From: Steven Rostedt <rostedt@goodmis.org>
To: linux-kernel@vger.kernel.org
Cc: Ingo Molnar <mingo@kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
stable@vger.kernel.org
Subject: [for-next][PATCH 04/15] ring-buffer: Check pending waiters when doing wake ups as well
Date: Thu, 29 Sep 2022 18:55:46 -0400 [thread overview]
Message-ID: <20220929225635.826306562@goodmis.org> (raw)
In-Reply-To: 20220929225542.784716766@goodmis.org
From: "Steven Rostedt (Google)" <rostedt@goodmis.org>
The wake up waiters only checks the "wakeup_full" variable and not the
"full_waiters_pending". The full_waiters_pending is set when a waiter is
added to the wait queue. The wakeup_full is only set when an event is
triggered, and it clears the full_waiters_pending to avoid multiple calls
to irq_work_queue().
The irq_work callback really needs to check both wakeup_full as well as
full_waiters_pending such that this code can be used to wake up waiters
when a file is closed that represents the ring buffer and the waiters need
to be woken up.
Link: https://lkml.kernel.org/r/20220927231824.209460321@goodmis.org
Cc: stable@vger.kernel.org
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Fixes: 15693458c4bc0 ("tracing/ring-buffer: Move poll wake ups into ring buffer code")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
---
kernel/trace/ring_buffer.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index 02db92c9eb1b..5a7d818ca3ea 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -917,8 +917,9 @@ static void rb_wake_up_waiters(struct irq_work *work)
struct rb_irq_work *rbwork = container_of(work, struct rb_irq_work, work);
wake_up_all(&rbwork->waiters);
- if (rbwork->wakeup_full) {
+ if (rbwork->full_waiters_pending || rbwork->wakeup_full) {
rbwork->wakeup_full = false;
+ rbwork->full_waiters_pending = false;
wake_up_all(&rbwork->full_waiters);
}
}
--
2.35.1
next prev parent reply other threads:[~2022-09-29 22:55 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20220929225542.784716766@goodmis.org>
2022-09-29 22:55 ` [for-next][PATCH 02/15] ring-buffer: Allow splice to read previous partially read pages Steven Rostedt
2022-09-29 22:55 ` [for-next][PATCH 03/15] ring-buffer: Have the shortest_full queue be the shortest not longest Steven Rostedt
2022-09-29 22:55 ` Steven Rostedt [this message]
2022-09-29 22:55 ` [for-next][PATCH 05/15] ring-buffer: Add ring_buffer_wake_waiters() Steven Rostedt
2022-09-29 22:55 ` [for-next][PATCH 06/15] tracing: Wake up ring buffer waiters on closing of the file Steven Rostedt
2022-09-29 22:55 ` [for-next][PATCH 07/15] tracing: Add ioctl() to force ring buffer waiters to wake up Steven Rostedt
2022-09-29 22:55 ` [for-next][PATCH 08/15] tracing: Wake up waiters when tracing is disabled Steven Rostedt
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