source large_stringclasses 2
values | subject large_stringclasses 112
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lkml | [PATCH v4 00/13] Enable I2C on SA8255p Qualcomm platforms | The Qualcomm automotive SA8255p SoC relies on firmware to configure
platform resources, including clocks, interconnects and TLMM.
The driver requests resources operations over SCMI using power
and performance protocols.
The SCMI power protocol enables or disables resources like clocks,
interconnect paths, and TLMM (GP... | The GENI Serial Engine drivers (I2C, SPI, and SERIAL) currently handle
the attachment of power domains. This often leads to duplicated code
logic across different driver probe functions.
Introduce a new helper API, geni_se_domain_attach(), to centralize
the logic for attaching "power" and "perf" domains to the GENI SE... | {
"author": "Praveen Talari <praveen.talari@oss.qualcomm.com>",
"date": "Mon, 2 Feb 2026 23:39:15 +0530",
"thread_id": "20260202180922.1692428-1-praveen.talari@oss.qualcomm.com.mbox.gz"
} |
lkml | [PATCH v4 00/13] Enable I2C on SA8255p Qualcomm platforms | The Qualcomm automotive SA8255p SoC relies on firmware to configure
platform resources, including clocks, interconnects and TLMM.
The driver requests resources operations over SCMI using power
and performance protocols.
The SCMI power protocol enables or disables resources like clocks,
interconnect paths, and TLMM (GP... | The GENI Serial Engine (SE) drivers (I2C, SPI, and SERIAL) currently
manage performance levels and operating points directly. This resulting
in code duplication across drivers. such as configuring a specific level
or find and apply an OPP based on a clock frequency.
Introduce two new helper APIs, geni_se_set_perf_leve... | {
"author": "Praveen Talari <praveen.talari@oss.qualcomm.com>",
"date": "Mon, 2 Feb 2026 23:39:16 +0530",
"thread_id": "20260202180922.1692428-1-praveen.talari@oss.qualcomm.com.mbox.gz"
} |
lkml | [PATCH v4 00/13] Enable I2C on SA8255p Qualcomm platforms | The Qualcomm automotive SA8255p SoC relies on firmware to configure
platform resources, including clocks, interconnects and TLMM.
The driver requests resources operations over SCMI using power
and performance protocols.
The SCMI power protocol enables or disables resources like clocks,
interconnect paths, and TLMM (GP... | Add DT bindings for the QUP GENI I2C controller on sa8255p platforms.
SA8255p platform abstracts resources such as clocks, interconnect and
GPIO pins configuration in Firmware. SCMI power and perf protocol
are utilized to request resource configurations.
SA8255p platform does not require the Serial Engine (SE) common... | {
"author": "Praveen Talari <praveen.talari@oss.qualcomm.com>",
"date": "Mon, 2 Feb 2026 23:39:17 +0530",
"thread_id": "20260202180922.1692428-1-praveen.talari@oss.qualcomm.com.mbox.gz"
} |
lkml | [PATCH v4 00/13] Enable I2C on SA8255p Qualcomm platforms | The Qualcomm automotive SA8255p SoC relies on firmware to configure
platform resources, including clocks, interconnects and TLMM.
The driver requests resources operations over SCMI using power
and performance protocols.
The SCMI power protocol enables or disables resources like clocks,
interconnect paths, and TLMM (GP... | Moving the serial engine setup to geni_i2c_init() API for a cleaner
probe function and utilizes the PM runtime API to control resources
instead of direct clock-related APIs for better resource management.
Enables reusability of the serial engine initialization like
hibernation and deep sleep features where hardware co... | {
"author": "Praveen Talari <praveen.talari@oss.qualcomm.com>",
"date": "Mon, 2 Feb 2026 23:39:18 +0530",
"thread_id": "20260202180922.1692428-1-praveen.talari@oss.qualcomm.com.mbox.gz"
} |
lkml | [PATCH v4 00/13] Enable I2C on SA8255p Qualcomm platforms | The Qualcomm automotive SA8255p SoC relies on firmware to configure
platform resources, including clocks, interconnects and TLMM.
The driver requests resources operations over SCMI using power
and performance protocols.
The SCMI power protocol enables or disables resources like clocks,
interconnect paths, and TLMM (GP... | Refactor the resource initialization in geni_i2c_probe() by introducing
a new geni_i2c_resources_init() function and utilizing the common
geni_se_resources_init() framework and clock frequency mapping, making the
probe function cleaner.
Acked-by: Viken Dadhaniya <viken.dadhaniya@oss.qualcomm.com>
Signed-off-by: Pravee... | {
"author": "Praveen Talari <praveen.talari@oss.qualcomm.com>",
"date": "Mon, 2 Feb 2026 23:39:19 +0530",
"thread_id": "20260202180922.1692428-1-praveen.talari@oss.qualcomm.com.mbox.gz"
} |
lkml | [PATCH v4 00/13] Enable I2C on SA8255p Qualcomm platforms | The Qualcomm automotive SA8255p SoC relies on firmware to configure
platform resources, including clocks, interconnects and TLMM.
The driver requests resources operations over SCMI using power
and performance protocols.
The SCMI power protocol enables or disables resources like clocks,
interconnect paths, and TLMM (GP... | To manage GENI serial engine resources during runtime power management,
drivers currently need to call functions for ICC, clock, and
SE resource operations in both suspend and resume paths, resulting in
code duplication across drivers.
The new geni_se_resources_activate() and geni_se_resources_deactivate()
helper APIs... | {
"author": "Praveen Talari <praveen.talari@oss.qualcomm.com>",
"date": "Mon, 2 Feb 2026 23:39:20 +0530",
"thread_id": "20260202180922.1692428-1-praveen.talari@oss.qualcomm.com.mbox.gz"
} |
lkml | [PATCH v4 00/13] Enable I2C on SA8255p Qualcomm platforms | The Qualcomm automotive SA8255p SoC relies on firmware to configure
platform resources, including clocks, interconnects and TLMM.
The driver requests resources operations over SCMI using power
and performance protocols.
The SCMI power protocol enables or disables resources like clocks,
interconnect paths, and TLMM (GP... | To avoid repeatedly fetching and checking platform data across various
functions, store the struct of_device_id data directly in the i2c
private structure. This change enhances code maintainability and reduces
redundancy.
Acked-by: Viken Dadhaniya <viken.dadhaniya@oss.qualcomm.com>
Signed-off-by: Praveen Talari <prave... | {
"author": "Praveen Talari <praveen.talari@oss.qualcomm.com>",
"date": "Mon, 2 Feb 2026 23:39:21 +0530",
"thread_id": "20260202180922.1692428-1-praveen.talari@oss.qualcomm.com.mbox.gz"
} |
lkml | [PATCH v4 00/13] Enable I2C on SA8255p Qualcomm platforms | The Qualcomm automotive SA8255p SoC relies on firmware to configure
platform resources, including clocks, interconnects and TLMM.
The driver requests resources operations over SCMI using power
and performance protocols.
The SCMI power protocol enables or disables resources like clocks,
interconnect paths, and TLMM (GP... | The Qualcomm automotive SA8255p SoC relies on firmware to configure
platform resources, including clocks, interconnects and TLMM.
The driver requests resources operations over SCMI using power
and performance protocols.
The SCMI power protocol enables or disables resources like clocks,
interconnect paths, and TLMM (GP... | {
"author": "Praveen Talari <praveen.talari@oss.qualcomm.com>",
"date": "Mon, 2 Feb 2026 23:39:22 +0530",
"thread_id": "20260202180922.1692428-1-praveen.talari@oss.qualcomm.com.mbox.gz"
} |
lkml | [PATCH] mshv: Make MSHV mutually exclusive with KEXEC | The MSHV driver deposits kernel-allocated pages to the hypervisor during
runtime and never withdraws them. This creates a fundamental incompatibility
with KEXEC, as these deposited pages remain unavailable to the new kernel
loaded via KEXEC, leading to potential system crashes upon kernel accessing
hypervisor deposited... | On 1/23/2026 2:20 PM, Stanislav Kinsburskii wrote:
Reviewed-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> | {
"author": "Nuno Das Neves <nunodasneves@linux.microsoft.com>",
"date": "Fri, 23 Jan 2026 16:09:49 -0800",
"thread_id": "aYDUOeXIoOV4qtRk@skinsburskii.localdomain.mbox.gz"
} |
lkml | [PATCH] mshv: Make MSHV mutually exclusive with KEXEC | The MSHV driver deposits kernel-allocated pages to the hypervisor during
runtime and never withdraws them. This creates a fundamental incompatibility
with KEXEC, as these deposited pages remain unavailable to the new kernel
loaded via KEXEC, leading to potential system crashes upon kernel accessing
hypervisor deposited... | On 1/23/26 14:20, Stanislav Kinsburskii wrote:
Will this affect CRASH kexec? I see few CONFIG_CRASH_DUMP in kexec.c
implying that crash dump might be involved. Or did you test kdump
and it was fine?
Thanks,
-Mukesh | {
"author": "Mukesh R <mrathor@linux.microsoft.com>",
"date": "Fri, 23 Jan 2026 16:16:33 -0800",
"thread_id": "aYDUOeXIoOV4qtRk@skinsburskii.localdomain.mbox.gz"
} |
lkml | [PATCH] mshv: Make MSHV mutually exclusive with KEXEC | The MSHV driver deposits kernel-allocated pages to the hypervisor during
runtime and never withdraws them. This creates a fundamental incompatibility
with KEXEC, as these deposited pages remain unavailable to the new kernel
loaded via KEXEC, leading to potential system crashes upon kernel accessing
hypervisor deposited... | On Fri, Jan 23, 2026 at 04:16:33PM -0800, Mukesh R wrote:
Yes, it will. Crash kexec depends on normal kexec functionality, so it
will be affected as well.
Thanks,
Stanislav | {
"author": "Stanislav Kinsburskii <skinsburskii@linux.microsoft.com>",
"date": "Sun, 25 Jan 2026 14:39:26 -0800",
"thread_id": "aYDUOeXIoOV4qtRk@skinsburskii.localdomain.mbox.gz"
} |
lkml | [PATCH] mshv: Make MSHV mutually exclusive with KEXEC | The MSHV driver deposits kernel-allocated pages to the hypervisor during
runtime and never withdraws them. This creates a fundamental incompatibility
with KEXEC, as these deposited pages remain unavailable to the new kernel
loaded via KEXEC, leading to potential system crashes upon kernel accessing
hypervisor deposited... | On Fri, Jan 23, 2026 at 10:20:53PM +0000, Stanislav Kinsburskii wrote:
Someone might want to stop all guest VMs and do a kexec. Which is valid
and would work without any issue for L1VH.
Also, I don't think it is reasonable at all that someone needs to
disable basic kernel functionality such as kexec in order to use o... | {
"author": "Anirudh Rayabharam <anirudh@anirudhrb.com>",
"date": "Tue, 27 Jan 2026 00:19:24 +0530",
"thread_id": "aYDUOeXIoOV4qtRk@skinsburskii.localdomain.mbox.gz"
} |
lkml | [PATCH] mshv: Make MSHV mutually exclusive with KEXEC | The MSHV driver deposits kernel-allocated pages to the hypervisor during
runtime and never withdraws them. This creates a fundamental incompatibility
with KEXEC, as these deposited pages remain unavailable to the new kernel
loaded via KEXEC, leading to potential system crashes upon kernel accessing
hypervisor deposited... | On 1/25/26 14:39, Stanislav Kinsburskii wrote:
So not sure I understand the reason for this patch. We can just block
kexec if there are any VMs running, right? Doing this would mean any
further developement would be without a ver important and major feature,
right? | {
"author": "Mukesh R <mrathor@linux.microsoft.com>",
"date": "Mon, 26 Jan 2026 12:20:09 -0800",
"thread_id": "aYDUOeXIoOV4qtRk@skinsburskii.localdomain.mbox.gz"
} |
lkml | [PATCH] mshv: Make MSHV mutually exclusive with KEXEC | The MSHV driver deposits kernel-allocated pages to the hypervisor during
runtime and never withdraws them. This creates a fundamental incompatibility
with KEXEC, as these deposited pages remain unavailable to the new kernel
loaded via KEXEC, leading to potential system crashes upon kernel accessing
hypervisor deposited... | On Mon, Jan 26, 2026 at 12:20:09PM -0800, Mukesh R wrote:
This is an option. But until it's implemented and merged, a user mshv
driver gets into a situation where kexec is broken in a non-obvious way.
