From 1c222bce7dd0cb9578b4c5cd3874a74f1db497c3 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Thu, 6 Aug 2009 20:57:41 +0200 Subject: perf tools: Fix multi-counter stat bug caused by incorrect reading of perf.data file header Brice Goglin reported that only the first result from a multi-counter perf record --stat run is accurate, the rest looks bogus. A silly mistake made us re-read the first attribute for every recorded attribute. Reported-by: Brice Goglin Signed-off-by: Peter Zijlstra Tested-by: Brice Goglin Cc: paulus@samba.org Signed-off-by: Ingo Molnar --- tools/perf/util/header.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'tools/perf/util/header.c') diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c index 450384b3bbe..95a44bcfc2d 100644 --- a/tools/perf/util/header.c +++ b/tools/perf/util/header.c @@ -213,9 +213,10 @@ struct perf_header *perf_header__read(int fd) for (i = 0; i < nr_attrs; i++) { struct perf_header_attr *attr; - off_t tmp = lseek(fd, 0, SEEK_CUR); + off_t tmp; do_read(fd, &f_attr, sizeof(f_attr)); + tmp = lseek(fd, 0, SEEK_CUR); attr = perf_header_attr__new(&f_attr.attr); -- cgit v1.2.3 From 7eac7e9e726c1b136bd7e0ad6671ce315f48bb18 Mon Sep 17 00:00:00 2001 From: Pierre Habouzit Date: Fri, 7 Aug 2009 14:16:00 +0200 Subject: perf util: Fix do_read() to fail on EOF instead of busy-looping While toying with perf, I've noticed that perf record can easily enter a busy loop when doing something as silly as: $ perf record -A ls Yeah, do_read here really wants to read a known size, not being able to should die(), not busy-loop ;) That was the cause for the bug. Signed-off-by: Pierre Habouzit Acked-by: Peter Zijlstra Cc: Paul Mackerras Signed-off-by: Ingo Molnar --- tools/perf/util/header.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'tools/perf/util/header.c') diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c index 95a44bcfc2d..b92a457ca32 100644 --- a/tools/perf/util/header.c +++ b/tools/perf/util/header.c @@ -185,6 +185,8 @@ static void do_read(int fd, void *buf, size_t size) if (ret < 0) die("failed to read"); + if (ret == 0) + die("failed to read: missing data"); size -= ret; buf += ret; -- cgit v1.2.3