source large_stringclasses 2
values | subject large_stringclasses 112
values | code large_stringclasses 112
values | critique large_stringlengths 61 3.04M ⌀ | metadata dict |
|---|---|---|---|---|
lkml | [PATCH v3 00/47] arm_mpam: Add KVM/arm64 and resctrl glue code | This new version of the mpam missing pieces has no major rework from the
previous version. It's mainly small corrections and code tidying based on
review and things I spotted along the way. To be able to merge this we need
review from more people and people to start testing on their platforms and
giving some Tested-by ... | Hi Ben,
On Mon, Jan 12, 2026 at 5:59 PM Ben Horgan <ben.horgan@arm.com> wrote:
Like before, I applied the patches and successfully booted a kernel on
a baremetal Google Cloud C4A instance. I was able to confirm that the
resources we expect were present and I was able to successfully run
the monitor assignment test ca... | {
"author": "Peter Newman <peternewman@google.com>",
"date": "Thu, 15 Jan 2026 12:14:19 +0100",
"thread_id": "ca45ea06-53fa-4010-86c6-66213243b636@nvidia.com.mbox.gz"
} |
lkml | [PATCH v3 00/47] arm_mpam: Add KVM/arm64 and resctrl glue code | This new version of the mpam missing pieces has no major rework from the
previous version. It's mainly small corrections and code tidying based on
review and things I spotted along the way. To be able to merge this we need
review from more people and people to start testing on their platforms and
giving some Tested-by ... | Hi Marc,
On 1/15/26 09:05, Marc Zyngier wrote:
The new MPAM arch code always configures kernel space MPAM configuration
in tandem, same value to MPAM0_EL1 and MPAM1_EL1 (will access MPAM2_EL2
in vhe).
For the cpu part see
PATCH v3 07 arm64: mpam: Re-initialise MPAM regs when CPU comes online
and for context switchin... | {
"author": "Ben Horgan <ben.horgan@arm.com>",
"date": "Thu, 15 Jan 2026 11:14:36 +0000",
"thread_id": "ca45ea06-53fa-4010-86c6-66213243b636@nvidia.com.mbox.gz"
} |
lkml | [PATCH v3 00/47] arm_mpam: Add KVM/arm64 and resctrl glue code | This new version of the mpam missing pieces has no major rework from the
previous version. It's mainly small corrections and code tidying based on
review and things I spotted along the way. To be able to merge this we need
review from more people and people to start testing on their platforms and
giving some Tested-by ... | Hi Peter,
On 1/15/26 11:14, Peter Newman wrote:
[...]
Thanks for the testing!
Ben | {
"author": "Ben Horgan <ben.horgan@arm.com>",
"date": "Thu, 15 Jan 2026 11:36:47 +0000",
"thread_id": "ca45ea06-53fa-4010-86c6-66213243b636@nvidia.com.mbox.gz"
} |
lkml | [PATCH v3 00/47] arm_mpam: Add KVM/arm64 and resctrl glue code | This new version of the mpam missing pieces has no major rework from the
previous version. It's mainly small corrections and code tidying based on
review and things I spotted along the way. To be able to merge this we need
review from more people and people to start testing on their platforms and
giving some Tested-by ... | On Thu, 15 Jan 2026 14:47:28 +0800
Gavin Shan <gshan@redhat.com> wrote:
I commented on the nitpick.
That is a non obvious include chain that we should not rely on.
Please keep the headers and continue to follow include what you use
style (with exceptions when a given header is clearly documented as always includin... | {
"author": "Jonathan Cameron <jonathan.cameron@huawei.com>",
"date": "Thu, 15 Jan 2026 12:09:23 +0000",
"thread_id": "ca45ea06-53fa-4010-86c6-66213243b636@nvidia.com.mbox.gz"
} |
lkml | [PATCH v3 00/47] arm_mpam: Add KVM/arm64 and resctrl glue code | This new version of the mpam missing pieces has no major rework from the
previous version. It's mainly small corrections and code tidying based on
review and things I spotted along the way. To be able to merge this we need
review from more people and people to start testing on their platforms and
giving some Tested-by ... | Hi Zeng,
+CC Babu (Comments on PLZA)
On 1/14/26 06:51, Zeng Heng wrote:
Makes sense, thanks for these two observations.
I wonder if this would be possible in AMD PLZA as well. Babu?
Yes, I watched a recording of that. :)
Will do. Apologies for not doing this earlier and thank you for the
promise of testing and... | {
"author": "Ben Horgan <ben.horgan@arm.com>",
"date": "Thu, 15 Jan 2026 14:37:31 +0000",
"thread_id": "ca45ea06-53fa-4010-86c6-66213243b636@nvidia.com.mbox.gz"
} |
lkml | [PATCH v3 00/47] arm_mpam: Add KVM/arm64 and resctrl glue code | This new version of the mpam missing pieces has no major rework from the
previous version. It's mainly small corrections and code tidying based on
review and things I spotted along the way. To be able to merge this we need
review from more people and people to start testing on their platforms and
giving some Tested-by ... | Hi Reinette,
On 1/13/26 23:14, Reinette Chatre wrote:
I'll test against this.
[...]
Thanks for bringing this to my attention. mpam_resctrl_monitor_init()
won't be called for all events known to resctrl as
mpam_resctrl_pick_counters() will only set a class for the 3 that MPAM
knows about. Still, it is probably best ... | {
"author": "Ben Horgan <ben.horgan@arm.com>",
"date": "Thu, 15 Jan 2026 15:43:54 +0000",
"thread_id": "ca45ea06-53fa-4010-86c6-66213243b636@nvidia.com.mbox.gz"
} |
lkml | [PATCH v3 00/47] arm_mpam: Add KVM/arm64 and resctrl glue code | This new version of the mpam missing pieces has no major rework from the
previous version. It's mainly small corrections and code tidying based on
review and things I spotted along the way. To be able to merge this we need
review from more people and people to start testing on their platforms and
giving some Tested-by ... | Hi Ben,
On Mon, Jan 12, 2026 at 6:02 PM Ben Horgan <ben.horgan@arm.com> wrote:
Are remote memory accesses not cached? How do we know an MBWU monitor
residing on a cache won't count remote traffic?
Thanks,
-Peter | {
"author": "Peter Newman <peternewman@google.com>",
"date": "Thu, 15 Jan 2026 16:49:20 +0100",
"thread_id": "ca45ea06-53fa-4010-86c6-66213243b636@nvidia.com.mbox.gz"
} |
lkml | [PATCH v3 00/47] arm_mpam: Add KVM/arm64 and resctrl glue code | This new version of the mpam missing pieces has no major rework from the
previous version. It's mainly small corrections and code tidying based on
review and things I spotted along the way. To be able to merge this we need
review from more people and people to start testing on their platforms and
giving some Tested-by ... | Hi Shaopeng,
On 1/15/26 10:05, Shaopeng Tan (Fujitsu) wrote:
The intent of returning 0 here is that if csu is not supported on this
class then there is nothing to do and hence no error.
Yes, the check is redundant and can be removed. (If it were to stay it
should be moved to be before call get_cpu_cacheinfo_level()... | {
"author": "Ben Horgan <ben.horgan@arm.com>",
"date": "Thu, 15 Jan 2026 16:02:47 +0000",
"thread_id": "ca45ea06-53fa-4010-86c6-66213243b636@nvidia.com.mbox.gz"
} |
lkml | [PATCH v3 00/47] arm_mpam: Add KVM/arm64 and resctrl glue code | This new version of the mpam missing pieces has no major rework from the
previous version. It's mainly small corrections and code tidying based on
review and things I spotted along the way. To be able to merge this we need
review from more people and people to start testing on their platforms and
giving some Tested-by ... | On Mon, Jan 12, 2026 at 04:58:33PM +0000, Ben Horgan wrote:
Since we have an isb() already, does it make any difference if we write
MPAM0 before the barrier? Similar question for other places where we
write these two registers.
At some point, we should go through __switch_to() and coalesce the isbs
into fewer as we k... | {
"author": "Catalin Marinas <catalin.marinas@arm.com>",
"date": "Thu, 15 Jan 2026 17:58:15 +0000",
"thread_id": "ca45ea06-53fa-4010-86c6-66213243b636@nvidia.com.mbox.gz"
} |
lkml | [PATCH v3 00/47] arm_mpam: Add KVM/arm64 and resctrl glue code | This new version of the mpam missing pieces has no major rework from the
previous version. It's mainly small corrections and code tidying based on
review and things I spotted along the way. To be able to merge this we need
review from more people and people to start testing on their platforms and
giving some Tested-by ... | On Mon, Jan 12, 2026 at 04:58:30PM +0000, Ben Horgan wrote:
Acked-by: Catalin Marinas <catalin.marinas@arm.com> | {
"author": "Catalin Marinas <catalin.marinas@arm.com>",
"date": "Thu, 15 Jan 2026 17:59:05 +0000",
"thread_id": "ca45ea06-53fa-4010-86c6-66213243b636@nvidia.com.mbox.gz"
} |
lkml | [PATCH v3 00/47] arm_mpam: Add KVM/arm64 and resctrl glue code | This new version of the mpam missing pieces has no major rework from the
previous version. It's mainly small corrections and code tidying based on
review and things I spotted along the way. To be able to merge this we need
review from more people and people to start testing on their platforms and
giving some Tested-by ... | On Mon, Jan 12, 2026 at 04:58:34PM +0000, Ben Horgan wrote:
Is this comment about priority inversion no longer valid? I see thread
switching sets the same value for both MPAM0 and MPAM1 registers but I
couldn't find an explanation why this is now better when it wasn't
before.
MPAM1 will also be inherited by IRQ handl... | {
"author": "Catalin Marinas <catalin.marinas@arm.com>",
"date": "Thu, 15 Jan 2026 18:14:09 +0000",
"thread_id": "ca45ea06-53fa-4010-86c6-66213243b636@nvidia.com.mbox.gz"
} |
lkml | [PATCH v3 00/47] arm_mpam: Add KVM/arm64 and resctrl glue code | This new version of the mpam missing pieces has no major rework from the
previous version. It's mainly small corrections and code tidying based on
review and things I spotted along the way. To be able to merge this we need
review from more people and people to start testing on their platforms and
giving some Tested-by ... | On Mon, Jan 12, 2026 at 04:58:35PM +0000, Ben Horgan wrote:
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> | {
"author": "Catalin Marinas <catalin.marinas@arm.com>",
"date": "Thu, 15 Jan 2026 18:16:49 +0000",
"thread_id": "ca45ea06-53fa-4010-86c6-66213243b636@nvidia.com.mbox.gz"
} |
lkml | [PATCH v3 00/47] arm_mpam: Add KVM/arm64 and resctrl glue code | This new version of the mpam missing pieces has no major rework from the
previous version. It's mainly small corrections and code tidying based on
review and things I spotted along the way. To be able to merge this we need
review from more people and people to start testing on their platforms and
giving some Tested-by ... | On Mon, Jan 12, 2026 at 04:58:36PM +0000, Ben Horgan wrote:
This looks fine unless we decide to save/restore them in the low-level
suspend/resume functions.
