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| author | Steven Rostedt <srostedt@redhat.com> | 2009-09-02 10:56:15 -0400 |
|---|---|---|
| committer | Steven Rostedt <rostedt@goodmis.org> | 2009-09-04 11:22:47 -0400 |
| commit | 98277991a99734f3a31d638afb47d4484ac73e43 (patch) | |
| tree | 6688cb3c43562d6bd7b67961478ac337297064e5 | |
| parent | 41b6a95d693319f804607b559893fbbd27498548 (diff) | |
| download | blackbird-obmc-linux-98277991a99734f3a31d638afb47d4484ac73e43.tar.gz blackbird-obmc-linux-98277991a99734f3a31d638afb47d4484ac73e43.zip | |
ring-buffer: do not swap buffers during a commit
If a commit is taking place on a CPU ring buffer, do not allow it to
be swapped. Return -EBUSY when this is detected instead.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| -rw-r--r-- | kernel/trace/ring_buffer.c | 11 |
1 files changed, 9 insertions, 2 deletions
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index 79d6012bb1f1..2878bd43a59c 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -3519,16 +3519,23 @@ int ring_buffer_swap_cpu(struct ring_buffer *buffer_a, atomic_inc(&cpu_buffer_a->record_disabled); atomic_inc(&cpu_buffer_b->record_disabled); + ret = -EBUSY; + if (local_read(&cpu_buffer_a->committing)) + goto out_dec; + if (local_read(&cpu_buffer_b->committing)) + goto out_dec; + buffer_a->buffers[cpu] = cpu_buffer_b; buffer_b->buffers[cpu] = cpu_buffer_a; cpu_buffer_b->buffer = buffer_a; cpu_buffer_a->buffer = buffer_b; + ret = 0; + +out_dec: atomic_dec(&cpu_buffer_a->record_disabled); atomic_dec(&cpu_buffer_b->record_disabled); - - ret = 0; out: return ret; } |
