From 0297b80339d545045490716fa8591b215fdd9458 Mon Sep 17 00:00:00 2001 From: Dhaval Giani Date: Fri, 29 Feb 2008 10:02:44 +0530 Subject: [PATCH] sched: allow cpuacct stats to be reset Currently the schedstats implementation does not allow the statistics to be reset. This patch aims to allow that. echo 0 > cpuacct.usage resets the usage. Any other value is not allowed and returns -EINVAL. Signed-off-by: Dhaval Giani Signed-off-by: Ingo Molnar --- kernel/sched.c | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+) diff --git a/kernel/sched.c b/kernel/sched.c index e2f85c7a7476..e4bf4477aee5 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -8381,10 +8381,34 @@ static u64 cpuusage_read(struct cgroup *cgrp, struct cftype *cft) return totalcpuusage; } +static int cpuusage_write(struct cgroup *cgrp, struct cftype *cftype, + u64 reset) +{ + struct cpuacct *ca = cgroup_ca(cgrp); + int err = 0; + int i; + + if (reset) { + err = -EINVAL; + goto out; + } + + for_each_possible_cpu(i) { + u64 *cpuusage = percpu_ptr(ca->cpuusage, i); + + spin_lock_irq(&cpu_rq(i)->lock); + *cpuusage = 0; + spin_unlock_irq(&cpu_rq(i)->lock); + } +out: + return err; +} + static struct cftype files[] = { { .name = "usage", .read_uint = cpuusage_read, + .write_uint = cpuusage_write, }, }; -- 2.20.1