--
Catalin | {
"author": "Catalin Marinas <catalin.marinas@arm.com>",
"date": "Thu, 15 Jan 2026 18:20:02 +0000",
"thread_id": "ca45ea06-53fa-4010-86c6-66213243b636@nvidia.com.mbox.gz"
} |
lkml | [PATCH v3 00/47] arm_mpam: Add KVM/arm64 and resctrl glue code | This new version of the mpam missing pieces has no major rework from the
previous version. It's mainly small corrections and code tidying based on
review and things I spotted along the way. To be able to merge this we need
review from more people and people to start testing on their platforms and
giving some Tested-by ... | Hi Ben,
On 1/15/26 7:43 AM, Ben Horgan wrote:
...
Please note that this documentation has been refactored (without changing its
meaning). The above quoted text is specific to L3 monitoring and with the
addition of telemetry monitoring the relevant text now reads:
The upper bound for how many "CTRL_MON" + "MON" can b... | {
"author": "Reinette Chatre <reinette.chatre@intel.com>",
"date": "Thu, 15 Jan 2026 10:54:45 -0800",
"thread_id": "ca45ea06-53fa-4010-86c6-66213243b636@nvidia.com.mbox.gz"
} |
lkml | [PATCH v3 00/47] arm_mpam: Add KVM/arm64 and resctrl glue code | This new version of the mpam missing pieces has no major rework from the
previous version. It's mainly small corrections and code tidying based on
review and things I spotted along the way. To be able to merge this we need
review from more people and people to start testing on their platforms and
giving some Tested-by ... | On Mon, Jan 12, 2026 at 04:58:37PM +0000, Ben Horgan wrote:
Do we know for sure that system_supports_sme() returns true at this
point (if SME supported)? Digging into the code, system_supports_sme()
uses alternative_has_cap_unlikely() which relies on instruction
patching. setup_system_capabilities(), IIUC, patches the... | {
"author": "Catalin Marinas <catalin.marinas@arm.com>",
"date": "Thu, 15 Jan 2026 19:08:47 +0000",
"thread_id": "ca45ea06-53fa-4010-86c6-66213243b636@nvidia.com.mbox.gz"
} |
lkml | [PATCH v3 00/47] arm_mpam: Add KVM/arm64 and resctrl glue code | This new version of the mpam missing pieces has no major rework from the
previous version. It's mainly small corrections and code tidying based on
review and things I spotted along the way. To be able to merge this we need
review from more people and people to start testing on their platforms and
giving some Tested-by ... | On Mon, Jan 12, 2026 at 04:58:38PM +0000, Ben Horgan wrote:
Isn't this function, together with mpam_thread_switch(), in an enclosing
#ifdef already?
--
Catalin | {
"author": "Catalin Marinas <catalin.marinas@arm.com>",
"date": "Thu, 15 Jan 2026 19:13:45 +0000",
"thread_id": "ca45ea06-53fa-4010-86c6-66213243b636@nvidia.com.mbox.gz"
} |
lkml | [PATCH v3 00/47] arm_mpam: Add KVM/arm64 and resctrl glue code | This new version of the mpam missing pieces has no major rework from the
previous version. It's mainly small corrections and code tidying based on
review and things I spotted along the way. To be able to merge this we need
review from more people and people to start testing on their platforms and
giving some Tested-by ... | On Mon, Jan 12, 2026 at 04:59:06PM +0000, Ben Horgan wrote:
Acked-by: Catalin Marinas <catalin.marinas@arm.com> | {
"author": "Catalin Marinas <catalin.marinas@arm.com>",
"date": "Thu, 15 Jan 2026 19:16:48 +0000",
"thread_id": "ca45ea06-53fa-4010-86c6-66213243b636@nvidia.com.mbox.gz"
} |
lkml | [PATCH v3 00/47] arm_mpam: Add KVM/arm64 and resctrl glue code | This new version of the mpam missing pieces has no major rework from the
previous version. It's mainly small corrections and code tidying based on
review and things I spotted along the way. To be able to merge this we need
review from more people and people to start testing on their platforms and
giving some Tested-by ... | Hi, Shanker and Ben,
On 1/12/26 08:59, Ben Horgan wrote:
When MBW_MIN=1, min mem bw can be very low when contention. This may
drop mem access performance. Is it possible to set MBW_MIN bigger so
that ensure the floor of mem access is high?
Thanks.
-Fenghua | {
"author": "Fenghua Yu <fenghuay@nvidia.com>",
"date": "Thu, 15 Jan 2026 15:20:55 -0800",
"thread_id": "ca45ea06-53fa-4010-86c6-66213243b636@nvidia.com.mbox.gz"
} |
lkml | [PATCH v3 00/47] arm_mpam: Add KVM/arm64 and resctrl glue code | This new version of the mpam missing pieces has no major rework from the
previous version. It's mainly small corrections and code tidying based on
review and things I spotted along the way. To be able to merge this we need
review from more people and people to start testing on their platforms and
giving some Tested-by ... | Hi Reinette, Peter,
On 1/15/26 18:54, Reinette Chatre wrote:
Ok, I don't really see another option.
The motivation for this is that to me
Just thinking about it now but the "mon_id_includes_control_id" option
seems the best to me as it is a single bit option that along with
"num_rmids" let's you know which monitor ... | {
"author": "Ben Horgan <ben.horgan@arm.com>",
"date": "Fri, 16 Jan 2026 10:29:01 +0000",
"thread_id": "ca45ea06-53fa-4010-86c6-66213243b636@nvidia.com.mbox.gz"
} |
lkml | [PATCH v3 00/47] arm_mpam: Add KVM/arm64 and resctrl glue code | This new version of the mpam missing pieces has no major rework from the
previous version. It's mainly small corrections and code tidying based on
review and things I spotted along the way. To be able to merge this we need
review from more people and people to start testing on their platforms and
giving some Tested-by ... | Hello Ben,
$ echo "default" | sudo tee /sys/fs/resctrl/info/L3_MON/mbm_assign_mode
default
tee: /sys/fs/resctrl/info/L3_MON/mbm_assign_mode:Invalid argument
"return -EOPNOTSUPP;" might be better.
Best regards,
Shaopeng TAN | {
"author": "\"Shaopeng Tan (Fujitsu)\" <tan.shaopeng@fujitsu.com>",
"date": "Fri, 16 Jan 2026 10:34:27 +0000",
"thread_id": "ca45ea06-53fa-4010-86c6-66213243b636@nvidia.com.mbox.gz"
} |
lkml | [PATCH v3 00/47] arm_mpam: Add KVM/arm64 and resctrl glue code | This new version of the mpam missing pieces has no major rework from the
previous version. It's mainly small corrections and code tidying based on
review and things I spotted along the way. To be able to merge this we need
review from more people and people to start testing on their platforms and
giving some Tested-by ... | Hello Ben,
I ran the MPAM driver on NVIDIA's Grace machine, and it seems to be working fine.
Tested-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com> | {
"author": "\"Shaopeng Tan (Fujitsu)\" <tan.shaopeng@fujitsu.com>",
"date": "Fri, 16 Jan 2026 10:47:40 +0000",
"thread_id": "ca45ea06-53fa-4010-86c6-66213243b636@nvidia.com.mbox.gz"
} |
lkml | [PATCH v3 00/47] arm_mpam: Add KVM/arm64 and resctrl glue code | This new version of the mpam missing pieces has no major rework from the
previous version. It's mainly small corrections and code tidying based on
review and things I spotted along the way. To be able to merge this we need
review from more people and people to start testing on their platforms and
giving some Tested-by ... | Hi Shaopeng,
On 1/16/26 10:34, Shaopeng Tan (Fujitsu) wrote:
[...]
I'll keep this as -EINVAL in the case when 'enable' matches the current mode
and change it to return 0 when there is nothing to change. This will match the
behaviour once this is handled in resctrl. See the outcome of the discussion on
this resctrl p... | {
"author": "Ben Horgan <ben.horgan@arm.com>",
"date": "Fri, 16 Jan 2026 11:04:24 +0000",
"thread_id": "ca45ea06-53fa-4010-86c6-66213243b636@nvidia.com.mbox.gz"
} |
lkml | [PATCH v3 00/47] arm_mpam: Add KVM/arm64 and resctrl glue code | This new version of the mpam missing pieces has no major rework from the
previous version. It's mainly small corrections and code tidying based on
review and things I spotted along the way. To be able to merge this we need
review from more people and people to start testing on their platforms and
giving some Tested-by ... | Hi Shaopeng,
On 1/16/26 10:47, Shaopeng Tan (Fujitsu) wrote:
Thanks for the testing!
Ben | {
"author": "Ben Horgan <ben.horgan@arm.com>",
"date": "Fri, 16 Jan 2026 11:05:57 +0000",
"thread_id": "ca45ea06-53fa-4010-86c6-66213243b636@nvidia.com.mbox.gz"
} |
lkml | [PATCH v3 00/47] arm_mpam: Add KVM/arm64 and resctrl glue code | This new version of the mpam missing pieces has no major rework from the
previous version. It's mainly small corrections and code tidying based on
review and things I spotted along the way. To be able to merge this we need
review from more people and people to start testing on their platforms and
giving some Tested-by ... | On Mon, Jan 12, 2026 at 04:58:29PM +0000, Ben Horgan wrote:
After discussing privately, I can see how test__props_mismatch() can
end up with unaligned atomics on the mmap_props::features array. Happy to
pick it up for 6.19 (probably the first patch as well, though that's
harmless).
Is there a Fixes tag here for futur... | {
"author": "Catalin Marinas <catalin.marinas@arm.com>",
"date": "Fri, 16 Jan 2026 11:57:25 +0000",
"thread_id": "ca45ea06-53fa-4010-86c6-66213243b636@nvidia.com.mbox.gz"
} |
lkml | [PATCH v3 00/47] arm_mpam: Add KVM/arm64 and resctrl glue code | This new version of the mpam missing pieces has no major rework from the
previous version. It's mainly small corrections and code tidying based on
review and things I spotted along the way. To be able to merge this we need
review from more people and people to start testing on their platforms and
giving some Tested-by ... | Hi Catalin,
On 1/16/26 11:57, Catalin Marinas wrote:
Yes please.
Yes, the mpam_set/clear macros were introduced in
Fixes: 8c90dc68a5de ("arm_mpam: Probe the hardware features resctrl supports")
Thanks,
Ben | {
"author": "Ben Horgan <ben.horgan@arm.com>",
"date": "Fri, 16 Jan 2026 12:02:06 +0000",
"thread_id": "ca45ea06-53fa-4010-86c6-66213243b636@nvidia.com.mbox.gz"
} |
lkml | [PATCH v3 00/47] arm_mpam: Add KVM/arm64 and resctrl glue code | This new version of the mpam missing pieces has no major rework from the
previous version. It's mainly small corrections and code tidying based on
review and things I spotted along the way. To be able to merge this we need
review from more people and people to start testing on their platforms and
giving some Tested-by ... | On 1/16/26 12:02, Ben Horgan wrote:
The mpam_set_clear() actually comes after in:
c10ca83a7783 arm_mpam: Merge supported features during mpam_enable() into mpam_class
but I think the fixes below is still the correct one as it is where we could
first start seeing the problem.