The system may crash at any time after kexec, depending on whether the
new kernel touches the pages deposited to hyper... | {
"author": "Stanislav Kinsburskii <skinsburskii@linux.microsoft.com>",
"date": "Mon, 26 Jan 2026 12:43:58 -0800",
"thread_id": "aYDUOeXIoOV4qtRk@skinsburskii.localdomain.mbox.gz"
} |
lkml | [PATCH] mshv: Make MSHV mutually exclusive with KEXEC | The MSHV driver deposits kernel-allocated pages to the hypervisor during
runtime and never withdraws them. This creates a fundamental incompatibility
with KEXEC, as these deposited pages remain unavailable to the new kernel
loaded via KEXEC, leading to potential system crashes upon kernel accessing
hypervisor deposited... | On Tue, Jan 27, 2026 at 12:19:24AM +0530, Anirudh Rayabharam wrote:
No, it won't work and hypervsisor depostied pages won't be withdrawn.
Also, kernel consisntency must no depend on use space behavior.
It's a temporary measure until proper page lifecycle management is
supported in the driver.
Mutual exclusion of th... | {
"author": "Stanislav Kinsburskii <skinsburskii@linux.microsoft.com>",
"date": "Mon, 26 Jan 2026 12:46:44 -0800",
"thread_id": "aYDUOeXIoOV4qtRk@skinsburskii.localdomain.mbox.gz"
} |
lkml | [PATCH] mshv: Make MSHV mutually exclusive with KEXEC | The MSHV driver deposits kernel-allocated pages to the hypervisor during
runtime and never withdraws them. This creates a fundamental incompatibility
with KEXEC, as these deposited pages remain unavailable to the new kernel
loaded via KEXEC, leading to potential system crashes upon kernel accessing
hypervisor deposited... | On 1/26/26 12:43, Stanislav Kinsburskii wrote:
I understand that. But with this we cannot collect core and debug any
crashes. I was thinking there would be a quick way to prohibit kexec
for update via notifier or some other quick hack. Did you already
explore that and didn't find anything, hence this?
Thanks,
-Mukesh | {
"author": "Mukesh R <mrathor@linux.microsoft.com>",
"date": "Mon, 26 Jan 2026 15:07:18 -0800",
"thread_id": "aYDUOeXIoOV4qtRk@skinsburskii.localdomain.mbox.gz"
} |
lkml | [PATCH] mshv: Make MSHV mutually exclusive with KEXEC | The MSHV driver deposits kernel-allocated pages to the hypervisor during
runtime and never withdraws them. This creates a fundamental incompatibility
with KEXEC, as these deposited pages remain unavailable to the new kernel
loaded via KEXEC, leading to potential system crashes upon kernel accessing
hypervisor deposited... | On Mon, Jan 26, 2026 at 03:07:18PM -0800, Mukesh R wrote:
This quick hack you mention isn't quick in the upstream kernel as there
is no hook to interrupt kexec process except the live update one.
I sent an RFC for that one but given todays conversation details is
won't be accepted as is.
Making mshv mutually exclusive... | {
"author": "Stanislav Kinsburskii <skinsburskii@linux.microsoft.com>",
"date": "Mon, 26 Jan 2026 16:21:43 -0800",
"thread_id": "aYDUOeXIoOV4qtRk@skinsburskii.localdomain.mbox.gz"
} |
lkml | [PATCH] mshv: Make MSHV mutually exclusive with KEXEC | The MSHV driver deposits kernel-allocated pages to the hypervisor during
runtime and never withdraws them. This creates a fundamental incompatibility
with KEXEC, as these deposited pages remain unavailable to the new kernel
loaded via KEXEC, leading to potential system crashes upon kernel accessing
hypervisor deposited... | On 1/26/26 16:21, Stanislav Kinsburskii wrote:
That's the one we want to interrupt and block right? crash kexec
is ok and should be allowed. We can document we don't support kexec
for update for now.
Are you taking about this?
"mshv: Add kexec safety for deposited pages"
Yeah, that could take a long time... | {
"author": "Mukesh R <mrathor@linux.microsoft.com>",
"date": "Mon, 26 Jan 2026 17:39:49 -0800",
"thread_id": "aYDUOeXIoOV4qtRk@skinsburskii.localdomain.mbox.gz"
} |
lkml | [PATCH] mshv: Make MSHV mutually exclusive with KEXEC | The MSHV driver deposits kernel-allocated pages to the hypervisor during
runtime and never withdraws them. This creates a fundamental incompatibility
with KEXEC, as these deposited pages remain unavailable to the new kernel
loaded via KEXEC, leading to potential system crashes upon kernel accessing
hypervisor deposited... | On Mon, Jan 26, 2026 at 05:39:49PM -0800, Mukesh R wrote:
Yes.
The trade-off here is between disabling kexec support and having the
kernel crash after kexec in a non-obvious way. This affects both regular
kexec and crash kexec.
It’s a pity we can’t apply a quick hack to disable only regular kexec.
However, since cr... | {
"author": "Stanislav Kinsburskii <skinsburskii@linux.microsoft.com>",
"date": "Tue, 27 Jan 2026 09:47:01 -0800",
"thread_id": "aYDUOeXIoOV4qtRk@skinsburskii.localdomain.mbox.gz"
} |
lkml | [PATCH] mshv: Make MSHV mutually exclusive with KEXEC | The MSHV driver deposits kernel-allocated pages to the hypervisor during
runtime and never withdraws them. This creates a fundamental incompatibility
with KEXEC, as these deposited pages remain unavailable to the new kernel
loaded via KEXEC, leading to potential system crashes upon kernel accessing
hypervisor deposited... | On 1/27/26 09:47, Stanislav Kinsburskii wrote:
crash kexec on baremetal is not affected, hence disabling that
doesn't make sense as we can't debug crashes then on bm.
Let me think and explore a bit, and if I come up with something, I'll
send a patch here. If nothing, then we can do this as last resort.
Thanks,
-Muke... | {
"author": "Mukesh R <mrathor@linux.microsoft.com>",
"date": "Tue, 27 Jan 2026 11:56:02 -0800",
"thread_id": "aYDUOeXIoOV4qtRk@skinsburskii.localdomain.mbox.gz"
} |
lkml | [PATCH] mshv: Make MSHV mutually exclusive with KEXEC | The MSHV driver deposits kernel-allocated pages to the hypervisor during
runtime and never withdraws them. This creates a fundamental incompatibility
with KEXEC, as these deposited pages remain unavailable to the new kernel
loaded via KEXEC, leading to potential system crashes upon kernel accessing
hypervisor deposited... | From: Mukesh R <mrathor@linux.microsoft.com> Sent: Tuesday, January 27, 2026 11:56 AM
Maybe you've already looked at this, but there's a sysctl parameter
kernel.kexec_load_limit_reboot that prevents loading a kexec
kernel for reboot if the value is zero. Separately, there is
kernel.kexec_load_limit_panic that con... | {
"author": "Michael Kelley <mhklinux@outlook.com>",
"date": "Wed, 28 Jan 2026 15:53:04 +0000",
"thread_id": "aYDUOeXIoOV4qtRk@skinsburskii.localdomain.mbox.gz"
} |
lkml | [PATCH] mshv: Make MSHV mutually exclusive with KEXEC | The MSHV driver deposits kernel-allocated pages to the hypervisor during
runtime and never withdraws them. This creates a fundamental incompatibility
with KEXEC, as these deposited pages remain unavailable to the new kernel
loaded via KEXEC, leading to potential system crashes upon kernel accessing
hypervisor deposited... | On Mon, Jan 26, 2026 at 12:46:44PM -0800, Stanislav Kinsburskii wrote:
All pages that were deposited in the context of a guest partition (i.e.
with the guest partition ID), would be withdrawn when you kill the VMs,
right? What other deposited pages would be left?
Thanks,
Anirudh. | {
"author": "Anirudh Rayabharam <anirudh@anirudhrb.com>",
"date": "Wed, 28 Jan 2026 16:16:31 +0000",
"thread_id": "aYDUOeXIoOV4qtRk@skinsburskii.localdomain.mbox.gz"
} |
lkml | [PATCH] mshv: Make MSHV mutually exclusive with KEXEC | The MSHV driver deposits kernel-allocated pages to the hypervisor during
runtime and never withdraws them. This creates a fundamental incompatibility
with KEXEC, as these deposited pages remain unavailable to the new kernel
loaded via KEXEC, leading to potential system crashes upon kernel accessing
hypervisor deposited... | On Tue, Jan 27, 2026 at 11:56:02AM -0800, Mukesh R wrote:
Bare metal support is not currently relevant, as it is not available.
This is the upstream kernel, and this driver will be accessible to
third-party customers beginning with kernel 6.19 for running their
kernels in Azure L1VH, so consistency is required.
Thank... | {
"author": "Stanislav Kinsburskii <skinsburskii@linux.microsoft.com>",
"date": "Wed, 28 Jan 2026 15:08:30 -0800",
"thread_id": "aYDUOeXIoOV4qtRk@skinsburskii.localdomain.mbox.gz"
} |
lkml | [PATCH] mshv: Make MSHV mutually exclusive with KEXEC | The MSHV driver deposits kernel-allocated pages to the hypervisor during
runtime and never withdraws them. This creates a fundamental incompatibility
with KEXEC, as these deposited pages remain unavailable to the new kernel
loaded via KEXEC, leading to potential system crashes upon kernel accessing
hypervisor deposited... | On Wed, Jan 28, 2026 at 04:16:31PM +0000, Anirudh Rayabharam wrote:
The driver deposits two types of pages: one for the guests (withdrawn
upon gust shutdown) and the other - for the host itself (never
withdrawn).
See hv_call_create_partition, for example: it deposits pages for the
host partition.
Thanks,
Stanislav | {
"author": "Stanislav Kinsburskii <skinsburskii@linux.microsoft.com>",
"date": "Wed, 28 Jan 2026 15:11:14 -0800",
"thread_id": "aYDUOeXIoOV4qtRk@skinsburskii.localdomain.mbox.gz"
} |
lkml | [PATCH] mshv: Make MSHV mutually exclusive with KEXEC | The MSHV driver deposits kernel-allocated pages to the hypervisor during
runtime and never withdraws them. This creates a fundamental incompatibility
with KEXEC, as these deposited pages remain unavailable to the new kernel
loaded via KEXEC, leading to potential system crashes upon kernel accessing
hypervisor deposited... | On 1/28/26 07:53, Michael Kelley wrote:
Mmm...eee...weelll... i think i see a much easier way to do this by
just hijacking __kexec_lock. I will resume my normal work tmrw/Fri,
so let me test it out. if it works, will send patch Monday.
Thanks,
-Mukesh | {
"author": "Mukesh R <mrathor@linux.microsoft.com>",
"date": "Thu, 29 Jan 2026 18:52:59 -0800",
"thread_id": "aYDUOeXIoOV4qtRk@skinsburskii.localdomain.mbox.gz"
} |
lkml | [PATCH] mshv: Make MSHV mutually exclusive with KEXEC | The MSHV driver deposits kernel-allocated pages to the hypervisor during
runtime and never withdraws them. This creates a fundamental incompatibility
with KEXEC, as these deposited pages remain unavailable to the new kernel
loaded via KEXEC, leading to potential system crashes upon kernel accessing
hypervisor deposited... | On 1/28/26 15:08, Stanislav Kinsburskii wrote:
Well, without crashdump support, customers will not be running anything
anywhere.
