perf: fix perf_event_context->time
authorSong Liu <song@kernel.org>
Mon, 13 Mar 2023 17:16:08 +0000 (10:16 -0700)
committerPeter Zijlstra <peterz@infradead.org>
Wed, 15 Mar 2023 20:49:46 +0000 (21:49 +0100)
commitbaf1b12a67f5b24f395baca03e442ce27cab0c18
treef9712ff14ca14f51daf9ec21bc3b534f55040fcc
parenteb81a2ed4f52be831c9fb879752d89645a312c13
perf: fix perf_event_context->time

Time readers rely on perf_event_context->[time|timestamp|timeoffset] to get
accurate time_enabled and time_running for an event. The difference between
ctx->timestamp and ctx->time is the among of time when the context is not
enabled. __update_context_time(ctx, false) is used to increase timestamp,
but not time. Therefore, it should only be called in ctx_sched_in() when
EVENT_TIME was not enabled.

Fixes: 09f5e7dc7ad7 ("perf: Fix perf_event_read_local() time")
Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/r/20230313171608.298734-1-song@kernel.org
kernel/events/core.c