Thanks,
Ben | {
"author": "Ben Horgan <ben.horgan@arm.com>",
"date": "Fri, 16 Jan 2026 12:12:53 +0000",
"thread_id": "ca45ea06-53fa-4010-86c6-66213243b636@nvidia.com.mbox.gz"
} |
lkml | [PATCH v3 00/47] arm_mpam: Add KVM/arm64 and resctrl glue code | This new version of the mpam missing pieces has no major rework from the
previous version. It's mainly small corrections and code tidying based on
review and things I spotted along the way. To be able to merge this we need
review from more people and people to start testing on their platforms and
giving some Tested-by ... | On Mon, 12 Jan 2026 16:58:27 +0000, Ben Horgan wrote:
Applied to arm64 (for-next/fixes), thanks!
[01/47] arm_mpam: Remove duplicate linux/srcu.h header
https://git.kernel.org/arm64/c/b5a69c486921
[02/47] arm_mpam: Use non-atomic bitops when modifying feature bitmap
https://git.kernel.org/arm64/c/b9f5c... | {
"author": "Catalin Marinas <catalin.marinas@arm.com>",
"date": "Fri, 16 Jan 2026 15:47:15 +0000",
"thread_id": "ca45ea06-53fa-4010-86c6-66213243b636@nvidia.com.mbox.gz"
} |
lkml | [PATCH v3 00/47] arm_mpam: Add KVM/arm64 and resctrl glue code | This new version of the mpam missing pieces has no major rework from the
previous version. It's mainly small corrections and code tidying based on
review and things I spotted along the way. To be able to merge this we need
review from more people and people to start testing on their platforms and
giving some Tested-by ... | On Fri, Jan 16, 2026 at 12:12:53PM +0000, Ben Horgan wrote:
Yes, I left the original as that's the one first introducing the atomic
bitops on this structure.
--
Catalin | {
"author": "Catalin Marinas <catalin.marinas@arm.com>",
"date": "Fri, 16 Jan 2026 15:51:02 +0000",
"thread_id": "ca45ea06-53fa-4010-86c6-66213243b636@nvidia.com.mbox.gz"
} |
lkml | [PATCH v3 00/47] arm_mpam: Add KVM/arm64 and resctrl glue code | This new version of the mpam missing pieces has no major rework from the
previous version. It's mainly small corrections and code tidying based on
review and things I spotted along the way. To be able to merge this we need
review from more people and people to start testing on their platforms and
giving some Tested-by ... | On 1/13/26 12:58 AM, Ben Horgan wrote:
The L3 cache partitioning and MBW (soft) limiting works fine on NVidia's grace-hopper machine.
Tested-by: Gavin Shan <gshan@redhat.com>
Thanks,
Gavin | {
"author": "Gavin Shan <gshan@redhat.com>",
"date": "Mon, 19 Jan 2026 09:30:32 +0800",
"thread_id": "ca45ea06-53fa-4010-86c6-66213243b636@nvidia.com.mbox.gz"
} |
lkml | [PATCH v3 00/47] arm_mpam: Add KVM/arm64 and resctrl glue code | This new version of the mpam missing pieces has no major rework from the
previous version. It's mainly small corrections and code tidying based on
review and things I spotted along the way. To be able to merge this we need
review from more people and people to start testing on their platforms and
giving some Tested-by ... | Hi Ben,
On 1/13/26 12:58 AM, Ben Horgan wrote:
mpam_register_requestor() is exposed until CONFIG_ARM64_MPAM_DRIVER is set.
CONFIG_ARM64_MPAM_DRIVER and CONFIG_ARM64_MPAM can be different until PATCH[39/47]
is applied. So we need PATCH[39/47] to be applied prior to this patch so that
mpam_register_requestor() is alway... | {
"author": "Gavin Shan <gshan@redhat.com>",
"date": "Mon, 19 Jan 2026 14:37:46 +0800",
"thread_id": "ca45ea06-53fa-4010-86c6-66213243b636@nvidia.com.mbox.gz"
} |
lkml | [PATCH v3 00/47] arm_mpam: Add KVM/arm64 and resctrl glue code | This new version of the mpam missing pieces has no major rework from the
previous version. It's mainly small corrections and code tidying based on
review and things I spotted along the way. To be able to merge this we need
review from more people and people to start testing on their platforms and
giving some Tested-by ... | On 1/13/26 12:58 AM, Ben Horgan wrote:
Reviewed-by: Gavin Shan <gshan@redhat.com> | {
"author": "Gavin Shan <gshan@redhat.com>",
"date": "Mon, 19 Jan 2026 14:40:59 +0800",
"thread_id": "ca45ea06-53fa-4010-86c6-66213243b636@nvidia.com.mbox.gz"
} |
lkml | [PATCH v3 00/47] arm_mpam: Add KVM/arm64 and resctrl glue code | This new version of the mpam missing pieces has no major rework from the
previous version. It's mainly small corrections and code tidying based on
review and things I spotted along the way. To be able to merge this we need
review from more people and people to start testing on their platforms and
giving some Tested-by ... | Hi Ben,
On 1/13/26 12:58 AM, Ben Horgan wrote:
One question below...
Need we ensure MPAM capability exists in the hardware before the notifier is registerred?
Otherwise, mpam_pm_notifier() can accesses SYS_MPAM0_EL1 and SYS_MPAM1_EL1 system registers
which may not supported by the hardware.
Thanks,
Gavin | {
"author": "Gavin Shan <gshan@redhat.com>",
"date": "Mon, 19 Jan 2026 14:50:16 +0800",
"thread_id": "ca45ea06-53fa-4010-86c6-66213243b636@nvidia.com.mbox.gz"
} |
lkml | [PATCH v3 00/47] arm_mpam: Add KVM/arm64 and resctrl glue code | This new version of the mpam missing pieces has no major rework from the
previous version. It's mainly small corrections and code tidying based on
review and things I spotted along the way. To be able to merge this we need
review from more people and people to start testing on their platforms and
giving some Tested-by ... | Hi Ben,
On 1/13/26 12:58 AM, Ben Horgan wrote:
One nitpick below...
Reviewed-by: Gavin Shan <gshan@redhat.com>
{ } is missed here.
Thanks,
Gavin | {
"author": "Gavin Shan <gshan@redhat.com>",
"date": "Mon, 19 Jan 2026 14:51:40 +0800",
"thread_id": "ca45ea06-53fa-4010-86c6-66213243b636@nvidia.com.mbox.gz"
} |
lkml | [PATCH v3 00/47] arm_mpam: Add KVM/arm64 and resctrl glue code | This new version of the mpam missing pieces has no major rework from the
previous version. It's mainly small corrections and code tidying based on
review and things I spotted along the way. To be able to merge this we need
review from more people and people to start testing on their platforms and
giving some Tested-by ... | On 1/16/26 3:13 AM, Catalin Marinas wrote:
I think Catalin is correct that this ifdef inside mpam_set_task_partid_pmg()
can be dropped.
Thanks,
Gavin | {
"author": "Gavin Shan <gshan@redhat.com>",
"date": "Mon, 19 Jan 2026 14:56:46 +0800",
"thread_id": "ca45ea06-53fa-4010-86c6-66213243b636@nvidia.com.mbox.gz"
} |
lkml | [PATCH v3 00/47] arm_mpam: Add KVM/arm64 and resctrl glue code | This new version of the mpam missing pieces has no major rework from the
previous version. It's mainly small corrections and code tidying based on
review and things I spotted along the way. To be able to merge this we need
review from more people and people to start testing on their platforms and
giving some Tested-by ... | Hi Ben,
On 1/13/26 12:58 AM, Ben Horgan wrote:
Nitpick: Alignment issues in the lines for 2nd/3rd/4th FIELD_PREP().
return FIELD_PREP(...) |
FIELD_PREP(...) |
FIELD_PREP(...) |
FIELD_PREP(...);
per_cpu(arm64_mpam_default) won't be reachable until CONFIG_ARM64_MPAM is set.
S... | {
"author": "Gavin Shan <gshan@redhat.com>",
"date": "Mon, 19 Jan 2026 15:01:41 +0800",
"thread_id": "ca45ea06-53fa-4010-86c6-66213243b636@nvidia.com.mbox.gz"
} |
lkml | [PATCH v3 00/47] arm_mpam: Add KVM/arm64 and resctrl glue code | This new version of the mpam missing pieces has no major rework from the
previous version. It's mainly small corrections and code tidying based on
review and things I spotted along the way. To be able to merge this we need
review from more people and people to start testing on their platforms and
giving some Tested-by ... | Hi Ben,
On 1/13/26 12:58 AM, Ben Horgan wrote:
A warning reported by checkpatch.pl like below.
WARNING: Missing a blank line after declarations
#117: FILE: drivers/resctrl/mpam_resctrl.c:375:
+ struct mpam_component *victim_iter;
+ cpumask_var_t __free(free_cpumask_var) tmp_cpumask;
Besides, it'd better to initiali... | {
"author": "Gavin Shan <gshan@redhat.com>",
"date": "Mon, 19 Jan 2026 19:53:25 +0800",
"thread_id": "ca45ea06-53fa-4010-86c6-66213243b636@nvidia.com.mbox.gz"
} |
lkml | [PATCH v3 00/47] arm_mpam: Add KVM/arm64 and resctrl glue code | This new version of the mpam missing pieces has no major rework from the
previous version. It's mainly small corrections and code tidying based on
review and things I spotted along the way. To be able to merge this we need
review from more people and people to start testing on their platforms and
giving some Tested-by ... | Hi Ben,
On 1/13/26 12:58 AM, Ben Horgan wrote:
A warning reported by checkpatch.pl as below.
WARNING: Missing a blank line after declarations
#84: FILE: drivers/resctrl/mpam_resctrl.c:607:
+ size_t array_size = num_mbwu_mon * sizeof(int);
+ int *array __free(kfree) = kmalloc(array_size, GFP_KERNEL);
Thanks,
Gavin | {
"author": "Gavin Shan <gshan@redhat.com>",
"date": "Mon, 19 Jan 2026 19:57:38 +0800",
"thread_id": "ca45ea06-53fa-4010-86c6-66213243b636@nvidia.com.mbox.gz"
} |
lkml | [PATCH v3 00/47] arm_mpam: Add KVM/arm64 and resctrl glue code | This new version of the mpam missing pieces has no major rework from the
previous version. It's mainly small corrections and code tidying based on
review and things I spotted along the way. To be able to merge this we need
review from more people and people to start testing on their platforms and
giving some Tested-by ... | Hi Peter,
On 15/01/2026 15:49, Peter Newman wrote:
It will, yes you get double counting. Is forbidding both mbm_total and mbm_local preferable?
I think this comes from 'total' in mbm_total not really having the obvious meaning of the
word:
If I have CPUs in NUMA-A and no memory controllers, then NUMA-B has no CPUs,... | {
"author": "James Morse <james.morse@arm.com>",
"date": "Mon, 19 Jan 2026 12:04:10 +0000",
"thread_id": "ca45ea06-53fa-4010-86c6-66213243b636@nvidia.com.mbox.gz"
} |
lkml | [PATCH v3 00/47] arm_mpam: Add KVM/arm64 and resctrl glue code | This new version of the mpam missing pieces has no major rework from the
previous version. It's mainly small corrections and code tidying based on
review and things I spotted along the way. To be able to merge this we need
review from more people and people to start testing on their platforms and
giving some Tested-by ... | On 1/13/26 12:59 AM, Ben Horgan wrote:
An error reported by checkpatch.pl as below.
