the clockevent device for the next expiring timer.
That's obviously correct, but in the case that a expired timer set
NEED_RESCHED the return from interrupt ends up in schedule(). If HRTICK is
en... | {
"author": "Thomas Gleixner <tglx@kernel.org>",
"date": "Tue, 24 Feb 2026 17:37:58 +0100",
"is_openbsd": false,
"thread_id": "51f8535f-b98c-48e3-ba7b-f28759a92c16@arm.com.mbox.gz"
} |
lkml_critique | lkml | Peter recently posted a series tweaking the hrtimer subsystem to reduce the
overhead of the scheduler hrtick timer so it can be enabled by default:
https://lore.kernel.org/20260121162010.647043073@infradead.org
That turned out to be incomplete and led to a deeper investigation of the
related bits and pieces.
The ... | null | null | null | [patch 00/48] hrtimer,sched: General optimizations and hrtick
enablement | From: Peter Zijlstra <peterz@infradead.org>
The hrtimer interrupt expires timers and at the end of the interrupt it
rearms the clockevent device for the next expiring timer.
That's obviously correct, but in the case that a expired timer sets
NEED_RESCHED the return from interrupt ends up in schedule(). If HRTICK is
e... | {
"author": "Thomas Gleixner <tglx@kernel.org>",
"date": "Tue, 24 Feb 2026 17:38:03 +0100",
"is_openbsd": false,
"thread_id": "51f8535f-b98c-48e3-ba7b-f28759a92c16@arm.com.mbox.gz"
} |
lkml_critique | lkml | Peter recently posted a series tweaking the hrtimer subsystem to reduce the
overhead of the scheduler hrtick timer so it can be enabled by default:
https://lore.kernel.org/20260121162010.647043073@infradead.org
That turned out to be incomplete and led to a deeper investigation of the
related bits and pieces.
The ... | null | null | null | [patch 00/48] hrtimer,sched: General optimizations and hrtick
enablement | From: Peter Zijlstra <peterz@infradead.org>
The hrtimer interrupt expires timers and at the end of the interrupt it
rearms the clockevent device for the next expiring timer.
That's obviously correct, but in the case that a expired timer sets
NEED_RESCHED the return from interrupt ends up in schedule(). If HRTICK is
e... | {
"author": "Thomas Gleixner <tglx@kernel.org>",
"date": "Tue, 24 Feb 2026 17:38:07 +0100",
"is_openbsd": false,
"thread_id": "51f8535f-b98c-48e3-ba7b-f28759a92c16@arm.com.mbox.gz"
} |
lkml_critique | lkml | Peter recently posted a series tweaking the hrtimer subsystem to reduce the
overhead of the scheduler hrtick timer so it can be enabled by default:
https://lore.kernel.org/20260121162010.647043073@infradead.org
That turned out to be incomplete and led to a deeper investigation of the
related bits and pieces.
The ... | null | null | null | [patch 00/48] hrtimer,sched: General optimizations and hrtick
enablement | From: Peter Zijlstra <peterz@infradead.org>
The hrtimer interrupt expires timers and at the end of the interrupt it
rearms the clockevent device for the next expiring timer.
That's obviously correct, but in the case that a expired timer sets
NEED_RESCHED the return from interrupt ends up in schedule(). If HRTICK is
e... | {
"author": "Thomas Gleixner <tglx@kernel.org>",
"date": "Tue, 24 Feb 2026 17:38:12 +0100",
"is_openbsd": false,
"thread_id": "51f8535f-b98c-48e3-ba7b-f28759a92c16@arm.com.mbox.gz"
} |
lkml_critique | lkml | Peter recently posted a series tweaking the hrtimer subsystem to reduce the
overhead of the scheduler hrtick timer so it can be enabled by default:
https://lore.kernel.org/20260121162010.647043073@infradead.org
That turned out to be incomplete and led to a deeper investigation of the
related bits and pieces.
The ... | null | null | null | [patch 00/48] hrtimer,sched: General optimizations and hrtick
enablement | From: Peter Zijlstra <peterz@infradead.org>
Currently hrtimer_interrupt() runs expired timers, which can re-arm
themselves, after which it computes the next expiration time and
re-programs the hardware.
However, things like HRTICK, a highres timer driving preemption, cannot
re-arm itself at the point of running, sinc... | {
"author": "Thomas Gleixner <tglx@kernel.org>",
"date": "Tue, 24 Feb 2026 17:38:18 +0100",
"is_openbsd": false,
"thread_id": "51f8535f-b98c-48e3-ba7b-f28759a92c16@arm.com.mbox.gz"
} |
lkml_critique | lkml | Peter recently posted a series tweaking the hrtimer subsystem to reduce the
overhead of the scheduler hrtick timer so it can be enabled by default:
https://lore.kernel.org/20260121162010.647043073@infradead.org
That turned out to be incomplete and led to a deeper investigation of the
related bits and pieces.
The ... | null | null | null | [patch 00/48] hrtimer,sched: General optimizations and hrtick
enablement | Most times there is no change between hrtimer_interrupt() deferring the rearm
and the invocation of hrtimer_rearm_deferred(). In those cases it's a pointless
exercise to re-evaluate the next expiring timer.
Cache the required data and use it if nothing changed.
Signed-off-by: Thomas Gleixner <tglx@kernel.org
---
inc... | {
"author": "Thomas Gleixner <tglx@kernel.org>",
"date": "Tue, 24 Feb 2026 17:38:23 +0100",
"is_openbsd": false,
"thread_id": "51f8535f-b98c-48e3-ba7b-f28759a92c16@arm.com.mbox.gz"
} |
lkml_critique | lkml | Peter recently posted a series tweaking the hrtimer subsystem to reduce the
overhead of the scheduler hrtick timer so it can be enabled by default:
https://lore.kernel.org/20260121162010.647043073@infradead.org
That turned out to be incomplete and led to a deeper investigation of the
related bits and pieces.
The ... | null | null | null | [patch 00/48] hrtimer,sched: General optimizations and hrtick
enablement | Evaluating the next expiry time of all clock bases is cache line expensive
as the expiry time of the first expiring timer is not cached in the base
and requires to access the timer itself, which is definitely in a different
cache line.
