6.12-stable review patch. If anyone has any objections, please let me know.
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From: Joshua Hahn joshua.hahn6@gmail.com
[ Upstream commit aefa398d93d5db7c555be78a605ff015357f127d ]
Cgroup-level CPU statistics currently include time spent on user/system processes, but do not include niced CPU time (despite already being tracked). This patch exposes niced CPU time to the userspace, allowing users to get a better understanding of their hardware limits and can facilitate more informed workload distribution.
A new field 'ntime' is added to struct cgroup_base_stat as opposed to struct task_cputime to minimize footprint.
Signed-off-by: Joshua Hahn joshua.hahnjy@gmail.com Signed-off-by: Tejun Heo tj@kernel.org Stable-dep-of: c4af66a95aa3 ("cgroup/rstat: Fix forceidle time in cpu.stat") Signed-off-by: Sasha Levin sashal@kernel.org --- include/linux/cgroup-defs.h | 1 + kernel/cgroup/rstat.c | 19 ++++++++++++++----- 2 files changed, 15 insertions(+), 5 deletions(-)
diff --git a/include/linux/cgroup-defs.h b/include/linux/cgroup-defs.h index a32eebcd23da4..38b2af336e4a0 100644 --- a/include/linux/cgroup-defs.h +++ b/include/linux/cgroup-defs.h @@ -324,6 +324,7 @@ struct cgroup_base_stat { #ifdef CONFIG_SCHED_CORE u64 forceidle_sum; #endif + u64 ntime; };
/* diff --git a/kernel/cgroup/rstat.c b/kernel/cgroup/rstat.c index ce295b73c0a36..aac91466279f1 100644 --- a/kernel/cgroup/rstat.c +++ b/kernel/cgroup/rstat.c @@ -444,6 +444,7 @@ static void cgroup_base_stat_add(struct cgroup_base_stat *dst_bstat, #ifdef CONFIG_SCHED_CORE dst_bstat->forceidle_sum += src_bstat->forceidle_sum; #endif + dst_bstat->ntime += src_bstat->ntime; }
static void cgroup_base_stat_sub(struct cgroup_base_stat *dst_bstat, @@ -455,6 +456,7 @@ static void cgroup_base_stat_sub(struct cgroup_base_stat *dst_bstat, #ifdef CONFIG_SCHED_CORE dst_bstat->forceidle_sum -= src_bstat->forceidle_sum; #endif + dst_bstat->ntime -= src_bstat->ntime; }
static void cgroup_base_stat_flush(struct cgroup *cgrp, int cpu) @@ -534,8 +536,10 @@ void __cgroup_account_cputime_field(struct cgroup *cgrp, rstatc = cgroup_base_stat_cputime_account_begin(cgrp, &flags);
switch (index) { - case CPUTIME_USER: case CPUTIME_NICE: + rstatc->bstat.ntime += delta_exec; + fallthrough; + case CPUTIME_USER: rstatc->bstat.cputime.utime += delta_exec; break; case CPUTIME_SYSTEM: @@ -590,6 +594,7 @@ static void root_cgroup_cputime(struct cgroup_base_stat *bstat) #ifdef CONFIG_SCHED_CORE bstat->forceidle_sum += cpustat[CPUTIME_FORCEIDLE]; #endif + bstat->ntime += cpustat[CPUTIME_NICE]; } }
@@ -607,13 +612,14 @@ 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; + u64 usage, utime, stime, ntime;
if (cgroup_parent(cgrp)) { cgroup_rstat_flush_hold(cgrp); usage = cgrp->bstat.cputime.sum_exec_runtime; cputime_adjust(&cgrp->bstat.cputime, &cgrp->prev_cputime, &utime, &stime); + ntime = cgrp->bstat.ntime; cgroup_rstat_flush_release(cgrp); } else { /* cgrp->bstat of root is not actually used, reuse it */ @@ -621,16 +627,19 @@ void cgroup_base_stat_cputime_show(struct seq_file *seq) usage = cgrp->bstat.cputime.sum_exec_runtime; utime = cgrp->bstat.cputime.utime; stime = cgrp->bstat.cputime.stime; + ntime = cgrp->bstat.ntime; }
do_div(usage, NSEC_PER_USEC); do_div(utime, NSEC_PER_USEC); do_div(stime, NSEC_PER_USEC); + do_div(ntime, NSEC_PER_USEC);
seq_printf(seq, "usage_usec %llu\n" - "user_usec %llu\n" - "system_usec %llu\n", - usage, utime, stime); + "user_usec %llu\n" + "system_usec %llu\n" + "nice_usec %llu\n", + usage, utime, stime, ntime);
cgroup_force_idle_show(seq, &cgrp->bstat); }