ERROR: Macros with complex values should be enclosed in parentheses
#135: FILE: drivers/resctrl/mpam_internal.h:238:
+#define MPAM_IIDR_MATCH_ONE FIELD_PREP_CONST(MPAMF_IIDR_PRODUCTID, 0xfff) | \
+ FIELD_PREP_CONST(MPAMF_IIDR_VAR... | {
"author": "Gavin Shan <gshan@redhat.com>",
"date": "Mon, 19 Jan 2026 20:14:44 +0800",
"thread_id": "ca45ea06-53fa-4010-86c6-66213243b636@nvidia.com.mbox.gz"
} |
lkml | [PATCH v3 00/47] arm_mpam: Add KVM/arm64 and resctrl glue code | This new version of the mpam missing pieces has no major rework from the
previous version. It's mainly small corrections and code tidying based on
review and things I spotted along the way. To be able to merge this we need
review from more people and people to start testing on their platforms and
giving some Tested-by ... | On 1/13/26 12:59 AM, Ben Horgan wrote:
An error reported by checkpatch.pl as below.
ERROR: Macros with complex values should be enclosed in parentheses
#205: FILE: drivers/resctrl/mpam_internal.h:247:
+#define MPAM_IIDR_NVIDIA_T241 FIELD_PREP_CONST(MPAMF_IIDR_PRODUCTID, 0x241) | \
+ FIELD_PREP_CONST(MPAMF_IIDR_V... | {
"author": "Gavin Shan <gshan@redhat.com>",
"date": "Mon, 19 Jan 2026 20:16:30 +0800",
"thread_id": "ca45ea06-53fa-4010-86c6-66213243b636@nvidia.com.mbox.gz"
} |
lkml | [PATCH v3 00/47] arm_mpam: Add KVM/arm64 and resctrl glue code | This new version of the mpam missing pieces has no major rework from the
previous version. It's mainly small corrections and code tidying based on
review and things I spotted along the way. To be able to merge this we need
review from more people and people to start testing on their platforms and
giving some Tested-by ... | On 1/13/26 12:59 AM, Ben Horgan wrote:
An error reported by checkpatch.pl as below.
ERROR: Macros with complex values should be enclosed in parentheses
#105: FILE: drivers/resctrl/mpam_internal.h:255:
+#define MPAM_IIDR_ARM_CMN_650 FIELD_PREP_CONST(MPAMF_IIDR_PRODUCTID, 0) | \
+ FIELD_PREP_CONST(MPAMF_IIDR_VARIA... | {
"author": "Gavin Shan <gshan@redhat.com>",
"date": "Mon, 19 Jan 2026 20:18:50 +0800",
"thread_id": "ca45ea06-53fa-4010-86c6-66213243b636@nvidia.com.mbox.gz"
} |
lkml | [PATCH v3 00/47] arm_mpam: Add KVM/arm64 and resctrl glue code | This new version of the mpam missing pieces has no major rework from the
previous version. It's mainly small corrections and code tidying based on
review and things I spotted along the way. To be able to merge this we need
review from more people and people to start testing on their platforms and
giving some Tested-by ... | Hi Catalin,
On 1/15/26 17:58, Catalin Marinas wrote:
The reason for the isb() placement is to document that it's not required
for the MPAM0_EL1. All instructions running at EL1take their MPAM
configuration from MPAM1_EL1. This includes LDTR and STTR as you asked
about in a different thread.
It's done this way as it... | {
"author": "Ben Horgan <ben.horgan@arm.com>",
"date": "Mon, 19 Jan 2026 12:23:13 +0000",
"thread_id": "ca45ea06-53fa-4010-86c6-66213243b636@nvidia.com.mbox.gz"
} |
lkml | [PATCH v3 00/47] arm_mpam: Add KVM/arm64 and resctrl glue code | This new version of the mpam missing pieces has no major rework from the
previous version. It's mainly small corrections and code tidying based on
review and things I spotted along the way. To be able to merge this we need
review from more people and people to start testing on their platforms and
giving some Tested-by ... | Hi James,
On Mon, Jan 19, 2026 at 1:04 PM James Morse <james.morse@arm.com> wrote:
Our software is going off the definition from the Intel SDM:
"This event monitors the L3 external bandwidth satisfied by the local
memory. In most platforms that support this event, L3 requests are
likely serviced by a memory system w... | {
"author": "Peter Newman <peternewman@google.com>",
"date": "Mon, 19 Jan 2026 13:47:52 +0100",
"thread_id": "ca45ea06-53fa-4010-86c6-66213243b636@nvidia.com.mbox.gz"
} |
lkml | [PATCH v3 00/47] arm_mpam: Add KVM/arm64 and resctrl glue code | This new version of the mpam missing pieces has no major rework from the
previous version. It's mainly small corrections and code tidying based on
review and things I spotted along the way. To be able to merge this we need
review from more people and people to start testing on their platforms and
giving some Tested-by ... | Hi Catalin,
On 1/15/26 18:14, Catalin Marinas wrote:
Yes, will drop it.
I see thread
I touch on it in the cover letter. It is the way it is done for x86 and
so sensible to make it the default. All partids are usable from
user-space and user-space can't bypass MPAM controls by doing the work
in the kernel.
There i... | {
"author": "Ben Horgan <ben.horgan@arm.com>",
"date": "Mon, 19 Jan 2026 13:38:11 +0000",
"thread_id": "ca45ea06-53fa-4010-86c6-66213243b636@nvidia.com.mbox.gz"
} |
lkml | [PATCH v3 00/47] arm_mpam: Add KVM/arm64 and resctrl glue code | This new version of the mpam missing pieces has no major rework from the
previous version. It's mainly small corrections and code tidying based on
review and things I spotted along the way. To be able to merge this we need
review from more people and people to start testing on their platforms and
giving some Tested-by ... | Hi Catalin,
On 1/15/26 19:08, Catalin Marinas wrote:
I'll switch to cpus_have_cap().
Thanks,
Ben | {
"author": "Ben Horgan <ben.horgan@arm.com>",
"date": "Mon, 19 Jan 2026 13:40:18 +0000",
"thread_id": "ca45ea06-53fa-4010-86c6-66213243b636@nvidia.com.mbox.gz"
} |
lkml | [PATCH v3 00/47] arm_mpam: Add KVM/arm64 and resctrl glue code | This new version of the mpam missing pieces has no major rework from the
previous version. It's mainly small corrections and code tidying based on
review and things I spotted along the way. To be able to merge this we need
review from more people and people to start testing on their platforms and
giving some Tested-by ... | Hi Gavin,
On 1/19/26 11:53, Gavin Shan wrote:
[...]
I expect this is because __free() declarations don't need to be at the
top of a scope and so checkpatch doesn't treat them as normal
declarations. I don't think anything needs changing here.
Yep, I'll update.
Thanks,
Ben | {
"author": "Ben Horgan <ben.horgan@arm.com>",
"date": "Mon, 19 Jan 2026 13:53:23 +0000",
"thread_id": "ca45ea06-53fa-4010-86c6-66213243b636@nvidia.com.mbox.gz"
} |
lkml | [PATCH v3 00/47] arm_mpam: Add KVM/arm64 and resctrl glue code | This new version of the mpam missing pieces has no major rework from the
previous version. It's mainly small corrections and code tidying based on
review and things I spotted along the way. To be able to merge this we need
review from more people and people to start testing on their platforms and
giving some Tested-by ... | Hi Gavin, Jonathan,
On 1/15/26 12:09, Jonathan Cameron wrote:
Keeping the includes here makes sense to me too. Gavin, are you ok with
keeping this as is?
Thanks,
Ben | {
"author": "Ben Horgan <ben.horgan@arm.com>",
"date": "Mon, 19 Jan 2026 14:00:07 +0000",
"thread_id": "ca45ea06-53fa-4010-86c6-66213243b636@nvidia.com.mbox.gz"
} |
lkml | [PATCH v3 00/47] arm_mpam: Add KVM/arm64 and resctrl glue code | This new version of the mpam missing pieces has no major rework from the
previous version. It's mainly small corrections and code tidying based on
review and things I spotted along the way. To be able to merge this we need
review from more people and people to start testing on their platforms and
giving some Tested-by ... | Hi Catalin,
On 1/19/26 13:38, Ben Horgan wrote:
Ah, that's done in the patch already. Also, we can't treat 0 as special
without taking it away from userspace and then we're down a partid and
there might be that many.
Thanks,
Ben | {
"author": "Ben Horgan <ben.horgan@arm.com>",
"date": "Mon, 19 Jan 2026 14:22:13 +0000",
"thread_id": "ca45ea06-53fa-4010-86c6-66213243b636@nvidia.com.mbox.gz"
} |
lkml | [PATCH v3 00/47] arm_mpam: Add KVM/arm64 and resctrl glue code | This new version of the mpam missing pieces has no major rework from the
previous version. It's mainly small corrections and code tidying based on
review and things I spotted along the way. To be able to merge this we need
review from more people and people to start testing on their platforms and
giving some Tested-by ... | Hi Gavin,
On 1/19/26 06:37, Gavin Shan wrote:
I've split out the part of PATCH[39/47] that removes the CONFIG_EXPERT
restriction and put it before this patch. With that CONFIG_ARM64_MPAM
will unconditionally select CONFIG_ARM64_MPAM_DRIVER.
Thanks,
Ben | {
"author": "Ben Horgan <ben.horgan@arm.com>",
"date": "Mon, 19 Jan 2026 14:49:38 +0000",
"thread_id": "ca45ea06-53fa-4010-86c6-66213243b636@nvidia.com.mbox.gz"
} |
lkml | [PATCH v3 00/47] arm_mpam: Add KVM/arm64 and resctrl glue code | This new version of the mpam missing pieces has no major rework from the
previous version. It's mainly small corrections and code tidying based on
review and things I spotted along the way. To be able to merge this we need
review from more people and people to start testing on their platforms and
giving some Tested-by ... | Hi Gavin,
On 1/19/26 06:50, Gavin Shan wrote:
Ah yes, I'll add a system_supports_mpam() check here.
Thanks,
Ben | {
"author": "Ben Horgan <ben.horgan@arm.com>",
"date": "Mon, 19 Jan 2026 15:08:39 +0000",
"thread_id": "ca45ea06-53fa-4010-86c6-66213243b636@nvidia.com.mbox.gz"
} |
lkml | [PATCH v3 00/47] arm_mpam: Add KVM/arm64 and resctrl glue code | This new version of the mpam missing pieces has no major rework from the
previous version. It's mainly small corrections and code tidying based on
review and things I spotted along the way. To be able to merge this we need
review from more people and people to start testing on their platforms and
giving some Tested-by ... | Hi Gavin,
On 1/19/26 06:51, Gavin Shan wrote:
Addded.
Thanks,
Ben | {
"author": "Ben Horgan <ben.horgan@arm.com>",
"date": "Mon, 19 Jan 2026 15:31:34 +0000",
"thread_id": "ca45ea06-53fa-4010-86c6-66213243b636@nvidia.com.mbox.gz"
} |
lkml | [PATCH v3 00/47] arm_mpam: Add KVM/arm64 and resctrl glue code | This new version of the mpam missing pieces has no major rework from the
previous version. It's mainly small corrections and code tidying based on
review and things I spotted along the way. To be able to merge this we need
review from more people and people to start testing on their platforms and
giving some Tested-by ... | Hi Catalin,
On 1/15/26 19:13, Catalin Marinas wrote:
Yes, I'll remove the inner #ifdef.