It's way more efficient to keep track of the expiry time on enqueue and
dequeue ope... | {
"author": "Thomas Gleixner <tglx@kernel.org>",
"date": "Tue, 24 Feb 2026 17:38:28 +0100",
"is_openbsd": false,
"thread_id": "51f8535f-b98c-48e3-ba7b-f28759a92c16@arm.com.mbox.gz"
} |
lkml_critique | lkml | Peter recently posted a series tweaking the hrtimer subsystem to reduce the
overhead of the scheduler hrtick timer so it can be enabled by default:
https://lore.kernel.org/20260121162010.647043073@infradead.org
That turned out to be incomplete and led to a deeper investigation of the
related bits and pieces.
The ... | null | null | null | [patch 00/48] hrtimer,sched: General optimizations and hrtick
enablement | The per clock base cached expiry time allows to do a more efficient
evaluation of the next expiry on a CPU.
Separate the reprogramming evaluation from the NOHZ idle evaluation which
needs to exclude the NOHZ timer to keep the reprogramming path lean and
clean.
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
---
ker... | {
"author": "Thomas Gleixner <tglx@kernel.org>",
"date": "Tue, 24 Feb 2026 17:38:33 +0100",
"is_openbsd": false,
"thread_id": "51f8535f-b98c-48e3-ba7b-f28759a92c16@arm.com.mbox.gz"
} |
lkml_critique | lkml | Peter recently posted a series tweaking the hrtimer subsystem to reduce the
overhead of the scheduler hrtick timer so it can be enabled by default:
https://lore.kernel.org/20260121162010.647043073@infradead.org
That turned out to be incomplete and led to a deeper investigation of the
related bits and pieces.
The ... | null | null | null | [patch 00/48] hrtimer,sched: General optimizations and hrtick
enablement | Replace the open coded container_of() orgy with a trivial
clock_base_next_timer() helper.
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
---
kernel/time/hrtimer.c | 19 ++++++++++---------
1 file changed, 10 insertions(+), 9 deletions(-)
--- a/kernel/time/hrtimer.c
+++ b/kernel/time/hrtimer.c
@@ -1933,6 +1933,13... | {
"author": "Thomas Gleixner <tglx@kernel.org>",
"date": "Tue, 24 Feb 2026 17:38:37 +0100",
"is_openbsd": false,
"thread_id": "51f8535f-b98c-48e3-ba7b-f28759a92c16@arm.com.mbox.gz"
} |
lkml_critique | lkml | Peter recently posted a series tweaking the hrtimer subsystem to reduce the
overhead of the scheduler hrtick timer so it can be enabled by default:
https://lore.kernel.org/20260121162010.647043073@infradead.org
That turned out to be incomplete and led to a deeper investigation of the
related bits and pieces.
The ... | null | null | null | [patch 00/48] hrtimer,sched: General optimizations and hrtick
enablement | Give the compiler some help to emit way better code.
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
---
kernel/time/hrtimer.c | 20 ++++----------------
1 file changed, 4 insertions(+), 16 deletions(-)
--- a/kernel/time/hrtimer.c
+++ b/kernel/time/hrtimer.c
@@ -529,22 +529,10 @@ static inline void debug_activate... | {
"author": "Thomas Gleixner <tglx@kernel.org>",
"date": "Tue, 24 Feb 2026 17:38:42 +0100",
"is_openbsd": false,
"thread_id": "51f8535f-b98c-48e3-ba7b-f28759a92c16@arm.com.mbox.gz"
} |
lkml_critique | lkml | Peter recently posted a series tweaking the hrtimer subsystem to reduce the
overhead of the scheduler hrtick timer so it can be enabled by default:
https://lore.kernel.org/20260121162010.647043073@infradead.org
That turned out to be incomplete and led to a deeper investigation of the
related bits and pieces.
The ... | null | null | null | [patch 00/48] hrtimer,sched: General optimizations and hrtick
enablement | Some RB tree users require quick access to the next and the previous node,
e.g. to check whether a modification of the node results in a change of the
nodes position in the tree. If the node position does not change, then the
modification can happen in place without going through a full enqueue
requeue cycle. A upcomin... | {
"author": "Thomas Gleixner <tglx@kernel.org>",
"date": "Tue, 24 Feb 2026 17:38:47 +0100",
"is_openbsd": false,
"thread_id": "51f8535f-b98c-48e3-ba7b-f28759a92c16@arm.com.mbox.gz"
} |
lkml_critique | lkml | Peter recently posted a series tweaking the hrtimer subsystem to reduce the
overhead of the scheduler hrtick timer so it can be enabled by default:
https://lore.kernel.org/20260121162010.647043073@infradead.org
That turned out to be incomplete and led to a deeper investigation of the
related bits and pieces.
The ... | null | null | null | [patch 00/48] hrtimer,sched: General optimizations and hrtick
enablement | The hrtimer subsystem wants to peak ahead to the next and previous timer to
evaluated whether a to be rearmed timer can stay at the same position in
the RB tree with the new expiry time.
The linked RB tree provides the infrastructure for this as it maintains
links to the previous and next nodes for each entry in the t... | {
"author": "Thomas Gleixner <tglx@kernel.org>",
"date": "Tue, 24 Feb 2026 17:38:52 +0100",
"is_openbsd": false,
"thread_id": "51f8535f-b98c-48e3-ba7b-f28759a92c16@arm.com.mbox.gz"
} |
lkml_critique | lkml | Peter recently posted a series tweaking the hrtimer subsystem to reduce the
overhead of the scheduler hrtick timer so it can be enabled by default:
https://lore.kernel.org/20260121162010.647043073@infradead.org
That turned out to be incomplete and led to a deeper investigation of the
related bits and pieces.
The ... | null | null | null | [patch 00/48] hrtimer,sched: General optimizations and hrtick
enablement | To prepare for optimizing the rearming of enqueued timers, switch to the
linked timerqueue. That allows to check whether the new expiry time changes
the position of the timer in the RB tree or not, by checking the new expiry
time against the previous and the next timers expiry.
