From: Joshua Hahn joshua.hahn6@gmail.com
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 better load-balancing.
A new field 'ntime' is added to struct cgroup_base_stat as opposed to struct task_cputime to minimize footprint. --- include/linux/cgroup-defs.h | 1 + kernel/cgroup/rstat.c | 16 +++++++++++++--- 2 files changed, 14 insertions(+), 3 deletions(-)
diff --git a/include/linux/cgroup-defs.h b/include/linux/cgroup-defs.h index ae04035b6cbe..a2fcb3db6c52 100644 --- a/include/linux/cgroup-defs.h +++ b/include/linux/cgroup-defs.h @@ -315,6 +315,7 @@ 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 a06b45272411..a77ba9a83bab 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) @@ -535,7 +537,10 @@ void __cgroup_account_cputime_field(struct cgroup *cgrp,
switch (index) { case CPUTIME_USER: + rstatc->bstat.cputime.utime += delta_exec; + break; case CPUTIME_NICE: + rstatc->bstat.ntime += delta_exec; rstatc->bstat.cputime.utime += delta_exec; break; case CPUTIME_SYSTEM: @@ -591,6 +596,7 @@ 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]; } }
@@ -608,13 +614,14 @@ 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 */ @@ -622,16 +629,19 @@ 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); + "system_usec %llu\n" + "nice_usec %llu\n", + usage, utime, stime, ntime);
cgroup_force_idle_show(seq, &cgrp->bstat); }