Thanks,
-Mukesh | {
"author": "Mukesh R <mrathor@linux.microsoft.com>",
"date": "Thu, 29 Jan 2026 18:59:31 -0800",
"thread_id": "aYDUOeXIoOV4qtRk@skinsburskii.localdomain.mbox.gz"
} |
lkml | [PATCH] mshv: Make MSHV mutually exclusive with KEXEC | The MSHV driver deposits kernel-allocated pages to the hypervisor during
runtime and never withdraws them. This creates a fundamental incompatibility
with KEXEC, as these deposited pages remain unavailable to the new kernel
loaded via KEXEC, leading to potential system crashes upon kernel accessing
hypervisor deposited... | On Wed, Jan 28, 2026 at 03:11:14PM -0800, Stanislav Kinsburskii wrote:
Hmm.. I see. Is it not possible to reclaim this memory in module_exit?
Also, can't we forcefully kill all running partitions in module_exit and
then reclaim memory? Would this help with kernel consistency
irrespective of userspace behavior?
Thanks... | {
"author": "Anirudh Rayabharam <anirudh@anirudhrb.com>",
"date": "Fri, 30 Jan 2026 17:11:12 +0000",
"thread_id": "aYDUOeXIoOV4qtRk@skinsburskii.localdomain.mbox.gz"
} |
lkml | [PATCH] mshv: Make MSHV mutually exclusive with KEXEC | The MSHV driver deposits kernel-allocated pages to the hypervisor during
runtime and never withdraws them. This creates a fundamental incompatibility
with KEXEC, as these deposited pages remain unavailable to the new kernel
loaded via KEXEC, leading to potential system crashes upon kernel accessing
hypervisor deposited... | On Thu, Jan 29, 2026 at 06:59:31PM -0800, Mukesh R wrote:
This is my concern too. I don't think customers will be particularly
happy that kexec doesn't work with our driver.
Thanks,
Anirudh | {
"author": "Anirudh Rayabharam <anirudh@anirudhrb.com>",
"date": "Fri, 30 Jan 2026 17:17:52 +0000",
"thread_id": "aYDUOeXIoOV4qtRk@skinsburskii.localdomain.mbox.gz"
} |
lkml | [PATCH] mshv: Make MSHV mutually exclusive with KEXEC | The MSHV driver deposits kernel-allocated pages to the hypervisor during
runtime and never withdraws them. This creates a fundamental incompatibility
with KEXEC, as these deposited pages remain unavailable to the new kernel
loaded via KEXEC, leading to potential system crashes upon kernel accessing
hypervisor deposited... | On Fri, Jan 30, 2026 at 05:17:52PM +0000, Anirudh Rayabharam wrote:
I wasn’t clear earlier, so let me restate it. Today, kexec is not
supported in L1VH. This is a bug we have not fixed yet. Disabling kexec
is not a long-term solution. But it is better to disable it explicitly
than to have kernel crashes after kexec.
... | {
"author": "Stanislav Kinsburskii <skinsburskii@linux.microsoft.com>",
"date": "Fri, 30 Jan 2026 10:41:39 -0800",
"thread_id": "aYDUOeXIoOV4qtRk@skinsburskii.localdomain.mbox.gz"
} |
lkml | [PATCH] mshv: Make MSHV mutually exclusive with KEXEC | The MSHV driver deposits kernel-allocated pages to the hypervisor during
runtime and never withdraws them. This creates a fundamental incompatibility
with KEXEC, as these deposited pages remain unavailable to the new kernel
loaded via KEXEC, leading to potential system crashes upon kernel accessing
hypervisor deposited... | On Fri, Jan 30, 2026 at 05:11:12PM +0000, Anirudh Rayabharam wrote:
It would, but this is sloppy and cannot be a long-term solution.
It is also not reliable. We have no hook to prevent kexec. So if we fail
to kill the guest or reclaim the memory for any reason, the new kernel
may still crash.
There are two long-term... | {
"author": "Stanislav Kinsburskii <skinsburskii@linux.microsoft.com>",
"date": "Fri, 30 Jan 2026 10:46:45 -0800",
"thread_id": "aYDUOeXIoOV4qtRk@skinsburskii.localdomain.mbox.gz"
} |
lkml | [PATCH] mshv: Make MSHV mutually exclusive with KEXEC | The MSHV driver deposits kernel-allocated pages to the hypervisor during
runtime and never withdraws them. This creates a fundamental incompatibility
with KEXEC, as these deposited pages remain unavailable to the new kernel
loaded via KEXEC, leading to potential system crashes upon kernel accessing
hypervisor deposited... | On 1/30/26 10:41, Stanislav Kinsburskii wrote:
I don't think there is disagreement on this. The undesired part is turning
off KEXEC config completely.
Thanks,
-Mukesh | {
"author": "Mukesh R <mrathor@linux.microsoft.com>",
"date": "Fri, 30 Jan 2026 11:47:48 -0800",
"thread_id": "aYDUOeXIoOV4qtRk@skinsburskii.localdomain.mbox.gz"
} |
lkml | [PATCH] mshv: Make MSHV mutually exclusive with KEXEC | The MSHV driver deposits kernel-allocated pages to the hypervisor during
runtime and never withdraws them. This creates a fundamental incompatibility
with KEXEC, as these deposited pages remain unavailable to the new kernel
loaded via KEXEC, leading to potential system crashes upon kernel accessing
hypervisor deposited... | On Fri, Jan 30, 2026 at 10:46:45AM -0800, Stanislav Kinsburskii wrote:
Actually guests won't be running by the time we reach our module_exit
function during a kexec. Userspace processes would've been killed by
then.
Also, why is this sloppy? Isn't this what module_exit should be
doing anyway? If someone unloads our m... | {
"author": "Anirudh Rayabharam <anirudh@anirudhrb.com>",
"date": "Fri, 30 Jan 2026 20:32:45 +0000",
"thread_id": "aYDUOeXIoOV4qtRk@skinsburskii.localdomain.mbox.gz"
} |
lkml | [PATCH] mshv: Make MSHV mutually exclusive with KEXEC | The MSHV driver deposits kernel-allocated pages to the hypervisor during
runtime and never withdraws them. This creates a fundamental incompatibility
with KEXEC, as these deposited pages remain unavailable to the new kernel
loaded via KEXEC, leading to potential system crashes upon kernel accessing
hypervisor deposited... | On Fri, Jan 30, 2026 at 11:47:48AM -0800, Mukesh R wrote:
There is no disagreement on this either. If you have a better solution
that can be implemented and merged before next kernel merge window,
please propose it. Otherwise, this patch will remain as is for now.
Thanks,
Stanislav | {
"author": "Stanislav Kinsburskii <skinsburskii@linux.microsoft.com>",
"date": "Mon, 2 Feb 2026 08:43:37 -0800",
"thread_id": "aYDUOeXIoOV4qtRk@skinsburskii.localdomain.mbox.gz"
} |
lkml | [PATCH] mshv: Make MSHV mutually exclusive with KEXEC | The MSHV driver deposits kernel-allocated pages to the hypervisor during
runtime and never withdraws them. This creates a fundamental incompatibility
with KEXEC, as these deposited pages remain unavailable to the new kernel
loaded via KEXEC, leading to potential system crashes upon kernel accessing
hypervisor deposited... | On 1/24/2026 3:50 AM, Stanislav Kinsburskii wrote:
I have not gone through entire conversation that has happened already on
this, but if you send a next version for this, please change commit msg
and subject to include MSHV_ROOT instead of MSHV, to avoid confusion.
Regards,
Naman | {
"author": "Naman Jain <namjain@linux.microsoft.com>",
"date": "Mon, 2 Feb 2026 22:26:10 +0530",
"thread_id": "aYDUOeXIoOV4qtRk@skinsburskii.localdomain.mbox.gz"
} |
lkml | [PATCH] mshv: Make MSHV mutually exclusive with KEXEC | The MSHV driver deposits kernel-allocated pages to the hypervisor during
runtime and never withdraws them. This creates a fundamental incompatibility
with KEXEC, as these deposited pages remain unavailable to the new kernel
loaded via KEXEC, leading to potential system crashes upon kernel accessing
hypervisor deposited... | On Fri, Jan 30, 2026 at 08:32:45PM +0000, Anirudh Rayabharam wrote:
No, they will not: "kexec -e" doesn't kill user processes.
We must not rely on OS to do graceful shutdown before doing
kexec.
Kexec does not unload modules, but it doesn't really matter even if it
would.
There are other means to plug into the reboot... | {
"author": "Stanislav Kinsburskii <skinsburskii@linux.microsoft.com>",
"date": "Mon, 2 Feb 2026 09:10:00 -0800",
"thread_id": "aYDUOeXIoOV4qtRk@skinsburskii.localdomain.mbox.gz"
} |
lkml | [PATCH] mshv: Make MSHV mutually exclusive with KEXEC | The MSHV driver deposits kernel-allocated pages to the hypervisor during
runtime and never withdraws them. This creates a fundamental incompatibility
with KEXEC, as these deposited pages remain unavailable to the new kernel
loaded via KEXEC, leading to potential system crashes upon kernel accessing
hypervisor deposited... | On Fri, Jan 30, 2026 at 05:11:12PM +0000, Anirudh Rayabharam wrote:
First, module_exit is not called during kexec. Second, forcefully
killing all partitions during a kexec reboot would be bulky,
error-prone, and slow. It also does not guarantee robust behavior. Too
many things can go wrong, and we could still end up i... | {
"author": "Stanislav Kinsburskii <skinsburskii@linux.microsoft.com>",
"date": "Mon, 2 Feb 2026 10:09:38 -0800",
"thread_id": "aYDUOeXIoOV4qtRk@skinsburskii.localdomain.mbox.gz"
} |
lkml | [PATCH 1/2] vduse: avoid adding implicit padding | From: Arnd Bergmann <arnd@arndb.de>
The vduse_iova_range_v2 and vduse_iotlb_entry_v2 structures are both
defined in a way that adds implicit padding and is incompatible between
i386 and x86_64 userspace because of the different structure alignment
requirements. Building the header with -Wpadded shows these new warning... | From: Arnd Bergmann <arnd@arndb.de>
These two ioctls are incompatible on 32-bit x86 userspace, because
the data structures are shorter than they are on 64-bit.
Add compad handling to the regular ioctl handler to just handle
them the same way and ignore the extra padding. This could be
done in a separate .compat_ioctl... | {
"author": "Arnd Bergmann <arnd@kernel.org>",
"date": "Mon, 2 Feb 2026 10:59:32 +0100",
"thread_id": "20260202095940.1358613-1-arnd@kernel.org.mbox.gz"
} |
lkml | [PATCH 1/2] vduse: avoid adding implicit padding | From: Arnd Bergmann <arnd@arndb.de>
The vduse_iova_range_v2 and vduse_iotlb_entry_v2 structures are both
defined in a way that adds implicit padding and is incompatible between
i386 and x86_64 userspace because of the different structure alignment
requirements. Building the header with -Wpadded shows these new warning... | On Mon, Feb 2, 2026 at 11:06 AM Arnd Bergmann <arnd@kernel.org> wrote:
s/indiviudally/individually/ if v2
That's something I didn't take into account, thanks!
I did not know about _IOC_SIZE and I like how it reduces the complexity, thanks!
As a proposal, maybe we can add MIN(_IOC_SIZE, sizeof(entry)) ? Not
sure i... | {
"author": "Eugenio Perez Martin <eperezma@redhat.com>",
"date": "Mon, 2 Feb 2026 12:28:26 +0100",
"thread_id": "20260202095940.1358613-1-arnd@kernel.org.mbox.gz"
} |
lkml | [PATCH 1/2] vduse: avoid adding implicit padding | From: Arnd Bergmann <arnd@arndb.de>
The vduse_iova_range_v2 and vduse_iotlb_entry_v2 structures are both
defined in a way that adds implicit padding and is incompatible between
i386 and x86_64 userspace because of the different structure alignment
requirements. Building the header with -Wpadded shows these new warning... | On Mon, Feb 2, 2026 at 11:07 AM Arnd Bergmann <arnd@kernel.org> wrote:
I'm just learning about the COMPAT_ stuff but does this mean the
userland app need to call a different ioctl depending if it is
compiled for 32 bits or 64 bits? I guess it is not the case, but how
is that handled? | {
"author": "Eugenio Perez Martin <eperezma@redhat.com>",
"date": "Mon, 2 Feb 2026 12:34:48 +0100",
"thread_id": "20260202095940.1358613-1-arnd@kernel.org.mbox.gz"
} |
lkml | [PATCH 1/2] vduse: avoid adding implicit padding | From: Arnd Bergmann <arnd@arndb.de>
The vduse_iova_range_v2 and vduse_iotlb_entry_v2 structures are both
defined in a way that adds implicit padding and is incompatible between
i386 and x86_64 userspace because of the different structure alignment
requirements. Building the header with -Wpadded shows these new warning... | On Mon, Feb 2, 2026 at 12:28 PM Eugenio Perez Martin
<eperezma@redhat.com> wrote:
(I hit "Send" too early).
