[Devel] [PATCH hci-8.1 v2 0/2] sched: Fix incorrect nproc report inside CT

[Pavel Tikhomirov]

Looks good. (except that sashiko reveiw should be handled)

Reviewed-by: Pavel Tikhomirov <ptikhomirov at virtuozzo.com>

On 10/28/26 13:46, Vladimir Riabchun wrote:
> We observed weird nproc behavior - it reported 64 CPUs
> no matter what the CT limits were or how many CPUs the host
> actually had.
> 
> nproc code uses sched_getaffinity syscall under the hood[1].
> It appears that this syscall returned complete nonsence when
> called from VE - we ignored both num_online_vcpus and
> cgroup cpuset limitations.
> 
> Now it is fixed and a new selftest is added.
> 
> [1]: https://github.com/coreutils/gnulib/blob/master/lib/nproc.c#L144
> https://virtuozzo.atlassian.net/browse/VSTOR-141682
> 
> Signed-off-by: Vladimir Riabchun <vladimir.riabchun at virtuozzo.com>
> ---
> Changes in v2:
> - Updated vCPU logic in patch 1. Now we don't return actual
>   cpumask, insted first min(vcpu, count(mask)) bits are set.
>   This is closer to the real CT resources.
> - Patch 2: adjusted logic and added one more test.
> - Link to v1: http://lore.virtuozzo.com/20261027-ct-invalid-nrpoc-v1-0-48727c3afe16@virtuozzo.com
> 
> ---
> Vladimir Riabchun (2):
>       sched: Fix sched_getaffinity syscall
>       selftests: ve: Test sched_getaffinity in VE
> 
>  kernel/sched/syscalls.c                            |  18 +-
>  tools/testing/selftests/ve/.gitignore              |   1 +
>  tools/testing/selftests/ve/Makefile                |   1 +
>  .../selftests/ve/ve_sched_getaffinity_test.c       | 213 +++++++++++++++++++++
>  4 files changed, 228 insertions(+), 5 deletions(-)
> ---
> base-commit: a1c0fd720976500f854fd5a4c946a54e65c82d78
> change-id: 20261027-ct-invalid-nrpoc-f183b3ba691d
> 
> Best regards,
> --  
> Vladimir Riabchun <vladimir.riabchun at virtuozzo.com>

-- 
Best regards, Pavel Tikhomirov
Senior Software Developer, Virtuozzo.