Thanks,
Ben | {
"author": "Ben Horgan <ben.horgan@arm.com>",
"date": "Mon, 19 Jan 2026 15:47:07 +0000",
"thread_id": "ca45ea06-53fa-4010-86c6-66213243b636@nvidia.com.mbox.gz"
} |
lkml | [PATCH v3 00/47] arm_mpam: Add KVM/arm64 and resctrl glue code | This new version of the mpam missing pieces has no major rework from the
previous version. It's mainly small corrections and code tidying based on
review and things I spotted along the way. To be able to merge this we need
review from more people and people to start testing on their platforms and
giving some Tested-by ... | Hi Gavin,
On 1/19/26 07:01, Gavin Shan wrote:
Sure, I'll align these.
I'll move the #ifdef CONFIG_ARM64_MPAM up to cover these.
Thanks,
Ben | {
"author": "Ben Horgan <ben.horgan@arm.com>",
"date": "Mon, 19 Jan 2026 15:49:05 +0000",
"thread_id": "ca45ea06-53fa-4010-86c6-66213243b636@nvidia.com.mbox.gz"
} |
lkml | [PATCH v3 00/47] arm_mpam: Add KVM/arm64 and resctrl glue code | This new version of the mpam missing pieces has no major rework from the
previous version. It's mainly small corrections and code tidying based on
review and things I spotted along the way. To be able to merge this we need
review from more people and people to start testing on their platforms and
giving some Tested-by ... | Hi Reinette,
On 1/13/26 16:49, Reinette Chatre wrote:
Yeah, that leaks the memory and the offline call is unnecessary.
Yes.
Indeed.
Yes, it's missing.
I've reworked the code to move the resctrl_online_*() calls further up
so there is less to do on error, added a kfree(dom) and made the
ctrl_mon cleanup after the mo... | {
"author": "Ben Horgan <ben.horgan@arm.com>",
"date": "Mon, 19 Jan 2026 17:20:51 +0000",
"thread_id": "ca45ea06-53fa-4010-86c6-66213243b636@nvidia.com.mbox.gz"
} |
lkml | [PATCH v3 00/47] arm_mpam: Add KVM/arm64 and resctrl glue code | This new version of the mpam missing pieces has no major rework from the
previous version. It's mainly small corrections and code tidying based on
review and things I spotted along the way. To be able to merge this we need
review from more people and people to start testing on their platforms and
giving some Tested-by ... | Hi Gavin,
On 1/19/26 11:57, Gavin Shan wrote:
Similarly to the other blank line checkpatch.pl warning I expect this is
to do with how it handles the __free() annotation. I'm not intending to
change this code unless there is some style guideline that I've missed
or other reason to do so.
Thanks,
Ben | {
"author": "Ben Horgan <ben.horgan@arm.com>",
"date": "Mon, 19 Jan 2026 20:27:48 +0000",
"thread_id": "ca45ea06-53fa-4010-86c6-66213243b636@nvidia.com.mbox.gz"
} |
lkml | [PATCH v3 00/47] arm_mpam: Add KVM/arm64 and resctrl glue code | This new version of the mpam missing pieces has no major rework from the
previous version. It's mainly small corrections and code tidying based on
review and things I spotted along the way. To be able to merge this we need
review from more people and people to start testing on their platforms and
giving some Tested-by ... | Hi Shaopeng,
On 1/16/26 11:04, Ben Horgan wrote:
Actually, resctl_arch_cntr_assign_set() only gets called on an attempt
to change the value so I'll keep it as is.
Thanks,
Ben | {
"author": "Ben Horgan <ben.horgan@arm.com>",
"date": "Mon, 19 Jan 2026 20:34:06 +0000",
"thread_id": "ca45ea06-53fa-4010-86c6-66213243b636@nvidia.com.mbox.gz"
} |
lkml | [PATCH v3 00/47] arm_mpam: Add KVM/arm64 and resctrl glue code | This new version of the mpam missing pieces has no major rework from the
previous version. It's mainly small corrections and code tidying based on
review and things I spotted along the way. To be able to merge this we need
review from more people and people to start testing on their platforms and
giving some Tested-by ... | Hi Gavin,
On 1/19/26 12:14, Gavin Shan wrote:
That's a real error. Fixed.
Thanks,
Ben | {
"author": "Ben Horgan <ben.horgan@arm.com>",
"date": "Mon, 19 Jan 2026 20:48:45 +0000",
"thread_id": "ca45ea06-53fa-4010-86c6-66213243b636@nvidia.com.mbox.gz"
} |
lkml | [PATCH v3 00/47] arm_mpam: Add KVM/arm64 and resctrl glue code | This new version of the mpam missing pieces has no major rework from the
previous version. It's mainly small corrections and code tidying based on
review and things I spotted along the way. To be able to merge this we need
review from more people and people to start testing on their platforms and
giving some Tested-by ... | Hi Gavin,
On 1/19/26 12:16, Gavin Shan wrote:
Fixed
Thanks,
Ben | {
"author": "Ben Horgan <ben.horgan@arm.com>",
"date": "Mon, 19 Jan 2026 20:54:19 +0000",
"thread_id": "ca45ea06-53fa-4010-86c6-66213243b636@nvidia.com.mbox.gz"
} |
lkml | [PATCH v3 00/47] arm_mpam: Add KVM/arm64 and resctrl glue code | This new version of the mpam missing pieces has no major rework from the
previous version. It's mainly small corrections and code tidying based on
review and things I spotted along the way. To be able to merge this we need
review from more people and people to start testing on their platforms and
giving some Tested-by ... | Hi Fenghua,
On 1/15/26 23:20, Fenghua Yu wrote:
Isn't that a policy decision rather than something we should be putting
in a quirk framework?
Thanks,
Ben | {
"author": "Ben Horgan <ben.horgan@arm.com>",
"date": "Mon, 19 Jan 2026 20:56:17 +0000",
"thread_id": "ca45ea06-53fa-4010-86c6-66213243b636@nvidia.com.mbox.gz"
} |
lkml | [PATCH v3 00/47] arm_mpam: Add KVM/arm64 and resctrl glue code | This new version of the mpam missing pieces has no major rework from the
previous version. It's mainly small corrections and code tidying based on
review and things I spotted along the way. To be able to merge this we need
review from more people and people to start testing on their platforms and
giving some Tested-by ... | Hi Gavin,
On 1/19/26 12:18, Gavin Shan wrote:
Fixed
Thanks,
Ben | {
"author": "Ben Horgan <ben.horgan@arm.com>",
"date": "Mon, 19 Jan 2026 20:58:02 +0000",
"thread_id": "ca45ea06-53fa-4010-86c6-66213243b636@nvidia.com.mbox.gz"
} |
lkml | [PATCH v3 00/47] arm_mpam: Add KVM/arm64 and resctrl glue code | This new version of the mpam missing pieces has no major rework from the
previous version. It's mainly small corrections and code tidying based on
review and things I spotted along the way. To be able to merge this we need
review from more people and people to start testing on their platforms and
giving some Tested-by ... | Hi Ben and Jonathan,
On 1/19/26 10:00 PM, Ben Horgan wrote:
Yeah, I'm fine to keep it as of being :-)
Thanks,
Gavin | {
"author": "Gavin Shan <gshan@redhat.com>",
"date": "Tue, 20 Jan 2026 09:42:09 +0800",
"thread_id": "ca45ea06-53fa-4010-86c6-66213243b636@nvidia.com.mbox.gz"
} |
lkml | [PATCH v3 00/47] arm_mpam: Add KVM/arm64 and resctrl glue code | This new version of the mpam missing pieces has no major rework from the
previous version. It's mainly small corrections and code tidying based on
review and things I spotted along the way. To be able to merge this we need
review from more people and people to start testing on their platforms and
giving some Tested-by ... | Hi Ben,
On Fri, Jan 16, 2026 at 11:29 AM Ben Horgan <ben.horgan@arm.com> wrote:
We actually ended up going with the "mon_id_includes_control_id" approach.
The property it represents is rather fundamental to what a monitoring
group actually is and is a low-level implementation detail that is
difficult to hide. Google... | {
"author": "Peter Newman <peternewman@google.com>",
"date": "Tue, 20 Jan 2026 16:28:01 +0100",
"thread_id": "ca45ea06-53fa-4010-86c6-66213243b636@nvidia.com.mbox.gz"
} |
lkml | [PATCH v3 00/47] arm_mpam: Add KVM/arm64 and resctrl glue code | This new version of the mpam missing pieces has no major rework from the
previous version. It's mainly small corrections and code tidying based on
review and things I spotted along the way. To be able to merge this we need
review from more people and people to start testing on their platforms and
giving some Tested-by ... | Hi Ben and Peter,
On 1/20/26 7:28 AM, Peter Newman wrote:
Thank you for confirming. I was hoping we could deprecate num_rmids after introducing a
per resource group file but this does not seem to support all the use cases as highlighted by
Ben.
As I see it, a name like "mon_id_includes_control_id" also implies that... | {
"author": "Reinette Chatre <reinette.chatre@intel.com>",
"date": "Wed, 21 Jan 2026 09:58:45 -0800",
"thread_id": "ca45ea06-53fa-4010-86c6-66213243b636@nvidia.com.mbox.gz"
} |
lkml | [PATCH v3 00/47] arm_mpam: Add KVM/arm64 and resctrl glue code | This new version of the mpam missing pieces has no major rework from the
previous version. It's mainly small corrections and code tidying based on
review and things I spotted along the way. To be able to merge this we need
review from more people and people to start testing on their platforms and
giving some Tested-by ... | Hi Ben,
On Mon, Jan 19, 2026 at 12:23:13PM +0000, Ben Horgan wrote:
It's fine to keep it this way if LDTR/STTR are not affected by the MPAM0
register.
Since you use it for CPU suspend/resume, I guess it's fine, it saves us
from having to preserve it in the low-level asm sleep code. I don't have
a strong preference ... | {
"author": "Catalin Marinas <catalin.marinas@arm.com>",
"date": "Fri, 23 Jan 2026 14:29:42 +0000",
"thread_id": "ca45ea06-53fa-4010-86c6-66213243b636@nvidia.com.mbox.gz"
} |
lkml | [PATCH v3 00/47] arm_mpam: Add KVM/arm64 and resctrl glue code | This new version of the mpam missing pieces has no major rework from the
previous version. It's mainly small corrections and code tidying based on
review and things I spotted along the way. To be able to merge this we need
review from more people and people to start testing on their platforms and
giving some Tested-by ... | Hi Catalin,
On 1/23/26 14:29, Catalin Marinas wrote:
I see, I had misinterpreted your question.
When looking into this I spotted that the per-cpu default,
arm64_mpam_default, is not updated on the cdp enable and so the default
tasks carry on running with the non-cdp default pmg/partid configuration.