We could make this padding[3] so reserved keeps being [12]. This way
the struct members keep the same alignment between the commits. Not
super important as there should not be a lot of users of this right
now, ... | {
"author": "Eugenio Perez Martin <eperezma@redhat.com>",
"date": "Mon, 2 Feb 2026 12:50:49 +0100",
"thread_id": "20260202095940.1358613-1-arnd@kernel.org.mbox.gz"
} |
lkml | [PATCH 1/2] vduse: avoid adding implicit padding | From: Arnd Bergmann <arnd@arndb.de>
The vduse_iova_range_v2 and vduse_iotlb_entry_v2 structures are both
defined in a way that adds implicit padding and is incompatible between
i386 and x86_64 userspace because of the different structure alignment
requirements. Building the header with -Wpadded shows these new warning... | On Mon, Feb 2, 2026, at 12:34, Eugenio Perez Martin wrote:
In a definition like
#define VDUSE_IOTLB_GET_FD _IOWR(VDUSE_BASE, 0x10, struct vduse_iotlb_entry)
The resulting integer value encodes sizeof(struct vduse_iotlb_entry)
in some of the bits. Since x86-32 and x86-64 have different
sizes for this particular ... | {
"author": "\"Arnd Bergmann\" <arnd@arndb.de>",
"date": "Mon, 02 Feb 2026 12:59:03 +0100",
"thread_id": "20260202095940.1358613-1-arnd@kernel.org.mbox.gz"
} |
lkml | [PATCH 1/2] vduse: avoid adding implicit padding | From: Arnd Bergmann <arnd@arndb.de>
The vduse_iova_range_v2 and vduse_iotlb_entry_v2 structures are both
defined in a way that adds implicit padding and is incompatible between
i386 and x86_64 userspace because of the different structure alignment
requirements. Building the header with -Wpadded shows these new warning... | On Mon, Feb 2, 2026, at 12:50, Eugenio Perez Martin wrote:
I think it's more readable without the MIN(), but I don't mind
adding it either.
I think that is too risky, as it would overlay 'asid' on top of
previously uninitialized padding fields coming from userspace
on most architectures. Since there was previously n... | {
"author": "\"Arnd Bergmann\" <arnd@arndb.de>",
"date": "Mon, 02 Feb 2026 13:06:54 +0100",
"thread_id": "20260202095940.1358613-1-arnd@kernel.org.mbox.gz"
} |
lkml | [PATCH 1/2] vduse: avoid adding implicit padding | From: Arnd Bergmann <arnd@arndb.de>
The vduse_iova_range_v2 and vduse_iotlb_entry_v2 structures are both
defined in a way that adds implicit padding and is incompatible between
i386 and x86_64 userspace because of the different structure alignment
requirements. Building the header with -Wpadded shows these new warning... | On Mon, Feb 02, 2026 at 12:59:03PM +0100, Arnd Bergmann wrote:
I think .compat_ioctl would be cleaner frankly. Just look at
all the ifdefery. And who knows what broken-ness userspace
comes up with with this approach. Better use the standard approach. | {
"author": "\"Michael S. Tsirkin\" <mst@redhat.com>",
"date": "Mon, 2 Feb 2026 11:45:13 -0500",
"thread_id": "20260202095940.1358613-1-arnd@kernel.org.mbox.gz"
} |
lkml | [PATCH 0/3] jbd2/ext4/ocfs2: READ_ONCE for lockless jinode reads | This series adds READ_ONCE() for existing lockless reads of
jbd2_inode fields in jbd2 and filesystem callbacks used by ext4 and ocfs2.
This is based on Jan's suggestion in the review of the ext4 jinode
publication race fix. [1]
[1]: https://lore.kernel.org/all/4jxwogttddiaoqbstlgou5ox6zs27ngjjz5ukrxafm2z5ijxod@so4eqn... | jbd2_inode fields are updated under journal->j_list_lock, but some
paths read them without holding the lock (e.g. fast commit
helpers and the ordered truncate fast path).
Use READ_ONCE() for these lockless reads to correct the
concurrency assumptions.
Suggested-by: Jan Kara <jack@suse.com>
Signed-off-by: Li Chen <me@... | {
"author": "Li Chen <me@linux.beauty>",
"date": "Fri, 30 Jan 2026 11:12:30 +0800",
"thread_id": "nxltvmkavegi5tedwzb5g4gt5vzyjvsmkmg24sej74q7b5nvfm@o5u6uivv7sm7.mbox.gz"
} |
lkml | [PATCH 0/3] jbd2/ext4/ocfs2: READ_ONCE for lockless jinode reads | This series adds READ_ONCE() for existing lockless reads of
jbd2_inode fields in jbd2 and filesystem callbacks used by ext4 and ocfs2.
This is based on Jan's suggestion in the review of the ext4 jinode
publication race fix. [1]
[1]: https://lore.kernel.org/all/4jxwogttddiaoqbstlgou5ox6zs27ngjjz5ukrxafm2z5ijxod@so4eqn... | ext4 journal commit callbacks access jbd2_inode fields such as
i_transaction and i_dirty_start/end without holding journal->j_list_lock.
Use READ_ONCE() for these reads to correct the concurrency assumptions.
Suggested-by: Jan Kara <jack@suse.com>
Signed-off-by: Li Chen <me@linux.beauty>
---
fs/ext4/inode.c | 6 +++... | {
"author": "Li Chen <me@linux.beauty>",
"date": "Fri, 30 Jan 2026 11:12:31 +0800",
"thread_id": "nxltvmkavegi5tedwzb5g4gt5vzyjvsmkmg24sej74q7b5nvfm@o5u6uivv7sm7.mbox.gz"
} |
lkml | [PATCH 0/3] jbd2/ext4/ocfs2: READ_ONCE for lockless jinode reads | This series adds READ_ONCE() for existing lockless reads of
jbd2_inode fields in jbd2 and filesystem callbacks used by ext4 and ocfs2.
This is based on Jan's suggestion in the review of the ext4 jinode
publication race fix. [1]
[1]: https://lore.kernel.org/all/4jxwogttddiaoqbstlgou5ox6zs27ngjjz5ukrxafm2z5ijxod@so4eqn... | ocfs2 journal commit callback reads jbd2_inode dirty range fields without
holding journal->j_list_lock.
Use READ_ONCE() for these reads to correct the concurrency assumptions.
Suggested-by: Jan Kara <jack@suse.com>
Signed-off-by: Li Chen <me@linux.beauty>
---
fs/ocfs2/journal.c | 7 +++++--
1 file changed, 5 inserti... | {
"author": "Li Chen <me@linux.beauty>",
"date": "Fri, 30 Jan 2026 11:12:32 +0800",
"thread_id": "nxltvmkavegi5tedwzb5g4gt5vzyjvsmkmg24sej74q7b5nvfm@o5u6uivv7sm7.mbox.gz"
} |
lkml | [PATCH 0/3] jbd2/ext4/ocfs2: READ_ONCE for lockless jinode reads | This series adds READ_ONCE() for existing lockless reads of
jbd2_inode fields in jbd2 and filesystem callbacks used by ext4 and ocfs2.
This is based on Jan's suggestion in the review of the ext4 jinode
publication race fix. [1]
[1]: https://lore.kernel.org/all/4jxwogttddiaoqbstlgou5ox6zs27ngjjz5ukrxafm2z5ijxod@so4eqn... | On Fri, Jan 30, 2026 at 11:12:32AM +0800, Li Chen wrote:
I don't think this is the right solution to the problem. If it is,
there needs to be much better argumentation in the commit message.
As I understand it, jbd2_journal_file_inode() initialises jinode,
then adds it to the t_inode_list, then drops the j_list_lock... | {
"author": "Matthew Wilcox <willy@infradead.org>",
"date": "Fri, 30 Jan 2026 05:27:59 +0000",
"thread_id": "nxltvmkavegi5tedwzb5g4gt5vzyjvsmkmg24sej74q7b5nvfm@o5u6uivv7sm7.mbox.gz"
} |
lkml | [PATCH 0/3] jbd2/ext4/ocfs2: READ_ONCE for lockless jinode reads | This series adds READ_ONCE() for existing lockless reads of
jbd2_inode fields in jbd2 and filesystem callbacks used by ext4 and ocfs2.
This is based on Jan's suggestion in the review of the ext4 jinode
publication race fix. [1]
[1]: https://lore.kernel.org/all/4jxwogttddiaoqbstlgou5ox6zs27ngjjz5ukrxafm2z5ijxod@so4eqn... | Hi Matthew,
> On Fri, Jan 30, 2026 at 11:12:32AM +0800, Li Chen wrote:
> > ocfs2 journal commit callback reads jbd2_inode dirty range fields without
> > holding journal->j_list_lock.
> >
> > Use READ_ONCE() for these reads to correct the concurrency assumptions.
>
> I don't think this is the right solution to... | {
"author": "Li Chen <me@linux.beauty>",
"date": "Fri, 30 Jan 2026 20:26:40 +0800",
"thread_id": "nxltvmkavegi5tedwzb5g4gt5vzyjvsmkmg24sej74q7b5nvfm@o5u6uivv7sm7.mbox.gz"
} |
lkml | [PATCH 0/3] jbd2/ext4/ocfs2: READ_ONCE for lockless jinode reads | This series adds READ_ONCE() for existing lockless reads of
jbd2_inode fields in jbd2 and filesystem callbacks used by ext4 and ocfs2.
This is based on Jan's suggestion in the review of the ext4 jinode
publication race fix. [1]
[1]: https://lore.kernel.org/all/4jxwogttddiaoqbstlgou5ox6zs27ngjjz5ukrxafm2z5ijxod@so4eqn... | On Fri, Jan 30, 2026 at 08:26:40PM +0800, Li Chen wrote:
I think that's the only issue that exists ...
I don't think that's true. I think what you're asserting is that:
int *pi;
int **ppi;
spin_lock(&lock);
*pi = 1;
*ppi = pi;
spin_unlock(&lock);
that the store to *pi must be observed before the store to *... | {
"author": "Matthew Wilcox <willy@infradead.org>",
"date": "Fri, 30 Jan 2026 16:36:28 +0000",
"thread_id": "nxltvmkavegi5tedwzb5g4gt5vzyjvsmkmg24sej74q7b5nvfm@o5u6uivv7sm7.mbox.gz"
} |
lkml | [PATCH 0/3] jbd2/ext4/ocfs2: READ_ONCE for lockless jinode reads | This series adds READ_ONCE() for existing lockless reads of
jbd2_inode fields in jbd2 and filesystem callbacks used by ext4 and ocfs2.
This is based on Jan's suggestion in the review of the ext4 jinode
publication race fix. [1]
[1]: https://lore.kernel.org/all/4jxwogttddiaoqbstlgou5ox6zs27ngjjz5ukrxafm2z5ijxod@so4eqn... | Hi Matthew,
Thank you very much for the detailed explanation and for your patience.
On Sat, 31 Jan 2026 00:36:28 +0800,
Matthew Wilcox wrote:
Understood.
Yes, agreed $B!=(B thank you. I was implicitly assuming the reader had taken the same lock
at some point, which is not a valid assumption for a lockless reader... | {
"author": "Li Chen <me@linux.beauty>",
"date": "Sun, 01 Feb 2026 12:37:36 +0800",
"thread_id": "nxltvmkavegi5tedwzb5g4gt5vzyjvsmkmg24sej74q7b5nvfm@o5u6uivv7sm7.mbox.gz"
} |
lkml | [PATCH 0/3] jbd2/ext4/ocfs2: READ_ONCE for lockless jinode reads | This series adds READ_ONCE() for existing lockless reads of
jbd2_inode fields in jbd2 and filesystem callbacks used by ext4 and ocfs2.
