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 03/15] ring-buffer: Have the shortest_full queue be the shortest not longest
Date: Thu, 29 Sep 2022 18:55:45 -0400 [thread overview]
Message-ID: <20220929225635.339549783@goodmis.org> (raw)
In-Reply-To: 20220929225542.784716766@goodmis.org
From: "Steven Rostedt (Google)" <rostedt@goodmis.org>
The logic to know when the shortest waiters on the ring buffer should be
woken up or not has uses a less than instead of a greater than compare,
which causes the shortest_full to actually be the longest.
Link: https://lkml.kernel.org/r/20220927231823.718039222@goodmis.org
Cc: stable@vger.kernel.org
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Fixes: 2c2b0a78b3739 ("ring-buffer: Add percentage of ring buffer full to wake up reader")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
---
kernel/trace/ring_buffer.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index 6b145d48dfd1..02db92c9eb1b 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -1011,7 +1011,7 @@ int ring_buffer_wait(struct trace_buffer *buffer, int cpu, int full)
nr_pages = cpu_buffer->nr_pages;
dirty = ring_buffer_nr_dirty_pages(buffer, cpu);
if (!cpu_buffer->shortest_full ||
- cpu_buffer->shortest_full < full)
+ cpu_buffer->shortest_full > full)
cpu_buffer->shortest_full = full;
raw_spin_unlock_irqrestore(&cpu_buffer->reader_lock, flags);
if (!pagebusy &&
--
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 ` Steven Rostedt [this message]
2022-09-29 22:55 ` [for-next][PATCH 04/15] ring-buffer: Check pending waiters when doing wake ups as well Steven Rostedt
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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