sched/cpuacct: Show all possible CPUs in cpuacct output (5ca3726a) · Commits · 戴 / test

Current code show stats of online CPUs in cpuacct.statcpus, show stats of present cpus in cpuacct.usage(_percpu), and using present CPUs for setting cpuacct.usage. It will cause inconsistent result when a CPU is online or offline or hotpluged. We should always use possible CPUs to avoid above problem. Here are the contents of a cpuacct.usage_percpu sysfs file, on a 4 CPU system with maxcpus=32: Before the patch: # cat cpuacct.usage_percpu 2456565 411435 1052897 832584 After the patch: # cat cpuacct.usage_percpu 2456565 411435 1052897 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Suggested-by:

Peter Zijlstra <peterz@infradead.org> Signed-off-by:

Zhao Lei <zhaolei@cn.fujitsu.com> Signed-off-by:

Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Tejun Heo <htejun@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/a11d56cef12d0b4807f8be3a46bf9798c3014d59.1458635566.git.zhaolei@cn.fujitsu.com Signed-off-by:

Ingo Molnar <mingo@kernel.org>

kernel/sched/cpuacct.c

+5 −5

Original line number	Diff line number	Diff line
		@@ -138,7 +138,7 @@ static u64 cpuusage_read(struct cgroup_subsys_state css, struct cftype cft)
		u64 totalcpuusage = 0;
		int i;

		for_each_present_cpu(i)
		for_each_possible_cpu(i)
		totalcpuusage += cpuacct_cpuusage_read(ca, i);

		return totalcpuusage;
		@@ -159,7 +159,7 @@ static int cpuusage_write(struct cgroup_subsys_state css, struct cftype cft,
		goto out;
		}

		for_each_present_cpu(i)
		for_each_possible_cpu(i)
		cpuacct_cpuusage_write(ca, i, 0);

		out:
		@@ -172,7 +172,7 @@ static int cpuacct_percpu_seq_show(struct seq_file m, void V)
		u64 percpu;
		int i;

		for_each_present_cpu(i) {
		for_each_possible_cpu(i) {
		percpu = cpuacct_cpuusage_read(ca, i);
		seq_printf(m, "%llu ", (unsigned long long) percpu);
		}
		@@ -191,7 +191,7 @@ static int cpuacct_stats_show(struct seq_file sf, void v)
		int cpu;
		s64 val = 0;

		for_each_online_cpu(cpu) {
		for_each_possible_cpu(cpu) {
		struct kernel_cpustat *kcpustat = per_cpu_ptr(ca->cpustat, cpu);
		val += kcpustat->cpustat[CPUTIME_USER];
		val += kcpustat->cpustat[CPUTIME_NICE];
		@@ -200,7 +200,7 @@ static int cpuacct_stats_show(struct seq_file sf, void v)
		seq_printf(sf, "%s %lld\n", cpuacct_stat_desc[CPUACCT_STAT_USER], val);

		val = 0;
		for_each_online_cpu(cpu) {
		for_each_possible_cpu(cpu) {
		struct kernel_cpustat *kcpustat = per_cpu_ptr(ca->cpustat, cpu);
		val += kcpustat->cpustat[CPUTIME_SYSTEM];
		val += kcpustat->cpustat[CPUTIME_IRQ];

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