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authorSteven Rostedt <srostedt@redhat.com>2009-05-11 16:08:00 -0400
committerSteven Rostedt <rostedt@goodmis.org>2009-05-11 23:12:34 -0400
commit0f0c85fc80adbbd2265d89867d743f929d516805 (patch)
tree0095c5a83727863eb38027c41b9a0cd74c1d283d /kernel/trace/ring_buffer.c
parentbe957c447f7233a67904a1b11eb3ab61e702bf4d (diff)
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.c12
1 files changed, 6 insertions, 6 deletions
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index 493cba46abc9..f452de2ce490 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)
1000 return (addr & ~PAGE_MASK) - (PAGE_SIZE - BUF_PAGE_SIZE); 1000 return (addr & ~PAGE_MASK) - (PAGE_SIZE - BUF_PAGE_SIZE);
1001} 1001}
1002 1002
1003static int 1003static inline int
1004rb_is_commit(struct ring_buffer_per_cpu *cpu_buffer, 1004rb_is_commit(struct ring_buffer_per_cpu *cpu_buffer,
1005 struct ring_buffer_event *event) 1005 struct ring_buffer_event *event)
1006{ 1006{
@@ -1423,9 +1423,9 @@ rb_reserve_next_event(struct ring_buffer_per_cpu *cpu_buffer,
1423 * also be made. But only the entry that did the actual 1423 * also be made. But only the entry that did the actual
1424 * commit will be something other than zero. 1424 * commit will be something other than zero.
1425 */ 1425 */
1426 if (cpu_buffer->tail_page == cpu_buffer->commit_page && 1426 if (likely(cpu_buffer->tail_page == cpu_buffer->commit_page &&
1427 rb_page_write(cpu_buffer->tail_page) == 1427 rb_page_write(cpu_buffer->tail_page) ==
1428 rb_commit_index(cpu_buffer)) { 1428 rb_commit_index(cpu_buffer))) {
1429 1429
1430 delta = ts - cpu_buffer->write_stamp; 1430 delta = ts - cpu_buffer->write_stamp;
1431 1431
@@ -1436,7 +1436,7 @@ rb_reserve_next_event(struct ring_buffer_per_cpu *cpu_buffer,
1436 if (unlikely(ts < cpu_buffer->write_stamp)) 1436 if (unlikely(ts < cpu_buffer->write_stamp))
1437 delta = 0; 1437 delta = 0;
1438 1438
1439 if (test_time_stamp(delta)) { 1439 else if (unlikely(test_time_stamp(delta))) {
1440 1440
1441 commit = rb_add_time_stamp(cpu_buffer, &ts, &delta); 1441 commit = rb_add_time_stamp(cpu_buffer, &ts, &delta);
1442 1442
@@ -1470,7 +1470,7 @@ rb_reserve_next_event(struct ring_buffer_per_cpu *cpu_buffer,
1470 * If the timestamp was commited, make the commit our entry 1470 * If the timestamp was commited, make the commit our entry
1471 * now so that we will update it when needed. 1471 * now so that we will update it when needed.
1472 */ 1472 */
1473 if (commit) 1473 if (unlikely(commit))
1474 rb_set_commit_event(cpu_buffer, event); 1474 rb_set_commit_event(cpu_buffer, event);
1475 else if (!rb_is_commit(cpu_buffer, event)) 1475 else if (!rb_is_commit(cpu_buffer, event))
1476 delta = 0; 1476 delta = 0;