This is based on Jan's suggestion in the review of the ext4 jinode
publication race fix. [1]
[1]: https://lore.kernel.org/all/4jxwogttddiaoqbstlgou5ox6zs27ngjjz5ukrxafm2z5ijxod@so4eqn... | On Fri 30-01-26 11:12:30, Li Chen wrote:
Just one nit below. With that fixed feel free to add:
Reviewed-by: Jan Kara <jack@suse.cz>
i_vfs_inode never changes so READ_ONCE is pointless here.
Honza
--
Jan Kara <jack@suse.com>
SUSE Labs, CR | {
"author": "Jan Kara <jack@suse.cz>",
"date": "Mon, 2 Feb 2026 17:40:45 +0100",
"thread_id": "nxltvmkavegi5tedwzb5g4gt5vzyjvsmkmg24sej74q7b5nvfm@o5u6uivv7sm7.mbox.gz"
} |
lkml | [PATCH 0/3] jbd2/ext4/ocfs2: READ_ONCE for lockless jinode reads | This series adds READ_ONCE() for existing lockless reads of
jbd2_inode fields in jbd2 and filesystem callbacks used by ext4 and ocfs2.
This is based on Jan's suggestion in the review of the ext4 jinode
publication race fix. [1]
[1]: https://lore.kernel.org/all/4jxwogttddiaoqbstlgou5ox6zs27ngjjz5ukrxafm2z5ijxod@so4eqn... | On Fri 30-01-26 11:12:31, Li Chen wrote:
Looks good. Feel free to add:
Reviewed-by: Jan Kara <jack@suse.cz>
Honza
--
Jan Kara <jack@suse.com>
SUSE Labs, CR | {
"author": "Jan Kara <jack@suse.cz>",
"date": "Mon, 2 Feb 2026 17:41:39 +0100",
"thread_id": "nxltvmkavegi5tedwzb5g4gt5vzyjvsmkmg24sej74q7b5nvfm@o5u6uivv7sm7.mbox.gz"
} |
lkml | [PATCH 0/3] jbd2/ext4/ocfs2: READ_ONCE for lockless jinode reads | This series adds READ_ONCE() for existing lockless reads of
jbd2_inode fields in jbd2 and filesystem callbacks used by ext4 and ocfs2.
This is based on Jan's suggestion in the review of the ext4 jinode
publication race fix. [1]
[1]: https://lore.kernel.org/all/4jxwogttddiaoqbstlgou5ox6zs27ngjjz5ukrxafm2z5ijxod@so4eqn... | On Mon 02-02-26 17:40:45, Jan Kara wrote:
One more note: I've realized that for this to work you also need to make
jbd2_journal_file_inode() use WRITE_ONCE() when updating i_dirty_start,
i_dirty_end and i_flags.
Honza
--
Jan Kara <jack@suse.com>
SUSE Labs, CR | {
"author": "Jan Kara <jack@suse.cz>",
"date": "Mon, 2 Feb 2026 17:52:30 +0100",
"thread_id": "nxltvmkavegi5tedwzb5g4gt5vzyjvsmkmg24sej74q7b5nvfm@o5u6uivv7sm7.mbox.gz"
} |
lkml | [PATCH 0/3] jbd2/ext4/ocfs2: READ_ONCE for lockless jinode reads | This series adds READ_ONCE() for existing lockless reads of
jbd2_inode fields in jbd2 and filesystem callbacks used by ext4 and ocfs2.
This is based on Jan's suggestion in the review of the ext4 jinode
publication race fix. [1]
[1]: https://lore.kernel.org/all/4jxwogttddiaoqbstlgou5ox6zs27ngjjz5ukrxafm2z5ijxod@so4eqn... | On Fri 30-01-26 16:36:28, Matthew Wilcox wrote:
Well, the above reasonably accurately describes the code making jinode
visible. The reader code is like:
spin_lock(&lock);
pi = *ppi;
spin_unlock(&lock);
work with pi
so it is guaranteed to see pi properly initialized. The problem is that
"work with pi" can... | {
"author": "Jan Kara <jack@suse.cz>",
"date": "Mon, 2 Feb 2026 18:17:49 +0100",
"thread_id": "nxltvmkavegi5tedwzb5g4gt5vzyjvsmkmg24sej74q7b5nvfm@o5u6uivv7sm7.mbox.gz"
} |
lkml | [PATCH 0/4] ASoC: ti: davinci-mcasp: Add asynchronous mode support for McASP | This series adds asynchronous mode support to the McASP driver, which
enables independent configuration of bitclocks, frame sync, and audio
configurations between tx(playback) and rx(record). And achieves
simultaneous playback & record using different audio configurations.
It also adds two clean up patches to the McAS... | Simplify the mcasp_set_clk_pdir caller convention in start/stop stream
function, to make it so that set_clk_pdir gets called regardless when
stream starts and also disables when stream ends.
Functionality-wise, everything remains the same as the previously skipped
calls are now either correctly configured
(when McASP ... | {
"author": "Sen Wang <sen@ti.com>",
"date": "Thu, 29 Jan 2026 23:10:43 -0600",
"thread_id": "d7ed59c4-2262-4cd5-978f-e9e5c0e8a9a9@gmail.com.mbox.gz"
} |
lkml | [PATCH 0/4] ASoC: ti: davinci-mcasp: Add asynchronous mode support for McASP | This series adds asynchronous mode support to the McASP driver, which
enables independent configuration of bitclocks, frame sync, and audio
configurations between tx(playback) and rx(record). And achieves
simultaneous playback & record using different audio configurations.
It also adds two clean up patches to the McAS... | The current mcasp_is_synchronous() function does more than what it
proclaims, it also checks if McASP is a frame producer.
Therefore split the original function into two separate ones and
replace all occurrences with the new equivalent logic. So the functions
can be re-used when checking async/sync status in light of ... | {
"author": "Sen Wang <sen@ti.com>",
"date": "Thu, 29 Jan 2026 23:10:42 -0600",
"thread_id": "d7ed59c4-2262-4cd5-978f-e9e5c0e8a9a9@gmail.com.mbox.gz"
} |
lkml | [PATCH 0/4] ASoC: ti: davinci-mcasp: Add asynchronous mode support for McASP | This series adds asynchronous mode support to the McASP driver, which
enables independent configuration of bitclocks, frame sync, and audio
configurations between tx(playback) and rx(record). And achieves
simultaneous playback & record using different audio configurations.
It also adds two clean up patches to the McAS... | McASP supports the independent configuration of TX & RX clk and frame
sync registers. By default, the driver is configured in synchronous mode
where RX clock generator is disabled and it uses transmit clock signals as
bit clock and frame sync. Therefore add optional properties needed for
asynchronous mode.
Add ti,asyn... | {
"author": "Sen Wang <sen@ti.com>",
"date": "Thu, 29 Jan 2026 23:10:41 -0600",
"thread_id": "d7ed59c4-2262-4cd5-978f-e9e5c0e8a9a9@gmail.com.mbox.gz"
} |
lkml | [PATCH 0/4] ASoC: ti: davinci-mcasp: Add asynchronous mode support for McASP | This series adds asynchronous mode support to the McASP driver, which
enables independent configuration of bitclocks, frame sync, and audio
configurations between tx(playback) and rx(record). And achieves
simultaneous playback & record using different audio configurations.
It also adds two clean up patches to the McAS... | McASP has dedicated clock & frame sync registers for both transmit
and receive. Currently McASP driver only supports synchronous behavior and
couples both TX & RX settings.
Add logic that enables asynchronous mode via ti,async-mode property. In
async mode, playback & record can be done simultaneously with different
au... | {
"author": "Sen Wang <sen@ti.com>",
"date": "Thu, 29 Jan 2026 23:10:44 -0600",
"thread_id": "d7ed59c4-2262-4cd5-978f-e9e5c0e8a9a9@gmail.com.mbox.gz"
} |
lkml | [PATCH 0/4] ASoC: ti: davinci-mcasp: Add asynchronous mode support for McASP | This series adds asynchronous mode support to the McASP driver, which
enables independent configuration of bitclocks, frame sync, and audio
configurations between tx(playback) and rx(record). And achieves
simultaneous playback & record using different audio configurations.
It also adds two clean up patches to the McAS... | On Thu, Jan 29, 2026 at 11:10:41PM -0600, Sen Wang wrote:
Please submit patches using subject lines reflecting the style for the
subsystem, this makes it easier for people to identify relevant patches.
Look at what existing commits in the area you're changing are doing and
make sure your subject lines visually resembl... | {
"author": "Mark Brown <broonie@kernel.org>",
"date": "Mon, 2 Feb 2026 12:44:32 +0000",
"thread_id": "d7ed59c4-2262-4cd5-978f-e9e5c0e8a9a9@gmail.com.mbox.gz"
} |
lkml | [PATCH 0/4] ASoC: ti: davinci-mcasp: Add asynchronous mode support for McASP | This series adds asynchronous mode support to the McASP driver, which
enables independent configuration of bitclocks, frame sync, and audio
configurations between tx(playback) and rx(record). And achieves
simultaneous playback & record using different audio configurations.
It also adds two clean up patches to the McAS... | On 30/01/2026 07:10, Sen Wang wrote:
True, the naming was not too precise. It is tasked to decide if the TX
clock needs to be enabled for RX operation, which precisely when McASP
is in synchronous mode _and_ it is clock provider.
Acked-by: Peter Ujfalusi <peter.ujfalusi@gmail.com>
davinci_mcasp *mcasp, u32 ctl_reg,... | {
"author": "=?UTF-8?Q?P=C3=A9ter_Ujfalusi?= <peter.ujfalusi@gmail.com>",
"date": "Mon, 2 Feb 2026 18:42:20 +0200",
"thread_id": "d7ed59c4-2262-4cd5-978f-e9e5c0e8a9a9@gmail.com.mbox.gz"
} |
lkml | [PATCH 0/4] ASoC: ti: davinci-mcasp: Add asynchronous mode support for McASP | This series adds asynchronous mode support to the McASP driver, which
enables independent configuration of bitclocks, frame sync, and audio
configurations between tx(playback) and rx(record). And achieves
simultaneous playback & record using different audio configurations.
It also adds two clean up patches to the McAS... | On 30/01/2026 07:10, Sen Wang wrote:
I'm not sure about this, but the sequence should be preserved, PDIR
change first.
--
Péter | {
"author": "=?UTF-8?Q?P=C3=A9ter_Ujfalusi?= <peter.ujfalusi@gmail.com>",
"date": "Mon, 2 Feb 2026 18:49:40 +0200",
"thread_id": "d7ed59c4-2262-4cd5-978f-e9e5c0e8a9a9@gmail.com.mbox.gz"
} |
lkml | [PATCH 0/4] ASoC: ti: davinci-mcasp: Add asynchronous mode support for McASP | This series adds asynchronous mode support to the McASP driver, which
enables independent configuration of bitclocks, frame sync, and audio
configurations between tx(playback) and rx(record). And achieves
simultaneous playback & record using different audio configurations.
It also adds two clean up patches to the McAS... | On 30/01/2026 07:10, Sen Wang wrote:
static void mcasp_start_rx(struct davinci_mcasp *mcasp)
In new code - while it might not match with old code - use producer
instead of master.
Otherwise it looks nice, I trust you have tested the sync and DIT mode.
With this nitpick addressed:
Acked-by: Peter Ujfalusi <peter.u... | {
"author": "=?UTF-8?Q?P=C3=A9ter_Ujfalusi?= <peter.ujfalusi@gmail.com>",
"date": "Mon, 2 Feb 2026 19:02:31 +0200",
"thread_id": "d7ed59c4-2262-4cd5-978f-e9e5c0e8a9a9@gmail.com.mbox.gz"
} |
lkml | [PATCH v4 0/3] targeted TLB sync IPIs for lockless page table walkers | When freeing or unsharing page tables we send an IPI to synchronize with
concurrent lockless page table walkers (e.g. GUP-fast). Today we broadcast
that IPI to all CPUs, which is costly on large machines and hurts RT
workloads[1].
