From: Steven Rostedt <rostedt@goodmis.org>
To: linux-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: [for-next][PATCH 07/16] ring-buffer: Do no swap cpu buffers if order is different
Date: Thu, 21 Dec 2023 11:10:31 -0500 [thread overview]
Message-ID: <20231221161104.201002261@goodmis.org> (raw)
In-Reply-To: 20231221161024.478795180@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.
Link: https://lore.kernel.org/linux-trace-kernel/20231219185629.467894710@goodmis.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Tzvetomir Stoyanov <tz.stoyanov@gmail.com>
Cc: Vincent Donnefort <vdonnefort@google.com>
Cc: Kent Overstreet <kent.overstreet@gmail.com>
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 3c11e8e811ed..fdcd171b09b5 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -5417,6 +5417,9 @@ 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:[~2023-12-21 16:10 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-12-21 16:10 [for-next][PATCH 00/16] tracing: Add dynamic sub-buffer size for 6.8 Steven Rostedt
2023-12-21 16:10 ` [for-next][PATCH 01/16] ring-buffer: Have ring_buffer_print_page_header() be able to access ring_buffer_iter Steven Rostedt
2023-12-21 16:10 ` [for-next][PATCH 02/16] ring-buffer: Page size per ring buffer Steven Rostedt
2023-12-21 16:10 ` [for-next][PATCH 03/16] ring-buffer: Add interface for configuring trace sub buffer size Steven Rostedt
2023-12-21 16:10 ` [for-next][PATCH 04/16] ring-buffer: Set new size of the ring buffer sub page Steven Rostedt
2023-12-21 16:10 ` [for-next][PATCH 05/16] ring-buffer: Read and write to ring buffers with custom sub buffer size Steven Rostedt
2023-12-21 16:10 ` [for-next][PATCH 06/16] ring-buffer: Clear pages on error in ring_buffer_subbuf_order_set() failure Steven Rostedt
2023-12-21 16:10 ` Steven Rostedt [this message]
2023-12-21 16:10 ` [for-next][PATCH 08/16] ring-buffer: Make sure the spare sub buffer used for reads has same size Steven Rostedt
2023-12-21 16:10 ` [for-next][PATCH 09/16] tracing: Update snapshot order along with main buffer order Steven Rostedt
2023-12-21 16:10 ` [for-next][PATCH 10/16] tracing: Stop the tracing while changing the ring buffer subbuf size Steven Rostedt
2023-12-21 16:10 ` [for-next][PATCH 11/16] ring-buffer: Keep the same size when updating the order Steven Rostedt
2023-12-21 16:10 ` [for-next][PATCH 12/16] ring-buffer: Just update the subbuffers when changing their allocation order Steven Rostedt
2023-12-21 16:10 ` [for-next][PATCH 13/16] ring-buffer: Add documentation on the buffer_subbuf_order file Steven Rostedt
2023-12-21 16:10 ` [for-next][PATCH 14/16] ringbuffer/selftest: Add basic selftest to test changing subbuf order Steven Rostedt
2023-12-21 16:10 ` [for-next][PATCH 15/16] tracing: Update subbuffer with kilobytes not page order Steven Rostedt
2023-12-21 16:10 ` [for-next][PATCH 16/16] ring-buffer: Use subbuf_order for buffer page masking Steven Rostedt
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