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| author | Tom Zanussi <tzanussi@gmail.com> | 2010-05-05 08:02:10 +0400 |
|---|---|---|
| committer | Frederic Weisbecker <fweisbec@gmail.com> | 2010-05-20 10:37:17 +0400 |
| commit | cbb5cf7ff6b298beacfe23db3386335b0b9c0a2d (patch) | |
| tree | 153901937a7ce3acffc536c48652e0d87a52685b /tools/perf | |
| parent | 537b60d17894b7c19a6060feae40299d7109d6e7 (diff) | |
| download | linux-cbb5cf7ff6b298beacfe23db3386335b0b9c0a2d.tar.xz | |
perf: Use read() instead of lseek() in trace_event_read.c:skip()
This is a small fix for a problem affecting live-mode, introduced
recently:
root@tropicana:~# perf trace rwtop
perf trace started with Perl
script /root/libexec/perf-core/scripts/perl/rwtop.pl
Fatal: did not read header event
commit d00a47cce569a3e660a8c9de5d57af28d6a9f0f7 added a skip()
function to skip over e.g. header_page, but this doesn't work for
live mode. This patch re-implements skip() to use read() instead of
lseek() to fix that.
Signed-off-by: Tom Zanussi <tzanussi@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <1273032130.6383.28.camel@tropicana>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Diffstat (limited to 'tools/perf')
| -rw-r--r-- | tools/perf/util/trace-event-read.c | 19 |
1 files changed, 13 insertions, 6 deletions
diff --git a/tools/perf/util/trace-event-read.c b/tools/perf/util/trace-event-read.c index cb54cd002f49..f55cc3a765a1 100644 --- a/tools/perf/util/trace-event-read.c +++ b/tools/perf/util/trace-event-read.c @@ -53,12 +53,6 @@ static unsigned long page_size; static ssize_t calc_data_size; static bool repipe; -/* If it fails, the next read will report it */ -static void skip(int size) -{ - lseek(input_fd, size, SEEK_CUR); -} - static int do_read(int fd, void *buf, int size) { int rsize = size; @@ -98,6 +92,19 @@ static int read_or_die(void *data, int size) return r; } +/* If it fails, the next read will report it */ +static void skip(int size) +{ + char buf[BUFSIZ]; + int r; + + while (size) { + r = size > BUFSIZ ? BUFSIZ : size; + read_or_die(buf, r); + size -= r; + }; +} + static unsigned int read4(void) { unsigned int data; |