On the race its... | {
"author": "Ben Horgan <ben.horgan@arm.com>",
"date": "Mon, 26 Jan 2026 14:30:14 +0000",
"thread_id": "ca45ea06-53fa-4010-86c6-66213243b636@nvidia.com.mbox.gz"
} |
lkml | [PATCH v3 00/47] arm_mpam: Add KVM/arm64 and resctrl glue code | This new version of the mpam missing pieces has no major rework from the
previous version. It's mainly small corrections and code tidying based on
review and things I spotted along the way. To be able to merge this we need
review from more people and people to start testing on their platforms and
giving some Tested-by ... | On 1/26/26 14:30, Ben Horgan wrote:
Rather than the resume path I'll just set all the arm64_mpam_default in
resctrl_arch_set_cdp_enabled(). In code:
--- a/drivers/resctrl/mpam_resctrl.c
+++ b/drivers/resctrl/mpam_resctrl.c
@@ -193,6 +193,7 @@ static void resctrl_reset_task_closids(void)
int resctrl_arch_set_cdp_enab... | {
"author": "Ben Horgan <ben.horgan@arm.com>",
"date": "Mon, 26 Jan 2026 14:50:12 +0000",
"thread_id": "ca45ea06-53fa-4010-86c6-66213243b636@nvidia.com.mbox.gz"
} |
lkml | [PATCH v3 00/47] arm_mpam: Add KVM/arm64 and resctrl glue code | This new version of the mpam missing pieces has no major rework from the
previous version. It's mainly small corrections and code tidying based on
review and things I spotted along the way. To be able to merge this we need
review from more people and people to start testing on their platforms and
giving some Tested-by ... | Hi Peter, James,
On 1/19/26 12:47, Peter Newman wrote:
Indeed we should base our discussion on the event definition in the
Intel SDM. For our reference, the description for the external bandwidth
monitoring event (mbm_total) is:
"This event monitors the L3 total external bandwidth to the next level
of the cache hier... | {
"author": "Ben Horgan <ben.horgan@arm.com>",
"date": "Mon, 26 Jan 2026 16:00:04 +0000",
"thread_id": "ca45ea06-53fa-4010-86c6-66213243b636@nvidia.com.mbox.gz"
} |
lkml | [PATCH v3 00/47] arm_mpam: Add KVM/arm64 and resctrl glue code | This new version of the mpam missing pieces has no major rework from the
previous version. It's mainly small corrections and code tidying based on
review and things I spotted along the way. To be able to merge this we need
review from more people and people to start testing on their platforms and
giving some Tested-by ... | Hi, Ben,
On 1/19/26 12:56, Ben Horgan wrote:
MBW_MIN is 1% or 5% less than MBW_MAX.
The lower MBW_MIN hints hardware to lower mem bandwidth when mem access
contention. That causes memory performance degradation.
Is it possible to do the following changes to fix the performance issue?
1. By default min mbw is equal... | {
"author": "Fenghua Yu <fenghuay@nvidia.com>",
"date": "Thu, 29 Jan 2026 14:14:45 -0800",
"thread_id": "ca45ea06-53fa-4010-86c6-66213243b636@nvidia.com.mbox.gz"
} |
lkml | [PATCH v3 00/47] arm_mpam: Add KVM/arm64 and resctrl glue code | This new version of the mpam missing pieces has no major rework from the
previous version. It's mainly small corrections and code tidying based on
review and things I spotted along the way. To be able to merge this we need
review from more people and people to start testing on their platforms and
giving some Tested-by ... | Hi Reinette, Peter,
On 1/21/26 17:58, Reinette Chatre wrote:
I had a chat offline with James about this. Currently, userspace expects
either the copy to succeed and the counters not to glitch or the move to
fail. If we were going to support a monitor move in MPAM with counter
reset (or a best effort counter value) we... | {
"author": "Ben Horgan <ben.horgan@arm.com>",
"date": "Fri, 30 Jan 2026 11:07:31 +0000",
"thread_id": "ca45ea06-53fa-4010-86c6-66213243b636@nvidia.com.mbox.gz"
} |
lkml | [PATCH v3 00/47] arm_mpam: Add KVM/arm64 and resctrl glue code | This new version of the mpam missing pieces has no major rework from the
previous version. It's mainly small corrections and code tidying based on
review and things I spotted along the way. To be able to merge this we need
review from more people and people to start testing on their platforms and
giving some Tested-by ... | Replying to myself...
On 1/12/26 16:58, Ben Horgan wrote:
As the counter is named llc_occupancy (llc = last level cache) and we
are naming the resource L3 it would be surprising to have llc_occupancy
on anything other than an L3. Also, that L3 should be a last level
cache. I'll update this as part of a general push t... | {
"author": "Ben Horgan <ben.horgan@arm.com>",
"date": "Fri, 30 Jan 2026 11:19:29 +0000",
"thread_id": "ca45ea06-53fa-4010-86c6-66213243b636@nvidia.com.mbox.gz"
} |
lkml | [PATCH v3 00/47] arm_mpam: Add KVM/arm64 and resctrl glue code | This new version of the mpam missing pieces has no major rework from the
previous version. It's mainly small corrections and code tidying based on
review and things I spotted along the way. To be able to merge this we need
review from more people and people to start testing on their platforms and
giving some Tested-by ... | Hi Fenghua,
On 1/29/26 22:14, Fenghua Yu wrote:
Thanks for bringing this up. It raises some more general queries about
the handling of mbw_min and so I'll move the discussion to
[PATCH v3 41/47] arm_mpam: Generate a configuration for min controls
as it isn't specific to the nvidia quirks.
Thanks,
Ben | {
"author": "Ben Horgan <ben.horgan@arm.com>",
"date": "Fri, 30 Jan 2026 12:21:42 +0000",
"thread_id": "ca45ea06-53fa-4010-86c6-66213243b636@nvidia.com.mbox.gz"
} |
lkml | [PATCH v3 00/47] arm_mpam: Add KVM/arm64 and resctrl glue code | This new version of the mpam missing pieces has no major rework from the
previous version. It's mainly small corrections and code tidying based on
review and things I spotted along the way. To be able to merge this we need
review from more people and people to start testing on their platforms and
giving some Tested-by ... | Hi Ben,
On Mon, Jan 26, 2026 at 5:00 PM Ben Horgan <ben.horgan@arm.com> wrote:
The text you quoted from Intel was in the context of the L3. I assume
if such an event were implemented at a different level of the memory
system, it would continue to refer to downstream bandwidth.
That should be ok for now. If I see a ... | {
"author": "Peter Newman <peternewman@google.com>",
"date": "Fri, 30 Jan 2026 14:04:29 +0100",
"thread_id": "ca45ea06-53fa-4010-86c6-66213243b636@nvidia.com.mbox.gz"
} |
lkml | [PATCH v3 00/47] arm_mpam: Add KVM/arm64 and resctrl glue code | This new version of the mpam missing pieces has no major rework from the
previous version. It's mainly small corrections and code tidying based on
review and things I spotted along the way. To be able to merge this we need
review from more people and people to start testing on their platforms and
giving some Tested-by ... | Hi Fenghua, Jonathan,
On 1/13/26 15:39, Jonathan Cameron wrote:
I've realised it's not harmless :(
In the discussion on a platform quirk, arm_mpam: Add workaround for
T241-MPAM-4, Fenghua raised the following issues.
"
MBW_MIN is 1% or 5% less than MBW_MAX.
The lower MBW_MIN hints hardware to lower mem bandwidth... | {
"author": "Ben Horgan <ben.horgan@arm.com>",
"date": "Fri, 30 Jan 2026 14:17:38 +0000",
"thread_id": "ca45ea06-53fa-4010-86c6-66213243b636@nvidia.com.mbox.gz"
} |
lkml | [PATCH v3 00/47] arm_mpam: Add KVM/arm64 and resctrl glue code | This new version of the mpam missing pieces has no major rework from the
previous version. It's mainly small corrections and code tidying based on
review and things I spotted along the way. To be able to merge this we need
review from more people and people to start testing on their platforms and
giving some Tested-by ... | Hi Peter,
On 1/30/26 13:04, Peter Newman wrote:
Yes, that does seem reasonable. That cache level would have to match
with what is reported in resctrl too. I expect that would involve adding
a new entry in enum resctrl_scope.
Good to know. I'm looking into tightening the heuristics in general.
Please shout if any of... | {
"author": "Ben Horgan <ben.horgan@arm.com>",
"date": "Fri, 30 Jan 2026 14:38:00 +0000",
"thread_id": "ca45ea06-53fa-4010-86c6-66213243b636@nvidia.com.mbox.gz"
} |
lkml | [PATCH v3 00/47] arm_mpam: Add KVM/arm64 and resctrl glue code | This new version of the mpam missing pieces has no major rework from the
previous version. It's mainly small corrections and code tidying based on
review and things I spotted along the way. To be able to merge this we need
review from more people and people to start testing on their platforms and
giving some Tested-by ... | Hi Ben,
On 1/30/2026 8:17 AM, Ben Horgan wrote:
Background: I previouslyshared original fix(seecodesnippet below) with
James Morse
~2 years ago to address the errata, which explicitly recommends usinga
5% gap for
mitigation of the Hardware issue (the problem described in commit text
of T241-MPAM-4)
For some reaso... | {
"author": "Shanker Donthineni <sdonthineni@nvidia.com>",
"date": "Fri, 30 Jan 2026 20:30:01 -0600",
"thread_id": "ca45ea06-53fa-4010-86c6-66213243b636@nvidia.com.mbox.gz"
} |
lkml | [PATCH v3 00/47] arm_mpam: Add KVM/arm64 and resctrl glue code | This new version of the mpam missing pieces has no major rework from the
previous version. It's mainly small corrections and code tidying based on
review and things I spotted along the way. To be able to merge this we need
review from more people and people to start testing on their platforms and
giving some Tested-by ... | Hi Shanker,
On 1/31/26 02:30, Shanker Donthineni wrote:
What's the behaviour on T241 when MBW_MIN is always 0xFFFF?
I'm worried if we make a policy decision of how to set MBW_MIN based on
MBW_MAX for this platform then we won't be able to support a
configurable MBW_MIN in the future for this platform. As when MBW_M... | {
"author": "Ben Horgan <ben.horgan@arm.com>",
"date": "Mon, 2 Feb 2026 10:21:28 +0000",
"thread_id": "ca45ea06-53fa-4010-86c6-66213243b636@nvidia.com.mbox.gz"
} |
lkml | [PATCH v3 00/47] arm_mpam: Add KVM/arm64 and resctrl glue code | This new version of the mpam missing pieces has no major rework from the
previous version. It's mainly small corrections and code tidying based on
review and things I spotted along the way. To be able to merge this we need
review from more people and people to start testing on their platforms and
giving some Tested-by ... | Hi Ben,
On 2/2/2026 4:21 AM, Ben Horgan wrote:
Memory bandwidth throttling will not function correctly. The MPAM hardware
monitors MIN and MAX values for each active partition to maintain memory
bandwidth usage between MBW_MIN and MBW_MAX. Therefore, MBW_MIN must be
less than MBW_MAX (IMO, setting MBW_MIN to always 0... | {
"author": "Shanker Donthineni <sdonthineni@nvidia.com>",
"date": "Mon, 2 Feb 2026 10:34:18 -0600",
"thread_id": "ca45ea06-53fa-4010-86c6-66213243b636@nvidia.com.mbox.gz"
} |
lkml | [syzbot] [kvm?] WARNING in kvm_gmem_fault_user_mapping | Hello,
syzbot found the following issue on:
HEAD commit: 1f97d9dcf536 Merge tag 'vfio-v6.19-rc8' of https://github...
