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: [PATCH 1/5] ring-buffer: Have the shortest_full queue be the shortest not longest
Date: Tue, 27 Sep 2022 19:15:24 -0400 [thread overview]
Message-ID: <20220927231823.718039222@goodmis.org> (raw)
In-Reply-To: <20220927231523.298295015@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.
Cc: stable@vger.kernel.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:[~2022-09-27 23:17 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-09-27 23:15 [PATCH 0/5] tracing: Handle ring buffer waiters Steven Rostedt
2022-09-27 23:15 ` Steven Rostedt [this message]
2022-09-27 23:15 ` [PATCH 2/5] ring-buffer: Check pending waiters when doing wake ups as well Steven Rostedt
2022-09-27 23:15 ` [PATCH 3/5] ring-buffer: Add ring_buffer_wake_waiters() Steven Rostedt
2022-09-27 23:15 ` [PATCH 4/5] tracing: Wake up ring buffer waiters on closing of the file Steven Rostedt
2022-09-27 23:15 ` [PATCH 5/5] tracing: Add ioctl() to force ring buffer waiters to wake up Steven Rostedt
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20220927231823.718039222@goodmis.org \
--to=rostedt@goodmis.org \
--cc=akpm@linux-foundation.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@kernel.org \
--cc=stable@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox
all inboxes | Powered by JetHome®