This series makes those IPIs targeted. We track which CPUs are currently
doing a lockles... | From: Lance Yang <lance.yang@linux.dev>
Now that we have tlb_remove_table_sync_mm(), convert callers from
tlb_remove_table_sync_one() to enable targeted IPIs instead of broadcast.
Three callers updated:
1) collapse_huge_page() - after flushing the old PMD, only IPIs CPUs
walking this mm instead of all CPUs.
2) t... | {
"author": "Lance Yang <lance.yang@linux.dev>",
"date": "Mon, 2 Feb 2026 15:45:56 +0800",
"thread_id": "20260202074557.16544-1-lance.yang@linux.dev.mbox.gz"
} |
lkml | [PATCH v4 0/3] targeted TLB sync IPIs for lockless page table walkers | When freeing or unsharing page tables we send an IPI to synchronize with
concurrent lockless page table walkers (e.g. GUP-fast). Today we broadcast
that IPI to all CPUs, which is costly on large machines and hurts RT
workloads[1].
This series makes those IPIs targeted. We track which CPUs are currently
doing a lockles... | From: Lance Yang <lance.yang@linux.dev>
Currently, tlb_remove_table_sync_one() broadcasts IPIs to all CPUs to wait
for any concurrent lockless page table walkers (e.g., GUP-fast). This is
inefficient on systems with many CPUs, especially for RT workloads[1].
This patch introduces a per-CPU tracking mechanism to recor... | {
"author": "Lance Yang <lance.yang@linux.dev>",
"date": "Mon, 2 Feb 2026 15:45:55 +0800",
"thread_id": "20260202074557.16544-1-lance.yang@linux.dev.mbox.gz"
} |
lkml | [PATCH v4 0/3] targeted TLB sync IPIs for lockless page table walkers | When freeing or unsharing page tables we send an IPI to synchronize with
concurrent lockless page table walkers (e.g. GUP-fast). Today we broadcast
that IPI to all CPUs, which is costly on large machines and hurts RT
workloads[1].
This series makes those IPIs targeted. We track which CPUs are currently
doing a lockles... | From: Lance Yang <lance.yang@linux.dev>
When the TLB flush path already sends IPIs (e.g. native without INVLPGB,
or KVM), tlb_remove_table_sync_mm() does not need to send another round.
Add a property on pv_mmu_ops so each paravirt backend can indicate whether
its flush_tlb_multi sends real IPIs; if so, tlb_remove_ta... | {
"author": "Lance Yang <lance.yang@linux.dev>",
"date": "Mon, 2 Feb 2026 15:45:57 +0800",
"thread_id": "20260202074557.16544-1-lance.yang@linux.dev.mbox.gz"
} |
lkml | [PATCH v4 0/3] targeted TLB sync IPIs for lockless page table walkers | When freeing or unsharing page tables we send an IPI to synchronize with
concurrent lockless page table walkers (e.g. GUP-fast). Today we broadcast
that IPI to all CPUs, which is costly on large machines and hurts RT
workloads[1].
This series makes those IPIs targeted. We track which CPUs are currently
doing a lockles... | On Mon, Feb 02, 2026 at 03:45:55PM +0800, Lance Yang wrote:
What architecture, and that is acceptable?
One thing to try is something like:
xchg(this_cpu_ptr(&active_lockless_pt_walk_mm), mm);
That *might* be a little better on x86_64, on anything else you really
don't want to use this_cpu_() ops when you *know* I... | {
"author": "Peter Zijlstra <peterz@infradead.org>",
"date": "Mon, 2 Feb 2026 10:42:45 +0100",
"thread_id": "20260202074557.16544-1-lance.yang@linux.dev.mbox.gz"
} |
lkml | [PATCH v4 0/3] targeted TLB sync IPIs for lockless page table walkers | When freeing or unsharing page tables we send an IPI to synchronize with
concurrent lockless page table walkers (e.g. GUP-fast). Today we broadcast
that IPI to all CPUs, which is costly on large machines and hurts RT
workloads[1].
This series makes those IPIs targeted. We track which CPUs are currently
doing a lockles... | On Mon, Feb 02, 2026 at 03:45:54PM +0800, Lance Yang wrote:
I'm confused. This only happens when !PT_RECLAIM, because if PT_RECLAIM
__tlb_remove_table_one() actually uses RCU.
So why are you making things more expensive for no reason? | {
"author": "Peter Zijlstra <peterz@infradead.org>",
"date": "Mon, 2 Feb 2026 10:54:14 +0100",
"thread_id": "20260202074557.16544-1-lance.yang@linux.dev.mbox.gz"
} |
lkml | [PATCH v4 0/3] targeted TLB sync IPIs for lockless page table walkers | When freeing or unsharing page tables we send an IPI to synchronize with
concurrent lockless page table walkers (e.g. GUP-fast). Today we broadcast
that IPI to all CPUs, which is costly on large machines and hurts RT
workloads[1].
This series makes those IPIs targeted. We track which CPUs are currently
doing a lockles... | On Mon, 2 Feb 2026 10:54:14 +0100, Peter Zijlstra wrote:
You're right that when CONFIG_PT_RECLAIM is set, __tlb_remove_table_one()
uses call_rcu() and we never call any sync there — this series doesn't
touch that path.
In the !PT_RECLAIM table-free path (same __tlb_remove_table_one() branch
that calls tlb_remove_tabl... | {
"author": "Lance Yang <lance.yang@linux.dev>",
"date": "Mon, 2 Feb 2026 19:00:16 +0800",
"thread_id": "20260202074557.16544-1-lance.yang@linux.dev.mbox.gz"
} |
lkml | [PATCH v4 0/3] targeted TLB sync IPIs for lockless page table walkers | When freeing or unsharing page tables we send an IPI to synchronize with
concurrent lockless page table walkers (e.g. GUP-fast). Today we broadcast
that IPI to all CPUs, which is costly on large machines and hurts RT
workloads[1].
This series makes those IPIs targeted. We track which CPUs are currently
doing a lockles... | Hi Peter,
Thanks for taking time to review!
On 2026/2/2 17:42, Peter Zijlstra wrote:
x86-64.
I ran ./gup_bench which spawns 60 threads, each doing 500k GUP-fast
operations (pinning 8 pages per call) via the gup_test ioctl.
Results for pin pages:
- Before: avg 1.489s (10 runs)
- After: avg 1.533s (10 runs)
Given ... | {
"author": "Lance Yang <lance.yang@linux.dev>",
"date": "Mon, 2 Feb 2026 20:14:32 +0800",
"thread_id": "20260202074557.16544-1-lance.yang@linux.dev.mbox.gz"
} |
lkml | [PATCH v4 0/3] targeted TLB sync IPIs for lockless page table walkers | When freeing or unsharing page tables we send an IPI to synchronize with
concurrent lockless page table walkers (e.g. GUP-fast). Today we broadcast
that IPI to all CPUs, which is costly on large machines and hurts RT
workloads[1].
This series makes those IPIs targeted. We track which CPUs are currently
doing a lockles... | On Mon, Feb 02, 2026 at 07:00:16PM +0800, Lance Yang wrote:
Right, but if we can use full RCU for PT_RECLAIM, why can't we do so
unconditionally and not add overhead? | {
"author": "Peter Zijlstra <peterz@infradead.org>",
"date": "Mon, 2 Feb 2026 13:50:30 +0100",
"thread_id": "20260202074557.16544-1-lance.yang@linux.dev.mbox.gz"
} |
lkml | [PATCH v4 0/3] targeted TLB sync IPIs for lockless page table walkers | When freeing or unsharing page tables we send an IPI to synchronize with
concurrent lockless page table walkers (e.g. GUP-fast). Today we broadcast
that IPI to all CPUs, which is costly on large machines and hurts RT
workloads[1].
This series makes those IPIs targeted. We track which CPUs are currently
doing a lockles... | On Mon, Feb 02, 2026 at 08:14:32PM +0800, Lance Yang wrote:
No it doesn't; this is not how memory barriers work. | {
"author": "Peter Zijlstra <peterz@infradead.org>",
"date": "Mon, 2 Feb 2026 13:51:46 +0100",
"thread_id": "20260202074557.16544-1-lance.yang@linux.dev.mbox.gz"
} |
lkml | [PATCH v4 0/3] targeted TLB sync IPIs for lockless page table walkers | When freeing or unsharing page tables we send an IPI to synchronize with
concurrent lockless page table walkers (e.g. GUP-fast). Today we broadcast
that IPI to all CPUs, which is costly on large machines and hurts RT
workloads[1].
This series makes those IPIs targeted. We track which CPUs are currently
doing a lockles... | On 2026/2/2 20:50, Peter Zijlstra wrote:
The sync (IPI) is mainly needed for unshare (e.g. hugetlb) and collapse
(khugepaged) paths, regardless of whether table free uses RCU, IIUC. | {
"author": "Lance Yang <lance.yang@linux.dev>",
"date": "Mon, 2 Feb 2026 20:58:59 +0800",
"thread_id": "20260202074557.16544-1-lance.yang@linux.dev.mbox.gz"
} |
lkml | [PATCH v4 0/3] targeted TLB sync IPIs for lockless page table walkers | When freeing or unsharing page tables we send an IPI to synchronize with
concurrent lockless page table walkers (e.g. GUP-fast). Today we broadcast
that IPI to all CPUs, which is costly on large machines and hurts RT
workloads[1].
This series makes those IPIs targeted. We track which CPUs are currently
doing a lockles... | On 2026/2/2 20:58, Lance Yang wrote:
In addition: We need the sync when we modify page tables (e.g. unshare,
collapse), not only when we free them. RCU can defer freeing but does
not prevent lockless walkers from seeing concurrent in-place
modifications, so we need the IPI to synchronize with those walkers
first. | {
"author": "Lance Yang <lance.yang@linux.dev>",
"date": "Mon, 2 Feb 2026 21:07:10 +0800",
"thread_id": "20260202074557.16544-1-lance.yang@linux.dev.mbox.gz"
} |
lkml | [PATCH v4 0/3] targeted TLB sync IPIs for lockless page table walkers | When freeing or unsharing page tables we send an IPI to synchronize with
concurrent lockless page table walkers (e.g. GUP-fast). Today we broadcast
that IPI to all CPUs, which is costly on large machines and hurts RT
workloads[1].
This series makes those IPIs targeted. We track which CPUs are currently
doing a lockles... | On 2026/2/2 20:51, Peter Zijlstra wrote:
Hmm... we need MB rather than RMB on the sync side. Is that correct?
Walker:
[W]active_lockless_pt_walk_mm = mm -> MB -> [L]page-tables
Sync:
[W]page-tables -> MB -> [L]active_lockless_pt_walk_mm
Thanks,
Lance | {
"author": "Lance Yang <lance.yang@linux.dev>",
"date": "Mon, 2 Feb 2026 21:23:07 +0800",
"thread_id": "20260202074557.16544-1-lance.yang@linux.dev.mbox.gz"
} |
lkml | [PATCH v4 0/3] targeted TLB sync IPIs for lockless page table walkers | When freeing or unsharing page tables we send an IPI to synchronize with
concurrent lockless page table walkers (e.g. GUP-fast). Today we broadcast
that IPI to all CPUs, which is costly on large machines and hurts RT
workloads[1].
This series makes those IPIs targeted. We track which CPUs are currently
doing a lockles... | On Mon, Feb 02, 2026 at 09:07:10PM +0800, Lance Yang wrote:
Currently PT_RECLAIM=y has no IPI; are you saying that is broken? If
not, then why do we need this at all? | {
"author": "Peter Zijlstra <peterz@infradead.org>",
"date": "Mon, 2 Feb 2026 14:37:13 +0100",
"thread_id": "20260202074557.16544-1-lance.yang@linux.dev.mbox.gz"
} |
lkml | [PATCH v4 0/3] targeted TLB sync IPIs for lockless page table walkers | When freeing or unsharing page tables we send an IPI to synchronize with
concurrent lockless page table walkers (e.g. GUP-fast). Today we broadcast
that IPI to all CPUs, which is costly on large machines and hurts RT
workloads[1].
