perf/core: Flush PMU internal buffers for per-CPU events
stable inclusion from stable-5.10.24 commit 82ad50c112f89ca0bc6e28b9e72dfc157996f6c6 bugzilla: 51348 -------------------------------- [ Upstream commit a5398bff ] Sometimes the PMU internal buffers have to be flushed for per-CPU events during a context switch, e.g., large PEBS. Otherwise, the perf tool may report samples in locations that do not belong to the process where the samples are processed in, because PEBS does not tag samples with PID/TID. The current code only flush the buffers for a per-task event. It doesn't check a per-CPU event. Add a new event state flag, PERF_ATTACH_SCHED_CB, to indicate that the PMU internal buffers have to be flushed for this event during a context switch. Add sched_cb_entry and perf_sched_cb_usages back to track the PMU/cpuctx which is required to be flushed. Only need to invoke the sched_task() for per-CPU events in this patch. The per-task events have been handled in perf_event_context_sched_in/out already. Fixes: 9c964efa ("perf/x86/intel: Drain the PEBS buffer during context switches") Reported-by:Gabriel Marin <gmx@google.com> Originally-by:
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