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=10b3e322580000
kernel config: https://syzkaller.appspot.com/x/.config?x=f1fac0919970b671
dashboard link: https://... | Hello,
syzbot has tested the proposed patch but the reproducer is still triggering an issue:
WARNING in kvm_gmem_fault_user_mapping
------------[ cut here ]------------
folio_test_large(folio)
WARNING: arch/x86/kvm/../../../virt/kvm/guest_memfd.c:416 at kvm_gmem_fault_user_mapping+0x4b5/0x6e0 virt/kvm/guest_memfd.c:4... | {
"author": "syzbot <syzbot+33a04338019ac7e43a44@syzkaller.appspotmail.com>",
"date": "Sat, 31 Jan 2026 21:40:03 -0800",
"thread_id": "6980d327.050a0220.1d0a41.002a.GAE@google.com.mbox.gz"
} |
lkml | [syzbot] [kvm?] WARNING in kvm_gmem_fault_user_mapping | Hello,
syzbot found the following issue on:
HEAD commit: 1f97d9dcf536 Merge tag 'vfio-v6.19-rc8' of https://github...
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=10b3e322580000
kernel config: https://syzkaller.appspot.com/x/.config?x=f1fac0919970b671
dashboard link: https://... | Hello,
syzbot has tested the proposed patch and the reproducer did not trigger any issue:
Reported-by: syzbot+33a04338019ac7e43a44@syzkaller.appspotmail.com
Tested-by: syzbot+33a04338019ac7e43a44@syzkaller.appspotmail.com
Tested on:
commit: 162b4244 Merge tag 'iommu-fixes-v6.19-rc7' of git://gi..
git tree: ... | {
"author": "syzbot <syzbot+33a04338019ac7e43a44@syzkaller.appspotmail.com>",
"date": "Sat, 31 Jan 2026 22:25:03 -0800",
"thread_id": "6980d327.050a0220.1d0a41.002a.GAE@google.com.mbox.gz"
} |
lkml | [syzbot] [kvm?] WARNING in kvm_gmem_fault_user_mapping | Hello,
syzbot found the following issue on:
HEAD commit: 1f97d9dcf536 Merge tag 'vfio-v6.19-rc8' of https://github...
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=10b3e322580000
kernel config: https://syzkaller.appspot.com/x/.config?x=f1fac0919970b671
dashboard link: https://... | Hello,
syzbot has tested the proposed patch but the reproducer is still triggering an issue:
WARNING in kvm_gmem_create
------------[ cut here ]------------
!mapping_unevictable(inode->i_mapping)
WARNING: arch/x86/kvm/../../../virt/kvm/guest_memfd.c:601 at __kvm_gmem_create virt/kvm/guest_memfd.c:601 [inline], CPU#0:... | {
"author": "syzbot <syzbot+33a04338019ac7e43a44@syzkaller.appspotmail.com>",
"date": "Sun, 01 Feb 2026 02:33:03 -0800",
"thread_id": "6980d327.050a0220.1d0a41.002a.GAE@google.com.mbox.gz"
} |
lkml | [syzbot] [kvm?] WARNING in kvm_gmem_fault_user_mapping | Hello,
syzbot found the following issue on:
HEAD commit: 1f97d9dcf536 Merge tag 'vfio-v6.19-rc8' of https://github...
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=10b3e322580000
kernel config: https://syzkaller.appspot.com/x/.config?x=f1fac0919970b671
dashboard link: https://... | Hello,
syzbot has tested the proposed patch but the reproducer is still triggering an issue:
WARNING in kvm_gmem_fault_user_mapping
------------[ cut here ]------------
folio_test_large(folio)
WARNING: arch/x86/kvm/../../../virt/kvm/guest_memfd.c:416 at kvm_gmem_fault_user_mapping+0x4b5/0x6e0 virt/kvm/guest_memfd.c:4... | {
"author": "syzbot <syzbot+33a04338019ac7e43a44@syzkaller.appspotmail.com>",
"date": "Sun, 01 Feb 2026 03:39:04 -0800",
"thread_id": "6980d327.050a0220.1d0a41.002a.GAE@google.com.mbox.gz"
} |
lkml | [syzbot] [kvm?] WARNING in kvm_gmem_fault_user_mapping | Hello,
syzbot found the following issue on:
HEAD commit: 1f97d9dcf536 Merge tag 'vfio-v6.19-rc8' of https://github...
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=10b3e322580000
kernel config: https://syzkaller.appspot.com/x/.config?x=f1fac0919970b671
dashboard link: https://... | Hello,
syzbot has tested the proposed patch but the reproducer is still triggering an issue:
kernel BUG in filemap_remove_folio
------------[ cut here ]------------
kernel BUG at mm/filemap.c:254!
Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI
CPU: 1 UID: 0 PID: 7475 Comm: syz.2.329 Not tainted syzkaller #0 PREEMPT(... | {
"author": "syzbot <syzbot+33a04338019ac7e43a44@syzkaller.appspotmail.com>",
"date": "Mon, 02 Feb 2026 02:52:01 -0800",
"thread_id": "6980d327.050a0220.1d0a41.002a.GAE@google.com.mbox.gz"
} |
lkml | [syzbot] [kvm?] WARNING in kvm_gmem_fault_user_mapping | Hello,
syzbot found the following issue on:
HEAD commit: 1f97d9dcf536 Merge tag 'vfio-v6.19-rc8' of https://github...
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=10b3e322580000
kernel config: https://syzkaller.appspot.com/x/.config?x=f1fac0919970b671
dashboard link: https://... | Hello,
syzbot has tested the proposed patch and the reproducer did not trigger any issue:
Reported-by: syzbot+33a04338019ac7e43a44@syzkaller.appspotmail.com
Tested-by: syzbot+33a04338019ac7e43a44@syzkaller.appspotmail.com
Tested on:
commit: 18f7fcd5 Linux 6.19-rc8
git tree: upstream
console output: ht... | {
"author": "syzbot <syzbot+33a04338019ac7e43a44@syzkaller.appspotmail.com>",
"date": "Mon, 02 Feb 2026 08:39:03 -0800",
"thread_id": "6980d327.050a0220.1d0a41.002a.GAE@google.com.mbox.gz"
} |
lkml | [PATCHSET v3 sched_ext/for-6.20] sched_ext: Fix ops.dequeue() semantics | The callback ops.dequeue() is provided to let BPF schedulers observe when a
task leaves the scheduler, either because it is dispatched or due to a task
property change. However, this callback is currently unreliable and not
invoked systematically, which can result in missed ops.dequeue() events.
In particular, once a ... | Currently, ops.dequeue() is only invoked when the sched_ext core knows
that a task resides in BPF-managed data structures, which causes it to
miss scheduling property change scenarios. As a result, BPF schedulers
cannot reliably track task state.
In addition, some ops.dequeue() callbacks can be skipped (e.g., during
d... | {
"author": "Andrea Righi <arighi@nvidia.com>",
"date": "Mon, 26 Jan 2026 09:41:49 +0100",
"thread_id": "20260126084258.3798129-1-arighi@nvidia.com.mbox.gz"
} |
lkml | [PATCHSET v3 sched_ext/for-6.20] sched_ext: Fix ops.dequeue() semantics | The callback ops.dequeue() is provided to let BPF schedulers observe when a
task leaves the scheduler, either because it is dispatched or due to a task
property change. However, this callback is currently unreliable and not
invoked systematically, which can result in missed ops.dequeue() events.
In particular, once a ... | Add a new kselftest to validate that:
- every enqueue is followed by proper dequeue,
- dispatch dequeues happen exactly once per enqueue,
- property change dequeues (%SCX_DEQ_SCHED_CHANGE) only happen for
property changes,
- no duplicate enqueues without proper dequeue.
Test scenarios:
- direct dispatch to loc... | {
"author": "Andrea Righi <arighi@nvidia.com>",
"date": "Mon, 26 Jan 2026 09:41:50 +0100",
"thread_id": "20260126084258.3798129-1-arighi@nvidia.com.mbox.gz"
} |
lkml | [PATCHSET v3 sched_ext/for-6.20] sched_ext: Fix ops.dequeue() semantics | The callback ops.dequeue() is provided to let BPF schedulers observe when a
task leaves the scheduler, either because it is dispatched or due to a task
property change. However, this callback is currently unreliable and not
invoked systematically, which can result in missed ops.dequeue() events.
In particular, once a ... | On Mon Jan 26, 2026 at 3:41 AM EST, Andrea Righi wrote:
Reviewed-by: Emil Tsalapatis <emil@etsalapatis.com>
Looks great overall. Following up on our off-list chat about whether
SCX_TASK_DISPATCH_DEQUEUED is necessary: We need it for the new DEQ_STATE
change flag so no need to consider removing it imo. | {
"author": "\"Emil Tsalapatis\" <emil@etsalapatis.com>",
"date": "Tue, 27 Jan 2026 11:38:45 -0500",
"thread_id": "20260126084258.3798129-1-arighi@nvidia.com.mbox.gz"
} |
lkml | [PATCHSET v3 sched_ext/for-6.20] sched_ext: Fix ops.dequeue() semantics | The callback ops.dequeue() is provided to let BPF schedulers observe when a
task leaves the scheduler, either because it is dispatched or due to a task
property change. However, this callback is currently unreliable and not
invoked systematically, which can result in missed ops.dequeue() events.
In particular, once a ... | Hi Andrea,
On Mon Jan 26, 2026 at 8:41 AM UTC, Andrea Righi wrote:
Not sure I follow this paragraph, specifically the first sentence
(starting with ``ops.dequeue()`` is called ...).
It seems to imply that a task that has already been dispatched to a DSQ still
counts as enqueued, but the preceding text contradicts tha... | {
"author": "Kuba Piecuch <jpiecuch@google.com>",
"date": "Tue, 27 Jan 2026 16:41:43 +0000",
"thread_id": "20260126084258.3798129-1-arighi@nvidia.com.mbox.gz"
} |
lkml | [PATCHSET v3 sched_ext/for-6.20] sched_ext: Fix ops.dequeue() semantics | The callback ops.dequeue() is provided to let BPF schedulers observe when a
task leaves the scheduler, either because it is dispatched or due to a task
property change. However, this callback is currently unreliable and not
invoked systematically, which can result in missed ops.dequeue() events.
In particular, once a ... | On Mon Jan 26, 2026 at 3:41 AM EST, Andrea Righi wrote:
Reviewed-by: Emil Tsalapatis <emil@etsalapatis.com> | {
"author": "\"Emil Tsalapatis\" <emil@etsalapatis.com>",
"date": "Tue, 27 Jan 2026 11:53:57 -0500",
"thread_id": "20260126084258.3798129-1-arighi@nvidia.com.mbox.gz"
} |
lkml | [PATCHSET v3 sched_ext/for-6.20] sched_ext: Fix ops.dequeue() semantics | The callback ops.dequeue() is provided to let BPF schedulers observe when a
task leaves the scheduler, either because it is dispatched or due to a task
property change. However, this callback is currently unreliable and not
invoked systematically, which can result in missed ops.dequeue() events.
