lkml.org 
[lkml]   [2009]   [Mar]   [28]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[PATCH 3/9] 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>
---
Documentation/perf_counter/kerneltop.c | 14 +-------------
1 file changed, 1 insertion(+), 13 deletions(-)
Index: linux-2.6/Documentation/perf_counter/kerneltop.c
===================================================================
--- linux-2.6.orig/Documentation/perf_counter/kerneltop.c
+++ linux-2.6/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;
}
--



\
 
 \ /
  Last update: 2009-03-28 20:53    [from the cache]
©2003-2011 Jasper Spaans