diff options
| author | Zheng Yejian <zhengyejian1@huawei.com> | 2023-09-06 16:19:30 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-10-10 21:46:40 +0200 |
| commit | 05264d6551e1f696208a79bc174c34c2dfb71d49 (patch) | |
| tree | 47c58b0208f4f9eb695a2dc816fff85eb0313e16 /kernel | |
| parent | 1d28224d49f3c9fb80e043e7b4ed8c7abc1874d0 (diff) | |
ring-buffer: Avoid softlockup in ring_buffer_resize()
[ Upstream commit f6bd2c92488c30ef53b5bd80c52f0a7eee9d545a ]
When user resize all trace ring buffer through file 'buffer_size_kb',
then in ring_buffer_resize(), kernel allocates buffer pages for each
cpu in a loop.
If the kernel preemption model is PREEMPT_NONE and there are many cpus
and there are many buffer pages to be allocated, it may not give up cpu
for a long time and finally cause a softlockup.
To avoid it, call cond_resched() after each cpu buffer allocation.
Link: https://lore.kernel.org/linux-trace-kernel/20230906081930.3939106-1-zhengyejian1@huawei.com
Cc: <mhiramat@kernel.org>
Signed-off-by: Zheng Yejian <zhengyejian1@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/trace/ring_buffer.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index 445475c229b3..2a4fb4f1e3ca 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -1821,6 +1821,8 @@ int ring_buffer_resize(struct ring_buffer *buffer, unsigned long size, err = -ENOMEM; goto out_err; } + + cond_resched(); } get_online_cpus(); |