Signed-off-by: Thomas Gleixner <tglx@ker... | {
"author": "Thomas Gleixner <tglx@kernel.org>",
"date": "Tue, 24 Feb 2026 17:38:57 +0100",
"is_openbsd": false,
"thread_id": "51f8535f-b98c-48e3-ba7b-f28759a92c16@arm.com.mbox.gz"
} |
lkml_critique | lkml | Peter recently posted a series tweaking the hrtimer subsystem to reduce the
overhead of the scheduler hrtick timer so it can be enabled by default:
https://lore.kernel.org/20260121162010.647043073@infradead.org
That turned out to be incomplete and led to a deeper investigation of the
related bits and pieces.
The ... | null | null | null | [patch 00/48] hrtimer,sched: General optimizations and hrtick
enablement | When modifying the expiry of a armed timer it is first dequeued, then the
expiry value is updated and then it is queued again.
This can be avoided when the new expiry value is within the range of the
previous and the next timer as that does not change the position in the RB
tree.
The linked timerqueue allows to peak ... | {
"author": "Thomas Gleixner <tglx@kernel.org>",
"date": "Tue, 24 Feb 2026 17:39:02 +0100",
"is_openbsd": false,
"thread_id": "51f8535f-b98c-48e3-ba7b-f28759a92c16@arm.com.mbox.gz"
} |
lkml_critique | lkml | Peter recently posted a series tweaking the hrtimer subsystem to reduce the
overhead of the scheduler hrtick timer so it can be enabled by default:
https://lore.kernel.org/20260121162010.647043073@infradead.org
That turned out to be incomplete and led to a deeper investigation of the
related bits and pieces.
The ... | null | null | null | [patch 00/48] hrtimer,sched: General optimizations and hrtick
enablement | From: Peter Zijlstra <peterz@infradead.org>
The deferred rearm of the clock event device after an interrupt and and
other hrtimer optimizations allow now to enable HRTICK for generic entry
architectures.
This decouples preemption from CONFIG_HZ, leaving only the periodic
load-balancer and various accounting things re... | {
"author": "Thomas Gleixner <tglx@kernel.org>",
"date": "Tue, 24 Feb 2026 17:39:08 +0100",
"is_openbsd": false,
"thread_id": "51f8535f-b98c-48e3-ba7b-f28759a92c16@arm.com.mbox.gz"
} |
lkml_critique | lkml | Peter recently posted a series tweaking the hrtimer subsystem to reduce the
overhead of the scheduler hrtick timer so it can be enabled by default:
https://lore.kernel.org/20260121162010.647043073@infradead.org
That turned out to be incomplete and led to a deeper investigation of the
related bits and pieces.
The ... | null | null | null | [patch 00/48] hrtimer,sched: General optimizations and hrtick
enablement | On Tue, Feb 24, 2026 at 05:35:12PM +0100, Thomas Gleixner wrote:
If you'd have added the shortlog, you'd have made nearly 350 lines :-)
Peter Zijlstra (11):
sched/eevdf: Fix HRTICK duration
hrtimer: Avoid pointless reprogramming in __hrtimer_start_range_ns()
hrtimer: Provide LAZY_REARM mode
s... | {
"author": "Peter Zijlstra <peterz@infradead.org>",
"date": "Wed, 25 Feb 2026 16:25:00 +0100",
"is_openbsd": false,
"thread_id": "51f8535f-b98c-48e3-ba7b-f28759a92c16@arm.com.mbox.gz"
} |
lkml_critique | lkml | Peter recently posted a series tweaking the hrtimer subsystem to reduce the
overhead of the scheduler hrtick timer so it can be enabled by default:
https://lore.kernel.org/20260121162010.647043073@infradead.org
That turned out to be incomplete and led to a deeper investigation of the
related bits and pieces.
The ... | null | null | null | [patch 00/48] hrtimer,sched: General optimizations and hrtick
enablement | On Wed, Feb 25 2026 at 16:25, Peter Zijlstra wrote:
I"d like to split them up and only pull the minimal stuff into the
subsystem branches. I made a plan already, but I can't find the notes
right now. I'll dig them out later.
Thanks,
tglx | {
"author": "Thomas Gleixner <tglx@kernel.org>",
"date": "Wed, 25 Feb 2026 17:02:27 +0100",
"is_openbsd": false,
"thread_id": "51f8535f-b98c-48e3-ba7b-f28759a92c16@arm.com.mbox.gz"
} |
lkml_critique | lkml | Peter recently posted a series tweaking the hrtimer subsystem to reduce the
overhead of the scheduler hrtick timer so it can be enabled by default:
https://lore.kernel.org/20260121162010.647043073@infradead.org
That turned out to be incomplete and led to a deeper investigation of the
related bits and pieces.
The ... | null | null | null | [patch 00/48] hrtimer,sched: General optimizations and hrtick
enablement | On 2/24/26 16:38, Thomas Gleixner wrote:
Should this also be EXIT_TO_USER_MODE_WORK_IRQ?
I guess it doesn't really matter for now (since arm64 doesn't have the generic entry
path and generic TIF bits yet and therefore HRTIMER_REARM_DEFERRED=n), but I've been
playing around with the this series, the generic entry serie... | {
"author": "Christian Loehle <christian.loehle@arm.com>",
"date": "Fri, 27 Feb 2026 15:57:55 +0000",
"is_openbsd": false,
"thread_id": "51f8535f-b98c-48e3-ba7b-f28759a92c16@arm.com.mbox.gz"
} |
lkml_critique | lkml | From: Markus Elfring <elfring@users.sourceforge.net>
Date: Fri, 27 Feb 2026 10:16:50 +0100
Use an additional label so that a bit of common code can be better reused
at the end of this function implementation.
