From: Steven Rostedt <rostedt@goodmis.org>
To: linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>,
Mark Rutland <mark.rutland@arm.com>,
Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
Andrew Morton <akpm@linux-foundation.org>,
Tzvetomir Stoyanov <tz.stoyanov@gmail.com>,
Vincent Donnefort <vdonnefort@google.com>,
Kent Overstreet <kent.overstreet@gmail.com>
Subject: [PATCH v4 07/15] ring-buffer: Do no swap cpu buffers if order is different
Date: Fri, 15 Dec 2023 12:55:09 -0500 [thread overview]
Message-ID: <20231215175545.246121768@goodmis.org> (raw)
In-Reply-To: 20231215175502.106587604@goodmis.org
From: "Steven Rostedt (Google)" <rostedt@goodmis.org>
As all the subbuffer order (subbuffer sizes) must be the same throughout
the ring buffer, check the order of the buffers that are doing a CPU
buffer swap in ring_buffer_swap_cpu() to make sure they are the same.
If the are not the same, then fail to do the swap, otherwise the ring
buffer will think the CPU buffer has a specific subbuffer size when it
does not.
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
---
kernel/trace/ring_buffer.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index dd03887a4737..695b64fbc1cb 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -5350,6 +5350,9 @@ int ring_buffer_swap_cpu(struct trace_buffer *buffer_a,
if (cpu_buffer_a->nr_pages != cpu_buffer_b->nr_pages)
goto out;
+ if (buffer_a->subbuf_order != buffer_b->subbuf_order)
+ goto out;
+
ret = -EAGAIN;
if (atomic_read(&buffer_a->record_disabled))
--
2.42.0
next prev parent reply other threads:[~2023-12-15 17:54 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-12-15 17:55 [PATCH v4 00/15] ring-buffer/tracing: Allow ring buffer to have bigger sub buffers Steven Rostedt
2023-12-15 17:55 ` [PATCH v4 01/15] ring-buffer: Refactor ring buffer implementation Steven Rostedt
2023-12-15 17:55 ` [PATCH v4 02/15] ring-buffer: Page size per ring buffer Steven Rostedt
2023-12-15 17:55 ` [PATCH v4 03/15] ring-buffer: Add interface for configuring trace sub buffer size Steven Rostedt
2023-12-15 17:55 ` [PATCH v4 04/15] ring-buffer: Set new size of the ring buffer sub page Steven Rostedt
2023-12-15 17:55 ` [PATCH v4 05/15] ring-buffer: Read and write to ring buffers with custom sub buffer size Steven Rostedt
2023-12-15 17:55 ` [PATCH v4 06/15] ring-buffer: Clear pages on error in ring_buffer_subbuf_order_set() failure Steven Rostedt
2023-12-15 17:55 ` Steven Rostedt [this message]
2023-12-15 17:55 ` [PATCH v4 08/15] ring-buffer: Make sure the spare sub buffer used for reads has same size Steven Rostedt
2023-12-15 17:55 ` [PATCH v4 09/15] tracing: Update snapshot order along with main buffer order Steven Rostedt
2023-12-15 17:55 ` [PATCH v4 10/15] tracing: Stop the tracing while changing the ring buffer subbuf size Steven Rostedt
2023-12-15 17:55 ` [PATCH v4 11/15] ring-buffer: Keep the same size when updating the order Steven Rostedt
2023-12-15 17:55 ` [PATCH v4 12/15] ring-buffer: Just update the subbuffers when changing their allocation order Steven Rostedt
2023-12-15 17:55 ` [PATCH v4 13/15] ring-buffer: Add documentation on the buffer_subbuf_order file Steven Rostedt
2023-12-15 17:55 ` [PATCH v4 14/15] ringbuffer/selftest: Add basic selftest to test changing subbuf order Steven Rostedt
2023-12-15 17:55 ` [PATCH v4 15/15] tracing: Update subbuffer with kilobytes not page order 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=20231215175545.246121768@goodmis.org \
--to=rostedt@goodmis.org \
--cc=akpm@linux-foundation.org \
--cc=kent.overstreet@gmail.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-trace-kernel@vger.kernel.org \
--cc=mark.rutland@arm.com \
--cc=mathieu.desnoyers@efficios.com \
--cc=mhiramat@kernel.org \
--cc=tz.stoyanov@gmail.com \
--cc=vdonnefort@google.com \
/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;
as well as URLs for NNTP newsgroup(s).