From d41bf8c9deaed1a90b18d3ffc5639d4c19f0259a Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Mon, 23 Oct 2017 16:18:27 -0700 Subject: cgroup, sched: Move basic cpu stats from cgroup.stat to cpu.stat The basic cpu stat is currently shown with "cpu." prefix in cgroup.stat, and the same information is duplicated in cpu.stat when cpu controller is enabled. This is ugly and not very scalable as we want to expand the coverage of stat information which is always available. This patch makes cgroup core always create "cpu.stat" file and show the basic cpu stat there and calls the cpu controller to show the extra stats when enabled. This ensures that the same information isn't presented in multiple places and makes future expansion of basic stats easier. Signed-off-by: Tejun Heo Acked-by: Peter Zijlstra (Intel) --- kernel/cgroup/cgroup-internal.h | 1 + kernel/cgroup/cgroup.c | 60 +++++++++++++++++++++++++++++++++++++++-- kernel/cgroup/stat.c | 10 +++---- kernel/sched/core.c | 13 +++------ 4 files changed, 68 insertions(+), 16 deletions(-) (limited to 'kernel') diff --git a/kernel/cgroup/cgroup-internal.h b/kernel/cgroup/cgroup-internal.h index fa642c99586a..4dc317090920 100644 --- a/kernel/cgroup/cgroup-internal.h +++ b/kernel/cgroup/cgroup-internal.h @@ -205,6 +205,7 @@ int cgroup_task_count(const struct cgroup *cgrp); void cgroup_stat_flush(struct cgroup *cgrp); int cgroup_stat_init(struct cgroup *cgrp); void cgroup_stat_exit(struct cgroup *cgrp); +void cgroup_stat_show_cputime(struct seq_file *seq); void cgroup_stat_boot(void); /* diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c index 7975b20f1fd1..d9773e49a1b4 100644 --- a/kernel/cgroup/cgroup.c +++ b/kernel/cgroup/cgroup.c @@ -463,6 +463,28 @@ static struct cgroup_subsys_state *cgroup_css(struct cgroup *cgrp, return &cgrp->self; } +/** + * cgroup_tryget_css - try to get a cgroup's css for the specified subsystem + * @cgrp: the cgroup of interest + * @ss: the subsystem of interest + * + * Find and get @cgrp's css assocaited with @ss. If the css doesn't exist + * or is offline, %NULL is returned. + */ +static struct cgroup_subsys_state *cgroup_tryget_css(struct cgroup *cgrp, + struct cgroup_subsys *ss) +{ + struct cgroup_subsys_state *css; + + rcu_read_lock(); + css = cgroup_css(cgrp, ss); + if (!css || !css_tryget_online(css)) + css = NULL; + rcu_read_unlock(); + + return css; +} + /** * cgroup_e_css - obtain a cgroup's effective css for the specified subsystem * @cgrp: the cgroup of interest @@ -3311,11 +3333,40 @@ static int cgroup_stat_show(struct seq_file *seq, void *v) seq_printf(seq, "nr_dying_descendants %d\n", cgroup->nr_dying_descendants); - cgroup_stat_show_cputime(seq, "cpu."); - return 0; } +static int __maybe_unused cgroup_extra_stat_show(struct seq_file *seq, + struct cgroup *cgrp, int ssid) +{ + struct cgroup_subsys *ss = cgroup_subsys[ssid]; + struct cgroup_subsys_state *css; + int ret; + + if (!ss->css_extra_stat_show) + return 0; + + css = cgroup_tryget_css(cgrp, ss); + if (!css) + return 0; + + ret = ss->css_extra_stat_show(seq, css); + css_put(css); + return ret; +} + +static int cpu_stat_show(struct seq_file *seq, void *v) +{ + struct cgroup *cgrp = seq_css(seq)->cgroup; + int ret = 0; + + cgroup_stat_show_cputime(seq); +#ifdef CONFIG_CGROUP_SCHED + ret = cgroup_extra_stat_show(seq, cgrp, cpu_cgrp_id); +#endif + return ret; +} + static int cgroup_file_open(struct kernfs_open_file *of) { struct cftype *cft = of->kn->priv; @@ -4423,6 +4474,11 @@ static struct cftype cgroup_base_files[] = { .name = "cgroup.stat", .seq_show = cgroup_stat_show, }, + { + .name = "cpu.stat", + .flags = CFTYPE_NOT_ON_ROOT, + .seq_show = cpu_stat_show, + }, { } /* terminate */ }; diff --git a/kernel/cgroup/stat.c b/kernel/cgroup/stat.c index 9cce79e89320..133b465691d6 100644 --- a/kernel/cgroup/stat.c +++ b/kernel/cgroup/stat.c @@ -256,7 +256,7 @@ void __cgroup_account_cputime_field(struct cgroup *cgrp, cgroup_cpu_stat_account_end(cgrp, cstat); } -void cgroup_stat_show_cputime(struct seq_file *seq, const char *prefix) +void cgroup_stat_show_cputime(struct seq_file *seq) { struct cgroup *cgrp = seq_css(seq)->cgroup; u64 usage, utime, stime; @@ -278,10 +278,10 @@ void cgroup_stat_show_cputime(struct seq_file *seq, const char *prefix) do_div(utime, NSEC_PER_USEC); do_div(stime, NSEC_PER_USEC); - seq_printf(seq, "%susage_usec %llu\n" - "%suser_usec %llu\n" - "%ssystem_usec %llu\n", - prefix, usage, prefix, utime, prefix, stime); + seq_printf(seq, "usage_usec %llu\n" + "user_usec %llu\n" + "system_usec %llu\n", + usage, utime, stime); } int cgroup_stat_init(struct cgroup *cgrp) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index ad255162a830..0b3eec389552 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -6678,13 +6678,12 @@ static struct cftype cpu_legacy_files[] = { { } /* Terminate */ }; -static int cpu_stat_show(struct seq_file *sf, void *v) +static int cpu_extra_stat_show(struct seq_file *sf, + struct cgroup_subsys_state *css) { - cgroup_stat_show_cputime(sf, ""); - #ifdef CONFIG_CFS_BANDWIDTH { - struct task_group *tg = css_tg(seq_css(sf)); + struct task_group *tg = css_tg(css); struct cfs_bandwidth *cfs_b = &tg->cfs_bandwidth; u64 throttled_usec; @@ -6817,11 +6816,6 @@ static ssize_t cpu_max_write(struct kernfs_open_file *of, #endif static struct cftype cpu_files[] = { - { - .name = "stat", - .flags = CFTYPE_NOT_ON_ROOT, - .seq_show = cpu_stat_show, - }, #ifdef CONFIG_FAIR_GROUP_SCHED { .name = "weight", @@ -6852,6 +6846,7 @@ struct cgroup_subsys cpu_cgrp_subsys = { .css_online = cpu_cgroup_css_online, .css_released = cpu_cgroup_css_released, .css_free = cpu_cgroup_css_free, + .css_extra_stat_show = cpu_extra_stat_show, .fork = cpu_cgroup_fork, .can_attach = cpu_cgroup_can_attach, .attach = cpu_cgroup_attach, -- cgit v1.2.3