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
---
drivers/i3c/master/dw-i3c-master.c | 7 +++... | null | null | null | [PATCH] i3c: dw: Use more common code in dw_i3c_master_i2c_xfers() | On Fri, Feb 27, 2026 at 11:20:59AM +0100, Markus Elfring wrote:
Reviewed-by: Frank Li <Frank.Li@nxp.com> | {
"author": "Frank Li <Frank.li@nxp.com>",
"date": "Fri, 27 Feb 2026 10:58:10 -0500",
"is_openbsd": false,
"thread_id": "aaG_El2oEFOwjn9l@lizhi-Precision-Tower-5810.mbox.gz"
} |
lkml_critique | lkml | Hi,
This series add support for SFPs ports available on the LAN966x PCI
device. In order to have the SFPs supported, additional devices are
needed such as clock controller and I2C.
As a reminder, the LAN966x PCI device driver use a device-tree overlay
to describe devices available on the PCI board. Adding support for... | null | null | null | [PATCH v5 00/28] lan966x pci device: Add support for SFPs | On Fri, Feb 27, 2026 at 02:54:04PM +0100, Herve Codina wrote:
Reviewed-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Thanks,
Charles | {
"author": "Charles Keepax <ckeepax@opensource.cirrus.com>",
"date": "Fri, 27 Feb 2026 15:57:51 +0000",
"is_openbsd": false,
"thread_id": "aaG%2FF3JKIpsefS5f@opensource.cirrus.com.mbox.gz"
} |
lkml_critique | lkml | Hi,
This series add support for SFPs ports available on the LAN966x PCI
device. In order to have the SFPs supported, additional devices are
needed such as clock controller and I2C.
As a reminder, the LAN966x PCI device driver use a device-tree overlay
to describe devices available on the PCI board. Adding support for... | null | null | null | [PATCH v5 00/28] lan966x pci device: Add support for SFPs | On Fri, Feb 27, 2026 at 02:54:06PM +0100, Herve Codina wrote:
Reviewed-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Thanks,
Charles | {
"author": "Charles Keepax <ckeepax@opensource.cirrus.com>",
"date": "Fri, 27 Feb 2026 15:58:15 +0000",
"is_openbsd": false,
"thread_id": "aaG%2FF3JKIpsefS5f@opensource.cirrus.com.mbox.gz"
} |
lkml_critique | lkml | There are some clocks where the rounding is managed by the hardware, and
the determine_rate() clk ops is just a noop that simply returns 0. Based
on discussions with Stephen at Linux Plumbers Conference, he suggested
adding a flag for this particular case. So let's add a new flag, and
update the clk core so that the de... | null | null | null | [PATCH 00/13] clk: add new flag CLK_ROUNDING_FW_MANAGED | Hi Brian,
We plan to fill out the determine rate later, as it can return error.
I guess, maybe we could use CLK_ROUNDING_NOOP, till we have proper .determine_rate() for this driver???
Cheers,
Biju | {
"author": "Biju Das <biju.das.jz@bp.renesas.com>",
"date": "Fri, 27 Feb 2026 15:57:28 +0000",
"is_openbsd": false,
"thread_id": "TY3PR01MB1134626136D6AE06C9A699F798673A@TY3PR01MB11346.jpnprd01.prod.outlook.com.mbox.gz"
} |
lkml_critique | lkml | There are some clocks where the rounding is managed by the hardware, and
the determine_rate() clk ops is just a noop that simply returns 0. Based
on discussions with Stephen at Linux Plumbers Conference, he suggested
adding a flag for this particular case. So let's add a new flag, and
update the clk core so that the de... | null | null | null | [PATCH 00/13] clk: add new flag CLK_ROUNDING_FW_MANAGED | On Fri, Feb 27, 2026 at 03:57:28PM +0000, Biju Das wrote:
OK, if you are planning to fill out the determine rate, then I'll just
skip over this driver to avoid the code churn.
Brian | {
"author": "Brian Masney <bmasney@redhat.com>",
"date": "Fri, 27 Feb 2026 11:01:12 -0500",
"is_openbsd": false,
"thread_id": "TY3PR01MB1134626136D6AE06C9A699F798673A@TY3PR01MB11346.jpnprd01.prod.outlook.com.mbox.gz"
} |
lkml_critique | netdev | From: Jiayuan Chen <jiayuan.chen@shopee.com>
bond_rr_gen_slave_id() dereferences bond->rr_tx_counter without a NULL
check. rr_tx_counter is a per-CPU counter only allocated in bond_open()
when the bond mode is round-robin. If the bond device was never brought
up, rr_tx_counter remains NULL, causing a null-ptr-deref.
... | null | null | null | [PATCH net v2 1/2] bonding: fix null-ptr-deref in bond_rr_gen_slave_id() | syzkaller reported a kernel panic [1] with the following crash stack:
Call Trace:
BUG: unable to handle page fault for address: ffff8ebd08580000
PF: supervisor write access in kernel mode
PF: error_code(0x0002) - not-present page
PGD 11f201067 P4D 11f201067 PUD 0
Oops: Oops: 0002 [#1] SMP PTI
CPU: 2 UID: 0 PID: 451 Co... | {
"author": "Jiayuan Chen <jiayuan.chen@linux.dev>",
"date": "Fri, 27 Feb 2026 17:22:48 +0800",
"is_openbsd": false,
"thread_id": "faed6bde8e7a96021bc9d55176b764c592f6ce08@linux.dev.mbox.gz"
} |
lkml_critique | netdev | From: Jiayuan Chen <jiayuan.chen@shopee.com>
bond_rr_gen_slave_id() dereferences bond->rr_tx_counter without a NULL
check. rr_tx_counter is a per-CPU counter only allocated in bond_open()
when the bond mode is round-robin. If the bond device was never brought
up, rr_tx_counter remains NULL, causing a null-ptr-deref.
... | null | null | null | [PATCH net v2 1/2] bonding: fix null-ptr-deref in bond_rr_gen_slave_id() | From: Jiayuan Chen <jiayuan.chen@shopee.com>
Add a selftest that reproduces the null-ptr-deref in
bond_rr_gen_slave_id() when XDP redirect targets a bond device in
round-robin mode that was never brought up. The test verifies the fix
by ensuring no crash occurs.