This series makes those IPIs targeted. We track which CPUs are currently
doing a lockles... | On Mon, Feb 02, 2026 at 09:23:07PM +0800, Lance Yang wrote:
This can work -- but only if the walker and sync touch the same
page-table address.
Now, typically I would imagine they both share the p4d/pud address at
the very least, right? | {
"author": "Peter Zijlstra <peterz@infradead.org>",
"date": "Mon, 2 Feb 2026 14:42:33 +0100",
"thread_id": "20260202074557.16544-1-lance.yang@linux.dev.mbox.gz"
} |
lkml | [PATCH v4 0/3] targeted TLB sync IPIs for lockless page table walkers | When freeing or unsharing page tables we send an IPI to synchronize with
concurrent lockless page table walkers (e.g. GUP-fast). Today we broadcast
that IPI to all CPUs, which is costly on large machines and hurts RT
workloads[1].
This series makes those IPIs targeted. We track which CPUs are currently
doing a lockles... | On 2026/2/2 21:42, Peter Zijlstra wrote:
Thanks. I think I see the confusion ...
To be clear, the goal is not to make the walker see page-table writes
through the
MB pairing, but to wait for any concurrent lockless page table walkers
to finish.
The flow is:
1) Page tables are modified
2) TLB flush is done
3) Read... | {
"author": "Lance Yang <lance.yang@linux.dev>",
"date": "Mon, 2 Feb 2026 22:28:47 +0800",
"thread_id": "20260202074557.16544-1-lance.yang@linux.dev.mbox.gz"
} |
lkml | [PATCH v4 0/3] targeted TLB sync IPIs for lockless page table walkers | When freeing or unsharing page tables we send an IPI to synchronize with
concurrent lockless page table walkers (e.g. GUP-fast). Today we broadcast
that IPI to all CPUs, which is costly on large machines and hurts RT
workloads[1].
This series makes those IPIs targeted. We track which CPUs are currently
doing a lockles... | On 2026/2/2 21:37, Peter Zijlstra wrote:
PT_RECLAIM=y does have IPI for unshare/collapse — those paths call
tlb_flush_unshared_tables() (for hugetlb unshare) and collapse_huge_page()
(in khugepaged collapse), which already send IPIs today (broadcast to all
CPUs via tlb_remove_table_sync_one()).
What PT_RECLAIM=y does... | {
"author": "Lance Yang <lance.yang@linux.dev>",
"date": "Mon, 2 Feb 2026 22:37:39 +0800",
"thread_id": "20260202074557.16544-1-lance.yang@linux.dev.mbox.gz"
} |
lkml | [PATCH v4 0/3] targeted TLB sync IPIs for lockless page table walkers | When freeing or unsharing page tables we send an IPI to synchronize with
concurrent lockless page table walkers (e.g. GUP-fast). Today we broadcast
that IPI to all CPUs, which is costly on large machines and hurts RT
workloads[1].
This series makes those IPIs targeted. We track which CPUs are currently
doing a lockles... | On Mon, Feb 02, 2026 at 10:37:39PM +0800, Lance Yang wrote:
Oh bah, reading is hard. I had missed they had more table_sync_one() calls,
rather than remove_table_one().
So you *can* replace table_sync_one() with rcu_sync(), that will provide
the same guarantees. Its just a 'little' bit slower on the update side,
but d... | {
"author": "Peter Zijlstra <peterz@infradead.org>",
"date": "Mon, 2 Feb 2026 16:09:57 +0100",
"thread_id": "20260202074557.16544-1-lance.yang@linux.dev.mbox.gz"
} |
lkml | [PATCH v4 0/3] targeted TLB sync IPIs for lockless page table walkers | When freeing or unsharing page tables we send an IPI to synchronize with
concurrent lockless page table walkers (e.g. GUP-fast). Today we broadcast
that IPI to all CPUs, which is costly on large machines and hurts RT
workloads[1].
This series makes those IPIs targeted. We track which CPUs are currently
doing a lockles... | On 2026/2/2 23:09, Peter Zijlstra wrote:
Yep, we could replace the IPI with synchronize_rcu() on the sync side:
- Currently: TLB flush → send IPI → wait for walkers to finish
- With synchronize_rcu(): TLB flush → synchronize_rcu() -> waits for
grace period
Lockless walkers (e.g. GUP-fast) use local_irq_disable();
... | {
"author": "Lance Yang <lance.yang@linux.dev>",
"date": "Mon, 2 Feb 2026 23:52:31 +0800",
"thread_id": "20260202074557.16544-1-lance.yang@linux.dev.mbox.gz"
} |
lkml | [PATCH v4 0/3] targeted TLB sync IPIs for lockless page table walkers | When freeing or unsharing page tables we send an IPI to synchronize with
concurrent lockless page table walkers (e.g. GUP-fast). Today we broadcast
that IPI to all CPUs, which is costly on large machines and hurts RT
workloads[1].
This series makes those IPIs targeted. We track which CPUs are currently
doing a lockles... | On 2/2/26 04:14, Lance Yang wrote:
I thought the big databases were really sensitive to GUP-fast latency.
They like big systems, too. Won't they howl when this finally hits their
testing?
Also, two of the "write" side here are:
* collapse_huge_page() (khugepaged)
* tlb_remove_table() (in an "-ENOMEM" path)
Those ... | {
"author": "Dave Hansen <dave.hansen@intel.com>",
"date": "Mon, 2 Feb 2026 08:20:13 -0800",
"thread_id": "20260202074557.16544-1-lance.yang@linux.dev.mbox.gz"
} |
lkml | [PATCH 0/7] i3c: mipi-i3c-hci-pci: Enable IBI while runtime suspended for Intel controllers | Hi
Here are patches related to enabling IBI while runtime suspended for Intel
controllers.
Intel LPSS I3C controllers can wake from runtime suspend to receive
in-band interrupts (IBIs).
It is non-trivial to implement because the parent PCI device has 2 I3C bus
instances (MIPI I3C HCI Multi-Bus Instance capability) r... | Set d3hot_delay to 0 for Intel controllers because a delay is not needed.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
---
drivers/i3c/master/mipi-i3c-hci/mipi-i3c-hci-pci.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/i3c/master/mipi-i3c-hci/mipi-i3c-hci-pci.c b/drivers/i3c/master/mipi-i3c-h... | {
"author": "Adrian Hunter <adrian.hunter@intel.com>",
"date": "Thu, 29 Jan 2026 20:18:35 +0200",
"thread_id": "20260129181841.130864-1-adrian.hunter@intel.com.mbox.gz"
} |
lkml | [PATCH 0/7] i3c: mipi-i3c-hci-pci: Enable IBI while runtime suspended for Intel controllers | Hi
Here are patches related to enabling IBI while runtime suspended for Intel
controllers.
Intel LPSS I3C controllers can wake from runtime suspend to receive
in-band interrupts (IBIs).
It is non-trivial to implement because the parent PCI device has 2 I3C bus
instances (MIPI I3C HCI Multi-Bus Instance capability) r... | Some I3C controller drivers need runtime PM to operate on a device other
than the parent device. To support that, add an rpm_dev pointer to
struct i3c_master_controller so drivers can specify which device should
be used for runtime power management.
If a driver does not set rpm_dev explicitly, default to using the pa... | {
"author": "Adrian Hunter <adrian.hunter@intel.com>",
"date": "Thu, 29 Jan 2026 20:18:36 +0200",
"thread_id": "20260129181841.130864-1-adrian.hunter@intel.com.mbox.gz"
} |
lkml | [PATCH 0/7] i3c: mipi-i3c-hci-pci: Enable IBI while runtime suspended for Intel controllers | Hi
Here are patches related to enabling IBI while runtime suspended for Intel
controllers.
Intel LPSS I3C controllers can wake from runtime suspend to receive
in-band interrupts (IBIs).
It is non-trivial to implement because the parent PCI device has 2 I3C bus
instances (MIPI I3C HCI Multi-Bus Instance capability) r... | When an IBI can be received after the controller is
pm_runtime_put_autosuspend()'ed, the interrupt may occur just before the
device is auto‑suspended. In such cases, the runtime PM core may not see
any recent activity and may suspend the device earlier than intended.
Mark the controller as last busy whenever an IBI i... | {
"author": "Adrian Hunter <adrian.hunter@intel.com>",
"date": "Thu, 29 Jan 2026 20:18:37 +0200",
"thread_id": "20260129181841.130864-1-adrian.hunter@intel.com.mbox.gz"
} |
lkml | [PATCH 0/7] i3c: mipi-i3c-hci-pci: Enable IBI while runtime suspended for Intel controllers | Hi
Here are patches related to enabling IBI while runtime suspended for Intel
controllers.
Intel LPSS I3C controllers can wake from runtime suspend to receive
in-band interrupts (IBIs).
It is non-trivial to implement because the parent PCI device has 2 I3C bus
instances (MIPI I3C HCI Multi-Bus Instance capability) r... | Some I3C controllers can be automatically runtime-resumed in order to
handle in-band interrupts (IBIs), meaning that runtime suspend does not
need to be blocked when IBIs are enabled.
For example, a PCI-attached controller in a low-power state may generate
a Power Management Event (PME) when the SDA line is pulled low... | {
"author": "Adrian Hunter <adrian.hunter@intel.com>",
"date": "Thu, 29 Jan 2026 20:18:38 +0200",
"thread_id": "20260129181841.130864-1-adrian.hunter@intel.com.mbox.gz"
} |
lkml | [PATCH 0/7] i3c: mipi-i3c-hci-pci: Enable IBI while runtime suspended for Intel controllers | Hi
Here are patches related to enabling IBI while runtime suspended for Intel
controllers.
Intel LPSS I3C controllers can wake from runtime suspend to receive
in-band interrupts (IBIs).
It is non-trivial to implement because the parent PCI device has 2 I3C bus
instances (MIPI I3C HCI Multi-Bus Instance capability) r... | Some platforms implement the MIPI I3C HCI Multi-Bus Instance capability,
where a single parent device hosts multiple I3C controller instances. In
such designs, the parent - not the individual child instances - may need to
coordinate runtime PM so that all controllers enter low-power states
together, and all runtime su... | {
"author": "Adrian Hunter <adrian.hunter@intel.com>",
"date": "Thu, 29 Jan 2026 20:18:39 +0200",
"thread_id": "20260129181841.130864-1-adrian.hunter@intel.com.mbox.gz"
} |
lkml | [PATCH 0/7] i3c: mipi-i3c-hci-pci: Enable IBI while runtime suspended for Intel controllers | Hi
Here are patches related to enabling IBI while runtime suspended for Intel
controllers.
Intel LPSS I3C controllers can wake from runtime suspend to receive
in-band interrupts (IBIs).
It is non-trivial to implement because the parent PCI device has 2 I3C bus
instances (MIPI I3C HCI Multi-Bus Instance capability) r... | Intel LPSS I3C controllers can wake from runtime suspend to receive
in-band interrupts (IBIs), and they also implement the MIPI I3C HCI
Multi-Bus Instance capability. When multiple I3C bus instances share the
same PCI wakeup, the PCI parent must coordinate runtime PM so that all
instances suspend together and their mi... | {
"author": "Adrian Hunter <adrian.hunter@intel.com>",
"date": "Thu, 29 Jan 2026 20:18:41 +0200",
"thread_id": "20260129181841.130864-1-adrian.hunter@intel.com.mbox.gz"
} |
lkml | [PATCH 0/7] i3c: mipi-i3c-hci-pci: Enable IBI while runtime suspended for Intel controllers | Hi
Here are patches related to enabling IBI while runtime suspended for Intel
controllers.
Intel LPSS I3C controllers can wake from runtime suspend to receive
in-band interrupts (IBIs).
