From: Mike Galbraith Date: Tue, 13 Oct 2009 12:57:20 +0000 (+0200) Subject: perf tools: Remove expensive old debug code from perf top X-Git-Tag: v2.6.33-rc1~48^2~310^2~45 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=f4f0b418188cc7995375acbb54e87c80f21861bd;p=platform%2Fupstream%2Fkernel-adaptation-pc.git 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 Signed-off-by: Mike Galbraith Cc: Peter Zijlstra Cc: Peter Zijlstra LKML-Reference: <1255438640.7173.1.camel@marge.simson.net> Signed-off-by: Ingo Molnar --- 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 @@ static unsigned int mmap_read_head(struct mmap_data *md) 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 @@ static void mmap_read_counter(struct mmap_data *md) 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 @@ static void mmap_read_counter(struct mmap_data *md) */ 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 @@ static void mmap_read_counter(struct mmap_data *md) old = head; } - last_read = this_read; - for (; old != head;) { event_t *event = (event_t *)&data[old & md->mask];