perf tools: Remove expensive old debug code from perf top
Calling gettimeofday() at high frequency is painful for handicapped
boxen. The spot calling gettimeofday() is old unneeded debug code,
so remove it.
Reported-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1255438640.7173.1.camel@marge.simson.net>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c
index c0f69e8..2d8806b 100644
--- a/tools/perf/builtin-top.c
+++ b/tools/perf/builtin-top.c
@@ -870,8 +870,6 @@
return head;
}
-struct timeval last_read, this_read;
-
static void mmap_read_counter(struct mmap_data *md)
{
unsigned int head = mmap_read_head(md);
@@ -879,8 +877,6 @@
unsigned char *data = md->base + page_size;
int diff;
- gettimeofday(&this_read, NULL);
-
/*
* If we're further behind than half the buffer, there's a chance
* the writer will bite our tail and mess up the samples under us.
@@ -891,14 +887,7 @@
*/
diff = head - old;
if (diff > md->mask / 2 || diff < 0) {
- struct timeval iv;
- unsigned long msecs;
-
- timersub(&this_read, &last_read, &iv);
- msecs = iv.tv_sec*1000 + iv.tv_usec/1000;
-
- fprintf(stderr, "WARNING: failed to keep up with mmap data."
- " Last read %lu msecs ago.\n", msecs);
+ fprintf(stderr, "WARNING: failed to keep up with mmap data.\n");
/*
* head points to a known good entry, start there.
@@ -906,8 +895,6 @@
old = head;
}
- last_read = this_read;
-
for (; old != head;) {
event_t *event = (event_t *)&data[old & md->mask];