Commit c4af66a9 authored by Abel Wu's avatar Abel Wu Committed by Tejun Heo
Browse files

cgroup/rstat: Fix forceidle time in cpu.stat 



The commit b8247665 ("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: b8247665 ("cgroup/rstat: add force idle show helper")
Signed-off-by: default avatarAbel Wu <wuyun.abel@bytedance.com>
Signed-off-by: default avatarTejun Heo <tj@kernel.org>
parent ad6c08d8

kernel/cgroup/rstat.c

+13 −16
Original line number Diff line number Diff line
@@ -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() */