Test setup:
- bond0: active-backup mode, UP, with nativ... | {
"author": "Jiayuan Chen <jiayuan.chen@linux.dev>",
"date": "Fri, 27 Feb 2026 17:22:50 +0800",
"is_openbsd": false,
"thread_id": "faed6bde8e7a96021bc9d55176b764c592f6ce08@linux.dev.mbox.gz"
} |
lkml_critique | netdev | From: Jiayuan Chen <jiayuan.chen@shopee.com>
bond_rr_gen_slave_id() dereferences bond->rr_tx_counter without a NULL
check. rr_tx_counter is a per-CPU counter only allocated in bond_open()
when the bond mode is round-robin. If the bond device was never brought
up, rr_tx_counter remains NULL, causing a null-ptr-deref.
... | null | null | null | [PATCH net v2 1/2] bonding: fix null-ptr-deref in bond_rr_gen_slave_id() | On 2026-02-27 17:22:49 [+0800], Jiayuan Chen wrote:
Wouldn't it be better to put into bond_init()?
I haven't look into it but when can the bond_mode be changed?
Sebastian | {
"author": "Sebastian Andrzej Siewior <bigeasy@linutronix.de>",
"date": "Fri, 27 Feb 2026 10:45:58 +0100",
"is_openbsd": false,
"thread_id": "faed6bde8e7a96021bc9d55176b764c592f6ce08@linux.dev.mbox.gz"
} |
lkml_critique | netdev | From: Jiayuan Chen <jiayuan.chen@shopee.com>
bond_rr_gen_slave_id() dereferences bond->rr_tx_counter without a NULL
check. rr_tx_counter is a per-CPU counter only allocated in bond_open()
when the bond mode is round-robin. If the bond device was never brought
up, rr_tx_counter remains NULL, causing a null-ptr-deref.
... | null | null | null | [PATCH net v2 1/2] bonding: fix null-ptr-deref in bond_rr_gen_slave_id() | 2026/2/27 17:45, "Sebastian Andrzej Siewior" <bigeasy@linutronix.de mailto:bigeasy@linutronix.de?to=%22Sebastian%20Andrzej%20Siewior%22%20%3Cbigeasy%40linutronix.de%3E > wrote:
Thanks! bond_init() (ndo_init) is indeed a better fit, it is called by register_netdevice()
and naturally covers both bond_create() and bond... | {
"author": "\"Jiayuan Chen\" <jiayuan.chen@linux.dev>",
"date": "Fri, 27 Feb 2026 10:17:29 +0000",
"is_openbsd": false,
"thread_id": "faed6bde8e7a96021bc9d55176b764c592f6ce08@linux.dev.mbox.gz"
} |
lkml_critique | netdev | From: Jiayuan Chen <jiayuan.chen@shopee.com>
bond_rr_gen_slave_id() dereferences bond->rr_tx_counter without a NULL
check. rr_tx_counter is a per-CPU counter only allocated in bond_open()
when the bond mode is round-robin. If the bond device was never brought
up, rr_tx_counter remains NULL, causing a null-ptr-deref.
... | null | null | null | [PATCH net v2 1/2] bonding: fix null-ptr-deref in bond_rr_gen_slave_id() | On 2026-02-27 10:17:29 [+0000], Jiayuan Chen wrote:
Must the device be in down state or can this be also changed while the
device is up?
Sebastian | {
"author": "Sebastian Andrzej Siewior <bigeasy@linutronix.de>",
"date": "Fri, 27 Feb 2026 11:21:49 +0100",
"is_openbsd": false,
"thread_id": "faed6bde8e7a96021bc9d55176b764c592f6ce08@linux.dev.mbox.gz"
} |
lkml_critique | netdev | From: Jiayuan Chen <jiayuan.chen@shopee.com>
bond_rr_gen_slave_id() dereferences bond->rr_tx_counter without a NULL
check. rr_tx_counter is a per-CPU counter only allocated in bond_open()
when the bond mode is round-robin. If the bond device was never brought
up, rr_tx_counter remains NULL, causing a null-ptr-deref.
... | null | null | null | [PATCH net v2 1/2] bonding: fix null-ptr-deref in bond_rr_gen_slave_id() | February 27, 2026 at 18:21, "Sebastian Andrzej Siewior" <bigeasy@linutronix.de mailto:bigeasy@linutronix.de?to=%22Sebastian%20Andrzej%20Siewior%22%20%3Cbigeasy%40linutronix.de%3E > wrote:
The mode change requires the device to be DOWN. BOND_OPT_MODE is defined with BOND_OPTFLAG_IFDOWN,
and bond_opt_check_flags() enf... | {
"author": "\"Jiayuan Chen\" <jiayuan.chen@linux.dev>",
"date": "Fri, 27 Feb 2026 10:37:53 +0000",
"is_openbsd": false,
"thread_id": "faed6bde8e7a96021bc9d55176b764c592f6ce08@linux.dev.mbox.gz"
} |
lkml_critique | netdev | Set MACB_CAPS_EEE for the Raspberry Pi 5 RP1 southbridge
(Cadence GEM_GXL rev 0x00070109 paired with BCM54213PE PHY).
EEE has been verified on RP1 hardware: the LPI counter registers
at 0x270-0x27c return valid data, the TXLPIEN bit in NCR (bit 19)
controls LPI transmission correctly, and ethtool --show-eee reports
th... | null | null | null | [PATCH net-next v5 4/5] net: cadence: macb: enable EEE for Raspberry Pi RP1 | The GEM MAC provides four read-only, clear-on-read LPI statistics
registers at offsets 0x270-0x27c:
GEM_RXLPI (0x270): RX LPI transition count (16-bit)
GEM_RXLPITIME (0x274): cumulative RX LPI time (24-bit)
GEM_TXLPI (0x278): TX LPI transition count (16-bit)
GEM_TXLPITIME (0x27c): cumulative TX LPI tim... | {
"author": "Nicolai Buchwitz <nb@tipi-net.de>",
"date": "Fri, 27 Feb 2026 16:06:06 +0100",
"is_openbsd": false,
"thread_id": "20260227150610.242215-3-nb@tipi-net.de.mbox.gz"
} |
lkml_critique | netdev | Set MACB_CAPS_EEE for the Raspberry Pi 5 RP1 southbridge
(Cadence GEM_GXL rev 0x00070109 paired with BCM54213PE PHY).