It is non-trivial to implement because the parent PCI device has 2 I3C bus
instances (MIPI I3C HCI Multi-Bus Instance capability) r... | Some platforms implement the MIPI I3C HCI Multi-Bus Instance capability,
where a single parent device hosts multiple I3C controller instances. In
such designs, the parent - not the individual child instances - may need to
coordinate runtime PM so that all controllers enter low-power states
together, and all runtime su... | {
"author": "Adrian Hunter <adrian.hunter@intel.com>",
"date": "Thu, 29 Jan 2026 20:18:40 +0200",
"thread_id": "20260129181841.130864-1-adrian.hunter@intel.com.mbox.gz"
} |
lkml | [PATCH 0/7] i3c: mipi-i3c-hci-pci: Enable IBI while runtime suspended for Intel controllers | Hi
Here are patches related to enabling IBI while runtime suspended for Intel
controllers.
Intel LPSS I3C controllers can wake from runtime suspend to receive
in-band interrupts (IBIs).
It is non-trivial to implement because the parent PCI device has 2 I3C bus
instances (MIPI I3C HCI Multi-Bus Instance capability) r... | On Thu, Jan 29, 2026 at 08:18:35PM +0200, Adrian Hunter wrote:
Reviewed-by: Frank Li <Frank.Li@nxp.com> | {
"author": "Frank Li <Frank.li@nxp.com>",
"date": "Thu, 29 Jan 2026 14:43:45 -0500",
"thread_id": "20260129181841.130864-1-adrian.hunter@intel.com.mbox.gz"
} |
lkml | [PATCH 0/7] i3c: mipi-i3c-hci-pci: Enable IBI while runtime suspended for Intel controllers | Hi
Here are patches related to enabling IBI while runtime suspended for Intel
controllers.
Intel LPSS I3C controllers can wake from runtime suspend to receive
in-band interrupts (IBIs).
It is non-trivial to implement because the parent PCI device has 2 I3C bus
instances (MIPI I3C HCI Multi-Bus Instance capability) r... | On Thu, Jan 29, 2026 at 08:18:37PM +0200, Adrian Hunter wrote:
look like this can't resolve problem. pm_runtime_mark_last_busy() just
change dev->power.last_busy. If suspend before it, nothing happen.
irq use thread irq, in irq thread call pm_runtime_resume() if needs.
And this function call by irq handle, just put ... | {
"author": "Frank Li <Frank.li@nxp.com>",
"date": "Thu, 29 Jan 2026 14:56:01 -0500",
"thread_id": "20260129181841.130864-1-adrian.hunter@intel.com.mbox.gz"
} |
lkml | [PATCH 0/7] i3c: mipi-i3c-hci-pci: Enable IBI while runtime suspended for Intel controllers | Hi
Here are patches related to enabling IBI while runtime suspended for Intel
controllers.
Intel LPSS I3C controllers can wake from runtime suspend to receive
in-band interrupts (IBIs).
It is non-trivial to implement because the parent PCI device has 2 I3C bus
instances (MIPI I3C HCI Multi-Bus Instance capability) r... | On Thu, Jan 29, 2026 at 08:18:39PM +0200, Adrian Hunter wrote:
Does your hardware support recieve IBI when runtime suspend?
Frank | {
"author": "Frank Li <Frank.li@nxp.com>",
"date": "Thu, 29 Jan 2026 15:00:14 -0500",
"thread_id": "20260129181841.130864-1-adrian.hunter@intel.com.mbox.gz"
} |
lkml | [PATCH 0/7] i3c: mipi-i3c-hci-pci: Enable IBI while runtime suspended for Intel controllers | Hi
Here are patches related to enabling IBI while runtime suspended for Intel
controllers.
Intel LPSS I3C controllers can wake from runtime suspend to receive
in-band interrupts (IBIs).
It is non-trivial to implement because the parent PCI device has 2 I3C bus
instances (MIPI I3C HCI Multi-Bus Instance capability) r... | On 29/01/2026 22:00, Frank Li wrote:
When runtime suspended (in D3), the hardware first triggers a Power Management
Event (PME) when the SDA line is pulled low to signal the START condition of an IBI.
The PCI subsystem will then runtime-resume the device. When the bus is enabled,
the clock is started and the IBI is r... | {
"author": "Adrian Hunter <adrian.hunter@intel.com>",
"date": "Thu, 29 Jan 2026 22:28:14 +0200",
"thread_id": "20260129181841.130864-1-adrian.hunter@intel.com.mbox.gz"
} |
lkml | [PATCH 0/7] i3c: mipi-i3c-hci-pci: Enable IBI while runtime suspended for Intel controllers | Hi
Here are patches related to enabling IBI while runtime suspended for Intel
controllers.
Intel LPSS I3C controllers can wake from runtime suspend to receive
in-band interrupts (IBIs).
It is non-trivial to implement because the parent PCI device has 2 I3C bus
instances (MIPI I3C HCI Multi-Bus Instance capability) r... | On 29/01/2026 21:56, Frank Li wrote:
It should be effective.
rpm_suspend() recalculates the autosuspend expiry time based on
last_busy (see pm_runtime_autosuspend_expiration()) and restarts
the timer is it is in the future.
Just premature runtime suspension inconsistent with autosuspend_delay. | {
"author": "Adrian Hunter <adrian.hunter@intel.com>",
"date": "Thu, 29 Jan 2026 22:42:32 +0200",
"thread_id": "20260129181841.130864-1-adrian.hunter@intel.com.mbox.gz"
} |
lkml | [PATCH 0/7] i3c: mipi-i3c-hci-pci: Enable IBI while runtime suspended for Intel controllers | Hi
Here are patches related to enabling IBI while runtime suspended for Intel
controllers.
Intel LPSS I3C controllers can wake from runtime suspend to receive
in-band interrupts (IBIs).
It is non-trivial to implement because the parent PCI device has 2 I3C bus
instances (MIPI I3C HCI Multi-Bus Instance capability) r... | On Thu, Jan 29, 2026 at 10:42:32PM +0200, Adrian Hunter wrote:
CPU 0 CPU 1
1. rpm_suspend() 2. pm_runtime_mark_last_busy(master->rpm_dev)
if 2 happen before 1, it can extend suspend. 2 happen after 1, it should
do nothing.
Frank | {
"author": "Frank Li <Frank.li@nxp.com>",
"date": "Thu, 29 Jan 2026 15:55:40 -0500",
"thread_id": "20260129181841.130864-1-adrian.hunter@intel.com.mbox.gz"
} |
lkml | [PATCH 0/7] i3c: mipi-i3c-hci-pci: Enable IBI while runtime suspended for Intel controllers | Hi
Here are patches related to enabling IBI while runtime suspended for Intel
controllers.
Intel LPSS I3C controllers can wake from runtime suspend to receive
in-band interrupts (IBIs).
It is non-trivial to implement because the parent PCI device has 2 I3C bus
instances (MIPI I3C HCI Multi-Bus Instance capability) r... | On Thu, Jan 29, 2026 at 10:28:14PM +0200, Adrian Hunter wrote:
It align my assumption, why need complex solution.
SDA->PME->IRQ should handle by hardware, so irq handle queue IBI to working
queue.
IBI work will try do transfer, which will call runtime resume(), then
transfer data.
What's issue?
Frank | {
"author": "Frank Li <Frank.li@nxp.com>",
"date": "Thu, 29 Jan 2026 16:00:20 -0500",
"thread_id": "20260129181841.130864-1-adrian.hunter@intel.com.mbox.gz"
} |
lkml | [PATCH 0/7] i3c: mipi-i3c-hci-pci: Enable IBI while runtime suspended for Intel controllers | Hi
Here are patches related to enabling IBI while runtime suspended for Intel
controllers.
Intel LPSS I3C controllers can wake from runtime suspend to receive
in-band interrupts (IBIs).
It is non-trivial to implement because the parent PCI device has 2 I3C bus
instances (MIPI I3C HCI Multi-Bus Instance capability) r... | On 29/01/2026 23:00, Frank Li wrote:
The PME indicates I3C START (SDA line pulled low). The controller is
in a low power state unable to operate the bus. At this point it is not
known what I3C device has pulled down the SDA line, or even if it is an
IBI since it is indistinguishable from hot-join at this point.
The... | {
"author": "Adrian Hunter <adrian.hunter@intel.com>",
"date": "Fri, 30 Jan 2026 09:00:33 +0200",
"thread_id": "20260129181841.130864-1-adrian.hunter@intel.com.mbox.gz"
} |
lkml | [PATCH 0/7] i3c: mipi-i3c-hci-pci: Enable IBI while runtime suspended for Intel controllers | Hi
Here are patches related to enabling IBI while runtime suspended for Intel
controllers.
Intel LPSS I3C controllers can wake from runtime suspend to receive
in-band interrupts (IBIs).
It is non-trivial to implement because the parent PCI device has 2 I3C bus
instances (MIPI I3C HCI Multi-Bus Instance capability) r... | On 29/01/2026 22:55, Frank Li wrote:
2 happening after 1 is a separate issue. It will never happen
in the wakeup case because the wakeup does a runtime resume:
pm_runtime_put_autosuspend()
IBI -> pm_runtime_mark_last_busy()
another IBI -> pm_runtime_mark_last_busy() and so on
<autosuspend_delay finally elapses>
... | {
"author": "Adrian Hunter <adrian.hunter@intel.com>",
"date": "Fri, 30 Jan 2026 09:48:07 +0200",
"thread_id": "20260129181841.130864-1-adrian.hunter@intel.com.mbox.gz"
} |
lkml | [PATCH 0/7] i3c: mipi-i3c-hci-pci: Enable IBI while runtime suspended for Intel controllers | Hi
Here are patches related to enabling IBI while runtime suspended for Intel
controllers.
Intel LPSS I3C controllers can wake from runtime suspend to receive
in-band interrupts (IBIs).
It is non-trivial to implement because the parent PCI device has 2 I3C bus
instances (MIPI I3C HCI Multi-Bus Instance capability) r... | On Fri, Jan 30, 2026 at 09:00:33AM +0200, Adrian Hunter wrote:
One instance 1 suspend, instance 2 running, PME is inactive, what's happen
if instance 1 request IBI?
IBI will be missed?
Does PME active auto by hardware or need software config?
Frank | {
"author": "Frank Li <Frank.li@nxp.com>",
"date": "Fri, 30 Jan 2026 10:04:24 -0500",
"thread_id": "20260129181841.130864-1-adrian.hunter@intel.com.mbox.gz"
} |
lkml | [PATCH 0/7] i3c: mipi-i3c-hci-pci: Enable IBI while runtime suspended for Intel controllers | Hi
Here are patches related to enabling IBI while runtime suspended for Intel
controllers.
Intel LPSS I3C controllers can wake from runtime suspend to receive
in-band interrupts (IBIs).
It is non-trivial to implement because the parent PCI device has 2 I3C bus
instances (MIPI I3C HCI Multi-Bus Instance capability) r... | On 30/01/2026 17:04, Frank Li wrote:
Nothing will happen. Instance 1 I3C bus is not operational and there can
be no PME when the PCI device is not in a low power state (D3hot)
Possibly not if instance 1 is eventually resumed and the I3C device
requesting the IBI has not yet given up.
PCI devices (hardware) advert... | {
"author": "Adrian Hunter <adrian.hunter@intel.com>",
"date": "Fri, 30 Jan 2026 18:34:37 +0200",
"thread_id": "20260129181841.130864-1-adrian.hunter@intel.com.mbox.gz"
} |
lkml | [PATCH 0/7] i3c: mipi-i3c-hci-pci: Enable IBI while runtime suspended for Intel controllers | Hi
Here are patches related to enabling IBI while runtime suspended for Intel
controllers.
Intel LPSS I3C controllers can wake from runtime suspend to receive
in-band interrupts (IBIs).
It is non-trivial to implement because the parent PCI device has 2 I3C bus
instances (MIPI I3C HCI Multi-Bus Instance capability) r... | On Fri, Jan 30, 2026 at 06:34:37PM +0200, Adrian Hunter wrote:
Okay, I think I understand your situation, let me check patch again.
Frank | {
"author": "Frank Li <Frank.li@nxp.com>",
"date": "Fri, 30 Jan 2026 12:11:19 -0500",
"thread_id": "20260129181841.130864-1-adrian.hunter@intel.com.mbox.gz"
} |
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