diff options
Diffstat (limited to 'kernel/cgroup/rstat.c')
| -rw-r--r-- | kernel/cgroup/rstat.c | 92 |
1 files changed, 86 insertions, 6 deletions
diff --git a/kernel/cgroup/rstat.c b/kernel/cgroup/rstat.c index 24b5c2ab5598..793ecff29038 100644 --- a/kernel/cgroup/rstat.c +++ b/kernel/cgroup/rstat.c @@ -3,6 +3,10 @@ #include <linux/sched/cputime.h> +#include <linux/bpf.h> +#include <linux/btf.h> +#include <linux/btf_ids.h> + static DEFINE_SPINLOCK(cgroup_rstat_lock); static DEFINE_PER_CPU(raw_spinlock_t, cgroup_rstat_cpu_lock); @@ -141,6 +145,31 @@ static struct cgroup *cgroup_rstat_cpu_pop_updated(struct cgroup *pos, return pos; } +/* + * A hook for bpf stat collectors to attach to and flush their stats. + * Together with providing bpf kfuncs for cgroup_rstat_updated() and + * cgroup_rstat_flush(), this enables a complete workflow where bpf progs that + * collect cgroup stats can integrate with rstat for efficient flushing. + * + * A static noinline declaration here could cause the compiler to optimize away + * the function. A global noinline declaration will keep the definition, but may + * optimize away the callsite. Therefore, __weak is needed to ensure that the + * call is still emitted, by telling the compiler that we don't know what the + * function might eventually be. + * + * __diag_* below are needed to dismiss the missing prototype warning. + */ +__diag_push(); +__diag_ignore_all("-Wmissing-prototypes", + "kfuncs which will be used in BPF programs"); + +__weak noinline void bpf_rstat_flush(struct cgroup *cgrp, + struct cgroup *parent, int cpu) +{ +} + +__diag_pop(); + /* see cgroup_rstat_flush() */ static void cgroup_rstat_flush_locked(struct cgroup *cgrp, bool may_sleep) __releases(&cgroup_rstat_lock) __acquires(&cgroup_rstat_lock) @@ -168,6 +197,7 @@ static void cgroup_rstat_flush_locked(struct cgroup *cgrp, bool may_sleep) struct cgroup_subsys_state *css; cgroup_base_stat_flush(pos, cpu); + bpf_rstat_flush(pos, cgroup_parent(pos), cpu); rcu_read_lock(); list_for_each_entry_rcu(css, &pos->rstat_css_list, @@ -310,6 +340,9 @@ static void cgroup_base_stat_add(struct cgroup_base_stat *dst_bstat, dst_bstat->cputime.utime += src_bstat->cputime.utime; dst_bstat->cputime.stime += src_bstat->cputime.stime; dst_bstat->cputime.sum_exec_runtime += src_bstat->cputime.sum_exec_runtime; +#ifdef CONFIG_SCHED_CORE + dst_bstat->forceidle_sum += src_bstat->forceidle_sum; +#endif } static void cgroup_base_stat_sub(struct cgroup_base_stat *dst_bstat, @@ -318,6 +351,9 @@ static void cgroup_base_stat_sub(struct cgroup_base_stat *dst_bstat, dst_bstat->cputime.utime -= src_bstat->cputime.utime; dst_bstat->cputime.stime -= src_bstat->cputime.stime; dst_bstat->cputime.sum_exec_runtime -= src_bstat->cputime.sum_exec_runtime; +#ifdef CONFIG_SCHED_CORE + dst_bstat->forceidle_sum -= src_bstat->forceidle_sum; +#endif } static void cgroup_base_stat_flush(struct cgroup *cgrp, int cpu) @@ -398,6 +434,11 @@ void __cgroup_account_cputime_field(struct cgroup *cgrp, case CPUTIME_SOFTIRQ: rstatc->bstat.cputime.stime += delta_exec; break; +#ifdef CONFIG_SCHED_CORE + case CPUTIME_FORCEIDLE: + rstatc->bstat.forceidle_sum += delta_exec; + break; +#endif default: break; } @@ -411,8 +452,9 @@ void __cgroup_account_cputime_field(struct cgroup *cgrp, * with how it is done by __cgroup_account_cputime_field for each bit of * cpu time attributed to a cgroup. */ -static void root_cgroup_cputime(struct task_cputime *cputime) +static void root_cgroup_cputime(struct cgroup_base_stat *bstat) { + struct task_cputime *cputime = &bstat->cputime; int i; cputime->stime = 0; @@ -438,6 +480,10 @@ static void root_cgroup_cputime(struct task_cputime *cputime) cputime->sum_exec_runtime += user; cputime->sum_exec_runtime += sys; cputime->sum_exec_runtime += cpustat[CPUTIME_STEAL]; + +#ifdef CONFIG_SCHED_CORE + bstat->forceidle_sum += cpustat[CPUTIME_FORCEIDLE]; +#endif } } @@ -445,27 +491,61 @@ void cgroup_base_stat_cputime_show(struct seq_file *seq) { struct cgroup *cgrp = seq_css(seq)->cgroup; u64 usage, utime, stime; - struct task_cputime cputime; + struct cgroup_base_stat bstat; +#ifdef CONFIG_SCHED_CORE + u64 forceidle_time; +#endif 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); +#ifdef CONFIG_SCHED_CORE + forceidle_time = cgrp->bstat.forceidle_sum; +#endif cgroup_rstat_flush_release(); } else { - root_cgroup_cputime(&cputime); - usage = cputime.sum_exec_runtime; - utime = cputime.utime; - stime = cputime.stime; + root_cgroup_cputime(&bstat); + usage = bstat.cputime.sum_exec_runtime; + utime = bstat.cputime.utime; + stime = bstat.cputime.stime; +#ifdef CONFIG_SCHED_CORE + forceidle_time = bstat.forceidle_sum; +#endif } do_div(usage, NSEC_PER_USEC); do_div(utime, NSEC_PER_USEC); do_div(stime, NSEC_PER_USEC); +#ifdef CONFIG_SCHED_CORE + do_div(forceidle_time, NSEC_PER_USEC); +#endif seq_printf(seq, "usage_usec %llu\n" "user_usec %llu\n" "system_usec %llu\n", usage, utime, stime); + +#ifdef CONFIG_SCHED_CORE + seq_printf(seq, "core_sched.force_idle_usec %llu\n", forceidle_time); +#endif +} + +/* Add bpf kfuncs for cgroup_rstat_updated() and cgroup_rstat_flush() */ +BTF_SET8_START(bpf_rstat_kfunc_ids) +BTF_ID_FLAGS(func, cgroup_rstat_updated) +BTF_ID_FLAGS(func, cgroup_rstat_flush, KF_SLEEPABLE) +BTF_SET8_END(bpf_rstat_kfunc_ids) + +static const struct btf_kfunc_id_set bpf_rstat_kfunc_set = { + .owner = THIS_MODULE, + .set = &bpf_rstat_kfunc_ids, +}; + +static int __init bpf_rstat_kfunc_init(void) +{ + return register_btf_kfunc_id_set(BPF_PROG_TYPE_TRACING, + &bpf_rstat_kfunc_set); } +late_initcall(bpf_rstat_kfunc_init); |