diff options
| author | Steven Rostedt <srostedt@redhat.com> | 2009-11-17 08:43:01 -0500 |
|---|---|---|
| committer | Steven Rostedt <rostedt@goodmis.org> | 2009-11-17 08:43:01 -0500 |
| commit | 5a50e33cc916f6a81cb96f0f24f6a88c9ab78b79 (patch) | |
| tree | cc00c32414107ade5492be200fcb1bc882968cae /kernel/trace | |
| parent | 8b2a5dac7859dd1954095fce8b6445c3ceb36ef6 (diff) | |
ring-buffer: Move access to commit_page up into function used
With the change of the way we process commits. Where a commit only happens
at the outer most level, and that we don't need to worry about
a commit ending after the rb_start_commit() has been called, the code
use to grab the commit page before the tail page to prevent a possible
race. But this race no longer exists with the rb_start_commit()
rb_end_commit() interface.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Diffstat (limited to 'kernel/trace')
| -rw-r--r-- | kernel/trace/ring_buffer.c | 9 |
1 files changed, 3 insertions, 6 deletions
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index 3ffa502fb24..4b8293fa545 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -1785,9 +1785,9 @@ rb_reset_tail(struct ring_buffer_per_cpu *cpu_buffer, static struct ring_buffer_event * rb_move_tail(struct ring_buffer_per_cpu *cpu_buffer, unsigned long length, unsigned long tail, - struct buffer_page *commit_page, struct buffer_page *tail_page, u64 *ts) { + struct buffer_page *commit_page = cpu_buffer->commit_page; struct ring_buffer *buffer = cpu_buffer->buffer; struct buffer_page *next_page; int ret; @@ -1890,13 +1890,10 @@ static struct ring_buffer_event * __rb_reserve_next(struct ring_buffer_per_cpu *cpu_buffer, unsigned type, unsigned long length, u64 *ts) { - struct buffer_page *tail_page, *commit_page; + struct buffer_page *tail_page; struct ring_buffer_event *event; unsigned long tail, write; - commit_page = cpu_buffer->commit_page; - /* we just need to protect against interrupts */ - barrier(); tail_page = cpu_buffer->tail_page; write = local_add_return(length, &tail_page->write); @@ -1907,7 +1904,7 @@ __rb_reserve_next(struct ring_buffer_per_cpu *cpu_buffer, /* See if we shot pass the end of this buffer page */ if (write > BUF_PAGE_SIZE) return rb_move_tail(cpu_buffer, length, tail, - commit_page, tail_page, ts); + tail_page, ts); /* We reserved something on the buffer */ |