From: Vladimir Riabchun <vladimir.riabchun@virtuozzo.com>
To: ptikhomirov@virtuozzo.com, Konstantin Khorenko <khorenko@virtuozzo.com>
Cc: devel@openvz.org
Subject: [Devel] [PATCH hci-8.1 0/2] sched: Fix incorrect nproc report inside CT
Date: Tue, 27 Oct 2026 21:51:09 +0100 [thread overview]
Message-ID: <20261027-ct-invalid-nrpoc-v1-0-48727c3afe16@virtuozzo.com> (raw)
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@virtuozzo.com>
---
Vladimir Riabchun (2):
sched: Fix sched_getaffinity syscall
selftests: ve: Test sched_getaffinity in VE
kernel/sched/syscalls.c | 13 +-
tools/testing/selftests/ve/.gitignore | 1 +
tools/testing/selftests/ve/Makefile | 1 +
.../selftests/ve/ve_sched_getaffinity_test.c | 147 +++++++++++++++++++++
4 files changed, 156 insertions(+), 6 deletions(-)
---
base-commit: a1c0fd720976500f854fd5a4c946a54e65c82d78
change-id: 20261027-ct-invalid-nrpoc-f183b3ba691d
Best regards,
--
Vladimir Riabchun <vladimir.riabchun@virtuozzo.com>
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next reply other threads:[~2026-10-27 20:53 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-10-27 20:51 Vladimir Riabchun [this message]
2026-10-27 20:51 ` [Devel] [PATCH hci-8.1 1/2] sched: Fix sched_getaffinity syscall Vladimir Riabchun
2026-10-28 9:34 ` Pavel Tikhomirov
2026-10-28 10:30 ` Vladimir Riabchun
2026-10-27 20:51 ` [Devel] [PATCH hci-8.1 2/2] selftests: ve: Test sched_getaffinity in VE Vladimir Riabchun
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