EEE has been verified on RP1 hardware: the LPI counter registers
at 0x270-0x27c return valid data, the TXLPIEN bit in NCR (bit 19)
controls LPI transmission correctly, and ethtool --show-eee reports
th... | null | null | null | [PATCH net-next v5 4/5] net: cadence: macb: enable EEE for Raspberry Pi RP1 | The GEM MAC has hardware LPI registers (NCR bit 19: TXLPIEN) but no
built-in idle timer, so asserting TXLPIEN blocks all TX immediately
with no automatic wake. A software idle timer is required, as noted
in Microchip documentation (section 40.6.19): "It is best to use
firmware to control LPI."
Implement phylink manage... | {
"author": "Nicolai Buchwitz <nb@tipi-net.de>",
"date": "Fri, 27 Feb 2026 16:06:07 +0100",
"is_openbsd": false,
"thread_id": "20260227150610.242215-3-nb@tipi-net.de.mbox.gz"
} |
lkml_critique | netdev | Set MACB_CAPS_EEE for the Raspberry Pi 5 RP1 southbridge
(Cadence GEM_GXL rev 0x00070109 paired with BCM54213PE PHY).
EEE has been verified on RP1 hardware: the LPI counter registers
at 0x270-0x27c return valid data, the TXLPIEN bit in NCR (bit 19)
controls LPI transmission correctly, and ethtool --show-eee reports
th... | null | null | null | [PATCH net-next v5 4/5] net: cadence: macb: enable EEE for Raspberry Pi RP1 | Add Energy Efficient Ethernet (IEEE 802.3az) support to the Cadence GEM
(macb) driver using phylink's managed EEE framework. The GEM MAC has
hardware LPI registers but no built-in idle timer, so the driver
implements software-managed TX LPI using a delayed_work timer while
delegating EEE negotiation and ethtool state t... | {
"author": "Nicolai Buchwitz <nb@tipi-net.de>",
"date": "Fri, 27 Feb 2026 16:06:05 +0100",
"is_openbsd": false,
"thread_id": "20260227150610.242215-3-nb@tipi-net.de.mbox.gz"
} |
lkml_critique | netdev | Set MACB_CAPS_EEE for the Raspberry Pi 5 RP1 southbridge
(Cadence GEM_GXL rev 0x00070109 paired with BCM54213PE PHY).
EEE has been verified on RP1 hardware: the LPI counter registers
at 0x270-0x27c return valid data, the TXLPIEN bit in NCR (bit 19)
controls LPI transmission correctly, and ethtool --show-eee reports
th... | null | null | null | [PATCH net-next v5 4/5] net: cadence: macb: enable EEE for Raspberry Pi RP1 | Implement get_eee and set_eee ethtool ops for GEM as simple passthroughs
to phylink_ethtool_get_eee() and phylink_ethtool_set_eee().
No MACB_CAPS_EEE guard is needed: phylink returns -EOPNOTSUPP from both
ops when mac_supports_eee is false, which is the case when
lpi_capabilities and lpi_interfaces are not populated. ... | {
"author": "Nicolai Buchwitz <nb@tipi-net.de>",
"date": "Fri, 27 Feb 2026 16:06:08 +0100",
"is_openbsd": false,
"thread_id": "20260227150610.242215-3-nb@tipi-net.de.mbox.gz"
} |
lkml_critique | netdev | Set MACB_CAPS_EEE for the Raspberry Pi 5 RP1 southbridge
(Cadence GEM_GXL rev 0x00070109 paired with BCM54213PE PHY).
EEE has been verified on RP1 hardware: the LPI counter registers
at 0x270-0x27c return valid data, the TXLPIEN bit in NCR (bit 19)
controls LPI transmission correctly, and ethtool --show-eee reports
th... | null | null | null | [PATCH net-next v5 4/5] net: cadence: macb: enable EEE for Raspberry Pi RP1 | Set MACB_CAPS_EEE for the Mobileye EyeQ5 GEM instance. EEE has been
verified on EyeQ5 hardware using a loopback setup with ethtool
--show-eee confirming EEE active on both ends at 100baseT/Full and
1000baseT/Full.
Tested-by: Théo Lebrun <theo.lebrun@bootlin.com>
Signed-off-by: Nicolai Buchwitz <nb@tipi-net.de>
---
dr... | {
"author": "Nicolai Buchwitz <nb@tipi-net.de>",
"date": "Fri, 27 Feb 2026 16:06:10 +0100",
"is_openbsd": false,
"thread_id": "20260227150610.242215-3-nb@tipi-net.de.mbox.gz"
} |
lkml_critique | netdev | Hi,
In bnge_hwrm_func_resc_qcaps() we read the firmware-reported value:
hw_resc->max_hw_ring_grps =
le16_to_cpu(resp->max_hw_ring_grps);
but later overwrite it with:
hw_resc->max_hw_ring_grps = hw_resc->max_rx_rings;
This effectively discards the firmware capability and assumes
max_hw_ring_grps == max_rx_r... | null | null | null | [query] about max_hw_ring_grps override in bnge_hwrm_func_resc_qcaps() | On Thu, Feb 26, 2026 at 5:45 PM Alok Tiwari <alok.a.tiwari@oracle.com> wrote:
Thanks for pointing this out.
Yes, this is intentional.
max_hw_ring_grps should be equal to max_rx_rings only.
We can remove hw_resc->max_hw_ring_grps = le16_to_cpu(resp->max_hw_ring_grps).
