The patch below does not apply to the 6.12-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.12.y git checkout FETCH_HEAD git cherry-pick -x c4af66a95aa3bc1d4f607ebd4eea524fb58946e3 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to 'stable@vger.kernel.org' --in-reply-to '2025040113-pellet-sanding-f62c@gregkh' --subject-prefix 'PATCH 6.12.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From c4af66a95aa3bc1d4f607ebd4eea524fb58946e3 Mon Sep 17 00:00:00 2001 From: Abel Wu wuyun.abel@bytedance.com Date: Sun, 9 Feb 2025 14:13:11 +0800 Subject: [PATCH] cgroup/rstat: Fix forceidle time in cpu.stat
The commit b824766504e4 ("cgroup/rstat: add force idle show helper") retrieves forceidle_time outside cgroup_rstat_lock for non-root cgroups which can be potentially inconsistent with other stats.
Rather than reverting that commit, fix it in a way that retains the effort of cleaning up the ifdef-messes.
Fixes: b824766504e4 ("cgroup/rstat: add force idle show helper") Signed-off-by: Abel Wu wuyun.abel@bytedance.com Signed-off-by: Tejun Heo tj@kernel.org
diff --git a/kernel/cgroup/rstat.c b/kernel/cgroup/rstat.c index 5877974ece92..c2784c317cdd 100644 --- a/kernel/cgroup/rstat.c +++ b/kernel/cgroup/rstat.c @@ -613,36 +613,33 @@ static void cgroup_force_idle_show(struct seq_file *seq, struct cgroup_base_stat void cgroup_base_stat_cputime_show(struct seq_file *seq) { struct cgroup *cgrp = seq_css(seq)->cgroup; - u64 usage, utime, stime, ntime; + struct cgroup_base_stat bstat;
if (cgroup_parent(cgrp)) { cgroup_rstat_flush_hold(cgrp); - usage = cgrp->bstat.cputime.sum_exec_runtime; + bstat = cgrp->bstat; cputime_adjust(&cgrp->bstat.cputime, &cgrp->prev_cputime, - &utime, &stime); - ntime = cgrp->bstat.ntime; + &bstat.cputime.utime, &bstat.cputime.stime); cgroup_rstat_flush_release(cgrp); } else { - /* cgrp->bstat of root is not actually used, reuse it */ - root_cgroup_cputime(&cgrp->bstat); - usage = cgrp->bstat.cputime.sum_exec_runtime; - utime = cgrp->bstat.cputime.utime; - stime = cgrp->bstat.cputime.stime; - ntime = cgrp->bstat.ntime; + root_cgroup_cputime(&bstat); }
- do_div(usage, NSEC_PER_USEC); - do_div(utime, NSEC_PER_USEC); - do_div(stime, NSEC_PER_USEC); - do_div(ntime, NSEC_PER_USEC); + do_div(bstat.cputime.sum_exec_runtime, NSEC_PER_USEC); + do_div(bstat.cputime.utime, NSEC_PER_USEC); + do_div(bstat.cputime.stime, NSEC_PER_USEC); + do_div(bstat.ntime, NSEC_PER_USEC);
seq_printf(seq, "usage_usec %llu\n" "user_usec %llu\n" "system_usec %llu\n" "nice_usec %llu\n", - usage, utime, stime, ntime); + bstat.cputime.sum_exec_runtime, + bstat.cputime.utime, + bstat.cputime.stime, + bstat.ntime);
- cgroup_force_idle_show(seq, &cgrp->bstat); + cgroup_force_idle_show(seq, &bstat); }
/* Add bpf kfuncs for cgroup_rstat_updated() and cgroup_rstat_flush() */