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author | Steven Rostedt <srostedt@redhat.com> | 2009-05-11 16:08:00 -0400 |
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committer | Steven Rostedt <rostedt@goodmis.org> | 2009-05-11 23:12:34 -0400 |
commit | 0f0c85fc80adbbd2265d89867d743f929d516805 (patch) | |
tree | 0095c5a83727863eb38027c41b9a0cd74c1d283d /kernel/trace/ring_buffer.c | |
parent | be957c447f7233a67904a1b11eb3ab61e702bf4d (diff) | |
download | op-kernel-dev-0f0c85fc80adbbd2265d89867d743f929d516805.zip op-kernel-dev-0f0c85fc80adbbd2265d89867d743f929d516805.tar.gz |
ring-buffer: small optimizations
Doing some small changes in the fast path of the ring buffer recording
saves over 3% in the ring-buffer-benchmark test.
[ Impact: a little faster ring buffer recording ]
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Diffstat (limited to 'kernel/trace/ring_buffer.c')
-rw-r--r-- | kernel/trace/ring_buffer.c | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index 493cba4..f452de2 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -1000,7 +1000,7 @@ rb_event_index(struct ring_buffer_event *event) return (addr & ~PAGE_MASK) - (PAGE_SIZE - BUF_PAGE_SIZE); } -static int +static inline int rb_is_commit(struct ring_buffer_per_cpu *cpu_buffer, struct ring_buffer_event *event) { @@ -1423,9 +1423,9 @@ rb_reserve_next_event(struct ring_buffer_per_cpu *cpu_buffer, * also be made. But only the entry that did the actual * commit will be something other than zero. */ - if (cpu_buffer->tail_page == cpu_buffer->commit_page && - rb_page_write(cpu_buffer->tail_page) == - rb_commit_index(cpu_buffer)) { + if (likely(cpu_buffer->tail_page == cpu_buffer->commit_page && + rb_page_write(cpu_buffer->tail_page) == + rb_commit_index(cpu_buffer))) { delta = ts - cpu_buffer->write_stamp; @@ -1436,7 +1436,7 @@ rb_reserve_next_event(struct ring_buffer_per_cpu *cpu_buffer, if (unlikely(ts < cpu_buffer->write_stamp)) delta = 0; - if (test_time_stamp(delta)) { + else if (unlikely(test_time_stamp(delta))) { commit = rb_add_time_stamp(cpu_buffer, &ts, &delta); @@ -1470,7 +1470,7 @@ rb_reserve_next_event(struct ring_buffer_per_cpu *cpu_buffer, * If the timestamp was commited, make the commit our entry * now so that we will update it when needed. */ - if (commit) + if (unlikely(commit)) rb_set_commit_event(cpu_buffer, event); else if (!rb_is_commit(cpu_buffer, event)) delta = 0; |