Older firmware versions used the max_hw_ring_grps f... | {
"author": "Vikas Gupta <vikas.gupta@broadcom.com>",
"date": "Fri, 27 Feb 2026 14:47:45 +0530",
"is_openbsd": false,
"thread_id": "CAHLZf_sCzu9WGQyD9sj1oBoJVcv7ha7PzhK_gWfqFaJF5eP9HA@mail.gmail.com.mbox.gz"
} |
lkml_critique | netdev | This series fixes two issues in the bonding 802.3ad implementation
related to port state management and churn detection:
1. When disabling a port, we need to set AD_RX_PORT_DISABLED to ensure
proper state machine transitions, preventing ports from getting stuck
in AD_RX_CURRENT state.
2. The ad_churn_machine im... | null | null | null | [PATCHv3 net 0/3] bonding: fix 802.3ad churn machine and port state issues | When disabling a port’s collecting and distributing states, updating only
rx_disabled is not sufficient. We also need to set AD_RX_PORT_DISABLED
so that the rx_machine transitions into the AD_RX_EXPIRED state.
One example is in ad_agg_selection_logic(): when a new aggregator is
selected and old active aggregator is di... | {
"author": "Hangbin Liu <liuhangbin@gmail.com>",
"date": "Thu, 26 Feb 2026 12:53:28 +0000",
"is_openbsd": false,
"thread_id": "aaE32DlfrX9S5KNT@fedora.mbox.gz"
} |
lkml_critique | netdev | This series fixes two issues in the bonding 802.3ad implementation
related to port state management and churn detection:
1. When disabling a port, we need to set AD_RX_PORT_DISABLED to ensure
proper state machine transitions, preventing ports from getting stuck
in AD_RX_CURRENT state.
2. The ad_churn_machine im... | null | null | null | [PATCHv3 net 0/3] bonding: fix 802.3ad churn machine and port state issues | The current ad_churn_machine implementation only transitions the
actor/partner churn state to churned or none after the churn timer expires.
However, IEEE 802.1AX-2014 specifies that a port should enter the none
state immediately once the actor’s port state enters synchronization.
Another issue is that if the churn ti... | {
"author": "Hangbin Liu <liuhangbin@gmail.com>",
"date": "Thu, 26 Feb 2026 12:53:29 +0000",
"is_openbsd": false,
"thread_id": "aaE32DlfrX9S5KNT@fedora.mbox.gz"
} |
lkml_critique | netdev | This series fixes two issues in the bonding 802.3ad implementation
related to port state management and churn detection:
1. When disabling a port, we need to set AD_RX_PORT_DISABLED to ensure
proper state machine transitions, preventing ports from getting stuck
in AD_RX_CURRENT state.
2. The ad_churn_machine im... | null | null | null | [PATCHv3 net 0/3] bonding: fix 802.3ad churn machine and port state issues | Rename the current LACP priority test to LACP ad_select testing, and
extend it to include validation of the actor state machine and churn
state logic. The updated tests verify that both the mux state machine and
the churn state machine behave correctly under aggregator selection and
failover scenarios.
Signed-off-by: ... | {
"author": "Hangbin Liu <liuhangbin@gmail.com>",
"date": "Thu, 26 Feb 2026 12:53:30 +0000",
"is_openbsd": false,
"thread_id": "aaE32DlfrX9S5KNT@fedora.mbox.gz"
} |
lkml_critique | netdev | This series fixes two issues in the bonding 802.3ad implementation
related to port state management and churn detection:
1. When disabling a port, we need to set AD_RX_PORT_DISABLED to ensure
proper state machine transitions, preventing ports from getting stuck
in AD_RX_CURRENT state.
2. The ad_churn_machine im... | null | null | null | [PATCHv3 net 0/3] bonding: fix 802.3ad churn machine and port state issues | Hangbin Liu <liuhangbin@gmail.com> wrote:
I missed this last time it was posted, but reading it now I
think the functional change looks good, but I question the usefulness of
including the 25 line ASCII art version of the state diagram.
The standard is publicly available, so a comment saying that the
state machine... | {
"author": "Jay Vosburgh <jv@jvosburgh.net>",
"date": "Thu, 26 Feb 2026 16:36:46 -0800",
"is_openbsd": false,
"thread_id": "aaE32DlfrX9S5KNT@fedora.mbox.gz"
} |
lkml_critique | netdev | This series fixes two issues in the bonding 802.3ad implementation
related to port state management and churn detection:
1. When disabling a port, we need to set AD_RX_PORT_DISABLED to ensure
proper state machine transitions, preventing ports from getting stuck
in AD_RX_CURRENT state.
2. The ad_churn_machine im... | null | null | null | [PATCHv3 net 0/3] bonding: fix 802.3ad churn machine and port state issues | On Thu, Feb 26, 2026 at 04:36:46PM -0800, Jay Vosburgh wrote:
I added it here to help new readers and reviewers understand the logic
quickly. If you think there’s no need to include it in the code, maybe
we can move it to the commit description?
Thanks
Hangbin | {
"author": "Hangbin Liu <liuhangbin@gmail.com>",
"date": "Fri, 27 Feb 2026 00:52:54 +0000",
"is_openbsd": false,
"thread_id": "aaE32DlfrX9S5KNT@fedora.mbox.gz"
} |
lkml_critique | netdev | This series fixes two issues in the bonding 802.3ad implementation
related to port state management and churn detection:
1. When disabling a port, we need to set AD_RX_PORT_DISABLED to ensure
proper state machine transitions, preventing ports from getting stuck
in AD_RX_CURRENT state.
2. The ad_churn_machine im... | null | null | null | [PATCHv3 net 0/3] bonding: fix 802.3ad churn machine and port state issues | Hangbin Liu <liuhangbin@gmail.com> wrote:
I'm not sure I'm seeing the problem here, is there an actual
misbehavior being fixed here? The port is receiving LACPDUs, and from
the receive state machine point of view (Figure 6-18) there's no issue.
The "port_enabled" variable (6.4.7) also informs the state machine
beha... | {
"author": "Jay Vosburgh <jv@jvosburgh.net>",
"date": "Thu, 26 Feb 2026 17:16:55 -0800",
"is_openbsd": false,
"thread_id": "aaE32DlfrX9S5KNT@fedora.mbox.gz"
} |
lkml_critique | netdev | This series fixes two issues in the bonding 802.3ad implementation
related to port state management and churn detection:
1. When disabling a port, we need to set AD_RX_PORT_DISABLED to ensure
proper state machine transitions, preventing ports from getting stuck
in AD_RX_CURRENT state.
