diff options
| author | Frederic Weisbecker <fweisbec@gmail.com> | 2009-10-06 21:21:26 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-10-07 08:36:10 +0200 |
| commit | b209aa1f83964d49a332a7b6b818ebede5cdc6ef (patch) | |
| tree | 65899a686eedd374d0524a0812273bdeac5f08a3 /tools/perf/builtin-trace.c | |
| parent | 42e59d7d19dc4b49feab2a860fd9a8ca3248c833 (diff) | |
perf tools: Start the perf.data mapping at data offset in perf trace
Currently, we are mapping perf.data in the beginning of the file
and use the data offset as a buffer offset.
This may exceed the mapping area if the data offset is upper than
page_size * mmap_window and result in a page fault (thing that
happen if we merge trace.info in perf.data).
Instead, let's start the mapping in the page that matches our data
offset.
v2: Drop a junk from another patch (trace_report() removal)
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Tom Zanussi <tzanussi@gmail.com>
LKML-Reference: <1254856886-10348-1-git-send-email-fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'tools/perf/builtin-trace.c')
| -rw-r--r-- | tools/perf/builtin-trace.c | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c index 5d4c84d86373..d573d4ea6c21 100644 --- a/tools/perf/builtin-trace.c +++ b/tools/perf/builtin-trace.c @@ -143,6 +143,7 @@ static int __cmd_trace(void) int ret, rc = EXIT_FAILURE; unsigned long offset = 0; unsigned long head = 0; + unsigned long shift; struct stat perf_stat; event_t *event; uint32_t size; @@ -180,6 +181,10 @@ static int __cmd_trace(void) return EXIT_FAILURE; } + shift = page_size * (head / page_size); + offset += shift; + head -= shift; + remap: buf = (char *)mmap(NULL, page_size * mmap_window, PROT_READ, MAP_SHARED, input, offset); @@ -192,9 +197,9 @@ more: event = (event_t *)(buf + head); if (head + event->header.size >= page_size * mmap_window) { - unsigned long shift = page_size * (head / page_size); int res; + shift = page_size * (head / page_size); res = munmap(buf, page_size * mmap_window); assert(res == 0); |