In particular, once a ... | Hello,
On Mon, Jan 26, 2026 at 09:41:49AM +0100, Andrea Righi wrote:
1. When to call ops.dequeue()?
I'm not sure whether deciding whether to call ops.dequeue() solely onwhether
ops.enqueue() was called. Direct dispatch has been expanded to include other
DSQs but was originally added as a way to shortcut the dispatch... | {
"author": "Tejun Heo <tj@kernel.org>",
"date": "Wed, 28 Jan 2026 11:21:09 -1000",
"thread_id": "20260126084258.3798129-1-arighi@nvidia.com.mbox.gz"
} |
lkml | [PATCHSET v3 sched_ext/for-6.20] sched_ext: Fix ops.dequeue() semantics | The callback ops.dequeue() is provided to let BPF schedulers observe when a
task leaves the scheduler, either because it is dispatched or due to a task
property change. However, this callback is currently unreliable and not
invoked systematically, which can result in missed ops.dequeue() events.
In particular, once a ... | Hi Kuba,
On Tue, Jan 27, 2026 at 04:41:43PM +0000, Kuba Piecuch wrote:
...
Good point, the confusion is on my side, the documentation overloads the
term "enqueued" and doesn't clearly distinguish the different contexts.
In that paragraph, "enqueued" refers to the ops lifecycle (i.e., a task for
which ops.enqueue() h... | {
"author": "Andrea Righi <arighi@nvidia.com>",
"date": "Fri, 30 Jan 2026 08:34:30 +0100",
"thread_id": "20260126084258.3798129-1-arighi@nvidia.com.mbox.gz"
} |
lkml | [PATCHSET v3 sched_ext/for-6.20] sched_ext: Fix ops.dequeue() semantics | The callback ops.dequeue() is provided to let BPF schedulers observe when a
task leaves the scheduler, either because it is dispatched or due to a task
property change. However, this callback is currently unreliable and not
invoked systematically, which can result in missed ops.dequeue() events.
In particular, once a ... | Hi Tejun,
On Wed Jan 28, 2026 at 9:21 PM UTC, Tejun Heo wrote:
...
Is "local" short for "local or global", i.e. not user-created?
Direct dispatching into the global DSQ also shouldn't trigger ops.dequeue(),
since dispatch isn't necessary for the task to run. This follows from the last
paragraph:
Note that, this wa... | {
"author": "Kuba Piecuch <jpiecuch@google.com>",
"date": "Fri, 30 Jan 2026 11:54:00 +0000",
"thread_id": "20260126084258.3798129-1-arighi@nvidia.com.mbox.gz"
} |
lkml | [PATCHSET v3 sched_ext/for-6.20] sched_ext: Fix ops.dequeue() semantics | The callback ops.dequeue() is provided to let BPF schedulers observe when a
task leaves the scheduler, either because it is dispatched or due to a task
property change. However, this callback is currently unreliable and not
invoked systematically, which can result in missed ops.dequeue() events.
In particular, once a ... | Hi Andrea,
On Fri Jan 30, 2026 at 7:34 AM UTC, Andrea Righi wrote:
...
Right, skipping ops.dequeue() for direct dispatches makes sense, provided
the task is being dispatched to a local/global DSQ. Or at least that's my
takeaway after reading Tejun's email.
...
Ok, I think I understand the logic behind this, here's ... | {
"author": "Kuba Piecuch <jpiecuch@google.com>",
"date": "Fri, 30 Jan 2026 13:14:23 +0000",
"thread_id": "20260126084258.3798129-1-arighi@nvidia.com.mbox.gz"
} |
lkml | [PATCHSET v3 sched_ext/for-6.20] sched_ext: Fix ops.dequeue() semantics | The callback ops.dequeue() is provided to let BPF schedulers observe when a
task leaves the scheduler, either because it is dispatched or due to a task
property change. However, this callback is currently unreliable and not
invoked systematically, which can result in missed ops.dequeue() events.
In particular, once a ... | Hi Kuba,
On Fri, Jan 30, 2026 at 01:14:23PM +0000, Kuba Piecuch wrote:
...
Correct. And it's also a way to notify that the task has left the BPF
scheduler, so if the task is stored in any internal queue it can/should be
removed.
Actually I think the proper behavior would be to trigger
ops.dequeue(SCHED_CHANGE) only... | {
"author": "Andrea Righi <arighi@nvidia.com>",
"date": "Sat, 31 Jan 2026 07:54:13 +0100",
"thread_id": "20260126084258.3798129-1-arighi@nvidia.com.mbox.gz"
} |
lkml | [PATCHSET v3 sched_ext/for-6.20] sched_ext: Fix ops.dequeue() semantics | The callback ops.dequeue() is provided to let BPF schedulers observe when a
task leaves the scheduler, either because it is dispatched or due to a task
property change. However, this callback is currently unreliable and not
invoked systematically, which can result in missed ops.dequeue() events.
In particular, once a ... | On Fri, Jan 30, 2026 at 11:54:00AM +0000, Kuba Piecuch wrote:
I think this should be interpreted as local DSQs only
(SCX_DSQ_LOCAL / SCX_DSQ_LOCAL_ON), not any built-in DSQ. SCX_DSQ_GLOBAL is
essentially a built-in user DSQ, provided for convenience, it's not really
a "direct dispatch" DSQ.
This looks good overall, ... | {
"author": "Andrea Righi <arighi@nvidia.com>",
"date": "Sat, 31 Jan 2026 10:02:19 +0100",
"thread_id": "20260126084258.3798129-1-arighi@nvidia.com.mbox.gz"
} |
lkml | [PATCHSET v3 sched_ext/for-6.20] sched_ext: Fix ops.dequeue() semantics | The callback ops.dequeue() is provided to let BPF schedulers observe when a
task leaves the scheduler, either because it is dispatched or due to a task
property change. However, this callback is currently unreliable and not
invoked systematically, which can result in missed ops.dequeue() events.
In particular, once a ... | Hi Andrea,
On Sat Jan 31, 2026 at 6:54 AM UTC, Andrea Righi wrote:
Right, unless the task has already been dispatched, in which case it's just
an invalidation notification.
I don't think this is what the current implementation does, right?
That would make sense if ops.enqueue() was called immediately after a prop... | {
"author": "Kuba Piecuch <jpiecuch@google.com>",
"date": "Sat, 31 Jan 2026 16:45:59 +0000",
"thread_id": "20260126084258.3798129-1-arighi@nvidia.com.mbox.gz"
} |
lkml | [PATCHSET v3 sched_ext/for-6.20] sched_ext: Fix ops.dequeue() semantics | The callback ops.dequeue() is provided to let BPF schedulers observe when a
task leaves the scheduler, either because it is dispatched or due to a task
property change. However, this callback is currently unreliable and not
invoked systematically, which can result in missed ops.dequeue() events.
In particular, once a ... | Hi Kuba,
On Sat, Jan 31, 2026 at 04:45:59PM +0000, Kuba Piecuch wrote:
...
Right, but if the task has already been dispatched I don't think we should
trigger ops.dequeue(SCHED_CHANGE), because it's not anymore under the BPF
scheduler's custody (not the way it's implemented right now, I'm just
trying to define the pro... | {
"author": "Andrea Righi <arighi@nvidia.com>",
"date": "Sat, 31 Jan 2026 18:24:06 +0100",
"thread_id": "20260126084258.3798129-1-arighi@nvidia.com.mbox.gz"
} |
lkml | [PATCHSET v3 sched_ext/for-6.20] sched_ext: Fix ops.dequeue() semantics | The callback ops.dequeue() is provided to let BPF schedulers observe when a
task leaves the scheduler, either because it is dispatched or due to a task
property change. However, this callback is currently unreliable and not
invoked systematically, which can result in missed ops.dequeue() events.
In particular, once a ... | On Sat Jan 31, 2026 at 9:02 AM UTC, Andrea Righi wrote:
SCX_DSQ_GLOBAL is significantly different from user DSQs, because balance_one()
can pull tasks directly from SCX_DSQ_GLOBAL, while it cannot pull tasks from
user-created DSQs.
If a BPF scheduler puts a task onto SCX_DSQ_GLOBAL, then it _must_ be ok with
balance_... | {
"author": "Kuba Piecuch <jpiecuch@google.com>",
"date": "Sat, 31 Jan 2026 17:53:27 +0000",
"thread_id": "20260126084258.3798129-1-arighi@nvidia.com.mbox.gz"
} |
lkml | [PATCHSET v3 sched_ext/for-6.20] sched_ext: Fix ops.dequeue() semantics | The callback ops.dequeue() is provided to let BPF schedulers observe when a
task leaves the scheduler, either because it is dispatched or due to a task
property change. However, this callback is currently unreliable and not
invoked systematically, which can result in missed ops.dequeue() events.
In particular, once a ... | On Sat, Jan 31, 2026 at 05:53:27PM +0000, Kuba Piecuch wrote:
I agree that SCX_DSQ_GLOBAL behaves differently from user-created DSQs at
the implementation level, but I think that difference shouldn't leak into
the logical model.
not mean that the task leaves the "enqueued by BPF" state. The task is
still under the BP... | {
"author": "Andrea Righi <arighi@nvidia.com>",
"date": "Sat, 31 Jan 2026 21:26:56 +0100",
"thread_id": "20260126084258.3798129-1-arighi@nvidia.com.mbox.gz"
} |
lkml | [PATCHSET v3 sched_ext/for-6.20] sched_ext: Fix ops.dequeue() semantics | The callback ops.dequeue() is provided to let BPF schedulers observe when a
task leaves the scheduler, either because it is dispatched or due to a task
property change. However, this callback is currently unreliable and not
invoked systematically, which can result in missed ops.dequeue() events.
In particular, once a ... | Hello,
Sorry about tardiness.
On Fri, Jan 30, 2026 at 11:54:00AM +0000, Kuba Piecuch wrote:
Yes, maybe it'd be useful to come up with a terminology for them. e.g.
terminal - once a task reaches a terminal DSQ, the only way that the BPF
scheduler can affect the task is by triggering re-enqueue (although we don't
yet ... | {
"author": "Tejun Heo <tj@kernel.org>",
"date": "Sun, 1 Feb 2026 07:43:33 -1000",
"thread_id": "20260126084258.3798129-1-arighi@nvidia.com.mbox.gz"
} |
lkml | [PATCHSET v3 sched_ext/for-6.20] sched_ext: Fix ops.dequeue() semantics | The callback ops.dequeue() is provided to let BPF schedulers observe when a
task leaves the scheduler, either because it is dispatched or due to a task
property change. However, this callback is currently unreliable and not
invoked systematically, which can result in missed ops.dequeue() events.
In particular, once a ... | Hello,
On Sat, Jan 31, 2026 at 09:26:56PM +0100, Andrea Righi wrote:
I think putting a task into GLOBAL means that the BPF scheduler is done with
it. Another data point in this direction is that when insertion into a local
DSQ can't be done, the task falls back to the global DSQ although all the
current ones also tri... | {
"author": "Tejun Heo <tj@kernel.org>",
"date": "Mon, 2 Feb 2026 05:19:51 -1000",
"thread_id": "20260126084258.3798129-1-arighi@nvidia.com.mbox.gz"
} |
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