diff options
| author | Steven Rostedt <[email protected]> | 2011-01-13 15:46:17 -0800 |
|---|---|---|
| committer | Linus Torvalds <[email protected]> | 2011-01-13 17:32:36 -0800 |
| commit | e20e87795834f2f14cb53baf657b91d9c39f92c8 (patch) | |
| tree | 0ec2c10b0ed4cb572c73153b56c017db536bc056 /kernel/trace/trace_workqueue.c | |
| parent | 088e54658f559a13c2b988086512d76fe9e8f846 (diff) | |
mm: remove unlikely() from page_mapping()
page_mapping() has a unlikely that the mapping has PAGE_MAPPING_ANON set.
But running the annotated branch profiler on a normal desktop system doing
vairous tasks (xchat, evolution, firefox, distcc), it is not really that
unlikely that the mapping here will have the PAGE_MAPPING_ANON flag set:
correct incorrect % Function File Line
------- --------- - -------- ---- ----
35935762 1270265395 97 page_mapping mm.h 659
1306198001 143659 0 page_mapping mm.h 657
203131478 121586 0 page_mapping mm.h 657
5415491 1116 0 page_mapping mm.h 657
74899487 1116 0 page_mapping mm.h 657
203132845 224 0 page_mapping mm.h 659
5415464 27 0 page_mapping mm.h 659
13552 0 0 page_mapping mm.h 657
13552 0 0 page_mapping mm.h 659
242630 0 0 page_mapping mm.h 657
242630 0 0 page_mapping mm.h 659
74899487 0 0 page_mapping mm.h 659
The page_mapping() is a static inline, which is why it shows up multiple
times.
The unlikely in page_mapping() was correct a total of 1909540379 times and
incorrect 1270533123 times, with a 39% being incorrect. With this much of
an error, it's best to simply remove the unlikely and have the compiler
and branch prediction figure this out.
Signed-off-by: Steven Rostedt <[email protected]>
Cc: KOSAKI Motohiro <[email protected]>
Cc: Nick Piggin <[email protected]>
Cc: Rik van Riel <[email protected]>
Cc: Lee Schermerhorn <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Diffstat (limited to 'kernel/trace/trace_workqueue.c')
0 files changed, 0 insertions, 0 deletions