From 71d078803ccbc020ae3b640293a40a86691b9151 Mon Sep 17 00:00:00 2001 From: Changwoo Min Date: Tue, 4 Mar 2025 19:49:00 +0900 Subject: [PATCH] sched_ext: Add trace point to track sched_ext core events Add tracing support to track sched_ext core events (/sched_ext/sched_ext_event). This may be useful for debugging sched_ext schedulers that trigger a particular event. The trace point can be used as other trace points, so it can be used in, for example, `perf trace` and BPF programs, as follows: ====== $> sudo perf trace -e sched_ext:sched_ext_event --filter 'name == "SCX_EV_ENQ_SLICE_DFL"' ====== ====== struct tp_sched_ext_event { struct trace_entry ent; u32 __data_loc_name; s64 delta; }; SEC("tracepoint/sched_ext/sched_ext_event") int rtp_add_event(struct tp_sched_ext_event *ctx) { char event_name[128]; unsigned short offset = ctx->__data_loc_name & 0xFFFF; bpf_probe_read_str((void *)event_name, 128, (char *)ctx + offset); bpf_printk("name %s delta %lld", event_name, ctx->delta); return 0; } ====== Signed-off-by: Changwoo Min Acked-by: Andrea Righi Signed-off-by: Tejun Heo --- include/trace/events/sched_ext.h | 19 +++++++++++++++++++ kernel/sched/ext.c | 2 ++ 2 files changed, 21 insertions(+) diff --git a/include/trace/events/sched_ext.h b/include/trace/events/sched_ext.h index fe19da7315a9..50e4b712735a 100644 --- a/include/trace/events/sched_ext.h +++ b/include/trace/events/sched_ext.h @@ -26,6 +26,25 @@ TRACE_EVENT(sched_ext_dump, ) ); +TRACE_EVENT(sched_ext_event, + TP_PROTO(const char *name, __s64 delta), + TP_ARGS(name, delta), + + TP_STRUCT__entry( + __string(name, name) + __field( __s64, delta ) + ), + + TP_fast_assign( + __assign_str(name); + __entry->delta = delta; + ), + + TP_printk("name %s delta %lld", + __get_str(name), __entry->delta + ) +); + #endif /* _TRACE_SCHED_EXT_H */ /* This part must be outside protection */ diff --git a/kernel/sched/ext.c b/kernel/sched/ext.c index 686629a860f3..debcd1cf2de9 100644 --- a/kernel/sched/ext.c +++ b/kernel/sched/ext.c @@ -1554,6 +1554,7 @@ static DEFINE_PER_CPU(struct scx_event_stats, event_stats_cpu); */ #define scx_add_event(name, cnt) do { \ this_cpu_add(event_stats_cpu.name, cnt); \ + trace_sched_ext_event(#name, cnt); \ } while(0) /** @@ -1565,6 +1566,7 @@ static DEFINE_PER_CPU(struct scx_event_stats, event_stats_cpu); */ #define __scx_add_event(name, cnt) do { \ __this_cpu_add(event_stats_cpu.name, cnt); \ + trace_sched_ext_event(#name, cnt); \ } while(0) /** -- 2.25.1