diff options
| author | Peter Zijlstra <a.p.zijlstra@chello.nl> | 2009-03-30 19:07:04 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-04-06 09:30:37 +0200 |
| commit | 195564390210977954fe4ef45b39cdee34f41b59 (patch) | |
| tree | 4587f60a6c5ca5f7f70b299f3ed6cc234299c089 /Documentation/perf_counter | |
| parent | 38ff667b321b00f5e6830e93fb4ab11a653a2920 (diff) | |
perf_counter: kerneltop: simplify data_head read
Now that the kernel side changed, match up again.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Paul Mackerras <paulus@samba.org>
Orig-LKML-Reference: <20090330171023.327144324@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'Documentation/perf_counter')
| -rw-r--r-- | Documentation/perf_counter/kerneltop.c | 14 |
1 files changed, 1 insertions, 13 deletions
diff --git a/Documentation/perf_counter/kerneltop.c b/Documentation/perf_counter/kerneltop.c index fda1438365d..2779c57ad4b 100644 --- a/Documentation/perf_counter/kerneltop.c +++ b/Documentation/perf_counter/kerneltop.c @@ -1125,22 +1125,10 @@ struct mmap_data { static unsigned int mmap_read_head(struct mmap_data *md) { struct perf_counter_mmap_page *pc = md->base; - unsigned int seq, head; - -repeat: - rmb(); - seq = pc->lock; - - if (unlikely(seq & 1)) { - cpu_relax(); - goto repeat; - } + int head; head = pc->data_head; - rmb(); - if (pc->lock != seq) - goto repeat; return head; } |