Messages in this thread Patch in this message |  | | | Date | Fri, 04 Sep 2009 19:55:29 -0400 | | From | Steven Rostedt <> | | Subject | [PATCH 02/18] ring-buffer: do not swap buffers during a commit |
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From: Steven Rostedt <srostedt@redhat.com>
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> --- 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 79d6012..2878bd4 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; } -- 1.6.3.3 --
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