2. The ad_churn_machine im... | null | null | null | [PATCHv3 net 0/3] bonding: fix 802.3ad churn machine and port state issues | Hangbin Liu <liuhangbin@gmail.com> wrote:
Personally, I'd leave it out, and just put a reference.
The churn machine isn't that critical, even the standards
committee didn't like it and removed it from the 2020 edition of
802.1AX.
Still, whatever we provide should work in accordance with the
2014 standard we're n... | {
"author": "Jay Vosburgh <jv@jvosburgh.net>",
"date": "Thu, 26 Feb 2026 17:42:13 -0800",
"is_openbsd": false,
"thread_id": "aaE32DlfrX9S5KNT@fedora.mbox.gz"
} |
lkml_critique | netdev | This series fixes two issues in the bonding 802.3ad implementation
related to port state management and churn detection:
1. When disabling a port, we need to set AD_RX_PORT_DISABLED to ensure
proper state machine transitions, preventing ports from getting stuck
in AD_RX_CURRENT state.
2. The ad_churn_machine im... | null | null | null | [PATCHv3 net 0/3] bonding: fix 802.3ad churn machine and port state issues | On Thu, Feb 26, 2026 at 05:16:55PM -0800, Jay Vosburgh wrote:
Yes, the reason I do it here is we select another aggregator and called
__disable_port() for the old one. If we don't update sm_rx_state, the port
will be keep in collecting/distributing state, and the partner will also
keep in the c/d state.
Here we enter... | {
"author": "Hangbin Liu <liuhangbin@gmail.com>",
"date": "Fri, 27 Feb 2026 02:31:05 +0000",
"is_openbsd": false,
"thread_id": "aaE32DlfrX9S5KNT@fedora.mbox.gz"
} |
lkml_critique | netdev | This series fixes two issues in the bonding 802.3ad implementation
related to port state management and churn detection:
1. When disabling a port, we need to set AD_RX_PORT_DISABLED to ensure
proper state machine transitions, preventing ports from getting stuck
in AD_RX_CURRENT state.
2. The ad_churn_machine im... | null | null | null | [PATCHv3 net 0/3] bonding: fix 802.3ad churn machine and port state issues | On Thu, Feb 26, 2026 at 05:42:13PM -0800, Jay Vosburgh wrote:
Oh, I didn't notice this. I posted a patch[1] to net-next to export the
churn state via netlink recently. Should I revert this patch?
Got it, I will remove it.
[1] http://lore.kernel.org/netdev/20260224020215.6012-1-liuhangbin@gmail.com
Thanks
Hangbin | {
"author": "Hangbin Liu <liuhangbin@gmail.com>",
"date": "Fri, 27 Feb 2026 02:36:31 +0000",
"is_openbsd": false,
"thread_id": "aaE32DlfrX9S5KNT@fedora.mbox.gz"
} |
lkml_critique | netdev | This series fixes two issues in the bonding 802.3ad implementation
related to port state management and churn detection:
1. When disabling a port, we need to set AD_RX_PORT_DISABLED to ensure
proper state machine transitions, preventing ports from getting stuck
in AD_RX_CURRENT state.
2. The ad_churn_machine im... | null | null | null | [PATCHv3 net 0/3] bonding: fix 802.3ad churn machine and port state issues | On Fri, Feb 27, 2026 at 02:31:05AM +0000, Hangbin Liu wrote:
I did a test and the failover takes about 200ms with the environment in patch 03.
Here is the full log
Code: the timer count starts after the old active port link down.
```
ip -n "${c_ns}" link set eth1 down
date +'%F %T.%3N'
ip -n ${c_ns} -d link show eth... | {
"author": "Hangbin Liu <liuhangbin@gmail.com>",
"date": "Fri, 27 Feb 2026 04:14:45 +0000",
"is_openbsd": false,
"thread_id": "aaE32DlfrX9S5KNT@fedora.mbox.gz"
} |
lkml_critique | netdev | This series fixes two issues in the bonding 802.3ad implementation
related to port state management and churn detection:
1. When disabling a port, we need to set AD_RX_PORT_DISABLED to ensure
proper state machine transitions, preventing ports from getting stuck
in AD_RX_CURRENT state.
2. The ad_churn_machine im... | null | null | null | [PATCHv3 net 0/3] bonding: fix 802.3ad churn machine and port state issues | Hangbin Liu <liuhangbin@gmail.com> wrote:
"disable" the port here really means from bonding's perspective,
so, generally equivalent to the backup interface of an active-backup
mode bond.
Such a backup interface is typically carrier up and able to send
or receive packets. The peer generally won't send packets to t... | {
"author": "Jay Vosburgh <jv@jvosburgh.net>",
"date": "Thu, 26 Feb 2026 20:42:27 -0800",
"is_openbsd": false,
"thread_id": "aaE32DlfrX9S5KNT@fedora.mbox.gz"
} |
lkml_critique | netdev | This series fixes two issues in the bonding 802.3ad implementation
related to port state management and churn detection:
1. When disabling a port, we need to set AD_RX_PORT_DISABLED to ensure
proper state machine transitions, preventing ports from getting stuck
in AD_RX_CURRENT state.
2. The ad_churn_machine im... | null | null | null | [PATCHv3 net 0/3] bonding: fix 802.3ad churn machine and port state issues | On Thu, Feb 26, 2026 at 08:42:27PM -0800, Jay Vosburgh wrote:
Oh, got it.
OK, this makes sense to me.
^^ I mean with LACPDU exchange..
In theory this looks good. But in fact, when we do failover and set the
previous active port to disabled via
- __disable_port(port)
- slave->rx_disab... | {
"author": "Hangbin Liu <liuhangbin@gmail.com>",
"date": "Fri, 27 Feb 2026 06:21:12 +0000",
"is_openbsd": false,
"thread_id": "aaE32DlfrX9S5KNT@fedora.mbox.gz"
} |
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