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perf/ring_buffer: Allow the EPOLLRDNORM flag for poll

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[ Upstream commit c96fff391c095c11dc87dab35be72dee7d217cde ]

The poll man page says POLLRDNORM is equivalent to POLLIN. For poll(),
it seems that if user sets pollfd with POLLRDNORM in userspace, perf_poll
will not return until timeout even if perf_output_wakeup called,
whereas POLLIN returns.

Fixes: 76369139ce ("perf: Split up buffer handling from core code")
Signed-off-by: Tao Chen <chen.dylane@linux.dev>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/20250314030036.2543180-1-chen.dylane@linux.dev
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Tao Chen 2025-03-14 11:00:36 +08:00 committed by Greg Kroah-Hartman
parent 4210ca861f
commit 214965d1a6
1 changed files with 1 additions and 1 deletions
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2
kernel/events/ring_buffer.c
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@ -19,7 +19,7 @@
static void perf_output_wakeup(struct perf_output_handle *handle)
{
atomic_set(&handle->rb->poll, EPOLLIN);
atomic_set(&handle->rb->poll, EPOLLIN | EPOLLRDNORM);
handle->event->pending_wakeup = 1;
irq_work_queue(&handle->event->pending_irq);