From d0d1dd628527c77db2391ce0293c1ed344b2365f Mon Sep 17 00:00:00 2001 From: Namhyung Kim Date: Wed, 10 Feb 2021 17:33:26 +0900 Subject: perf core: Add PERF_COUNT_SW_CGROUP_SWITCHES event This patch adds a new software event to count context switches involving cgroup switches. So it's counted only if cgroups of previous and next tasks are different. Note that it only checks the cgroups in the perf_event subsystem. For cgroup v2, it shouldn't matter anyway. One can argue that we can do this by using existing sched_switch event with eBPF. But some systems might not have eBPF for some reason so I'd like to add this as a simple way. Signed-off-by: Namhyung Kim Signed-off-by: Peter Zijlstra (Intel) Link: https://lkml.kernel.org/r/20210210083327.22726-2-namhyung@kernel.org --- include/linux/perf_event.h | 7 +++++++ include/uapi/linux/perf_event.h | 1 + 2 files changed, 8 insertions(+) (limited to 'include') diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index 92d51a7beaea..8989b2b7268d 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -1218,6 +1218,13 @@ static inline void perf_event_task_sched_out(struct task_struct *prev, if (__perf_sw_enabled(PERF_COUNT_SW_CONTEXT_SWITCHES)) __perf_sw_event_sched(PERF_COUNT_SW_CONTEXT_SWITCHES, 1, 0); +#ifdef CONFIG_CGROUP_PERF + if (__perf_sw_enabled(PERF_COUNT_SW_CGROUP_SWITCHES) && + perf_cgroup_from_task(prev, NULL) != + perf_cgroup_from_task(next, NULL)) + __perf_sw_event_sched(PERF_COUNT_SW_CGROUP_SWITCHES, 1, 0); +#endif + if (static_branch_unlikely(&perf_sched_events)) __perf_event_task_sched_out(prev, next); } diff --git a/include/uapi/linux/perf_event.h b/include/uapi/linux/perf_event.h index 31b00e3b69c9..0b58970bab6b 100644 --- a/include/uapi/linux/perf_event.h +++ b/include/uapi/linux/perf_event.h @@ -112,6 +112,7 @@ enum perf_sw_ids { PERF_COUNT_SW_EMULATION_FAULTS = 8, PERF_COUNT_SW_DUMMY = 9, PERF_COUNT_SW_BPF_OUTPUT = 10, + PERF_COUNT_SW_CGROUP_SWITCHES = 11, PERF_COUNT_SW_MAX, /* non-ABI */ }; -- cgit v1.2.3-59-g8ed1b