From 95b99f353cf3d9d753796975f2093b13f75e0fbd Mon Sep 17 00:00:00 2001 From: Wei Yang Date: Sat, 8 Jan 2022 00:38:17 +0000 Subject: [PATCH] cgroup: rstat: retrieve current bstat to delta directly Instead of retrieve current bstat to cur and copy it to delta, let's use delta directly. This saves one copy operation and has the same code convention as propagating delta to parent. Signed-off-by: Wei Yang Signed-off-by: Tejun Heo --- kernel/cgroup/rstat.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/kernel/cgroup/rstat.c b/kernel/cgroup/rstat.c index 0b32fa62e93c..29ea74f0eab3 100644 --- a/kernel/cgroup/rstat.c +++ b/kernel/cgroup/rstat.c @@ -315,7 +315,7 @@ static void cgroup_base_stat_flush(struct cgroup *cgrp, int cpu) { struct cgroup_rstat_cpu *rstatc = cgroup_rstat_cpu(cgrp, cpu); struct cgroup *parent = cgroup_parent(cgrp); - struct cgroup_base_stat cur, delta; + struct cgroup_base_stat delta; unsigned seq; /* Root-level stats are sourced from system-wide CPU stats */ @@ -325,11 +325,10 @@ static void cgroup_base_stat_flush(struct cgroup *cgrp, int cpu) /* fetch the current per-cpu values */ do { seq = __u64_stats_fetch_begin(&rstatc->bsync); - cur = rstatc->bstat; + delta = rstatc->bstat; } while (__u64_stats_fetch_retry(&rstatc->bsync, seq)); /* propagate percpu delta to global */ - delta = cur; cgroup_base_stat_sub(&delta, &rstatc->last_bstat); cgroup_base_stat_add(&cgrp->bstat, &delta); cgroup_base_stat_add(&rstatc->last_bstat, &delta);