Currently perf requires the -m / --mmap_pages option to be a power of 2.
To be more user friendly perf should automatically round this up to the
next power of 2.
Currently:
$ perf record -m 3 -a -- sleep 1
--mmap_pages/-m value must be a power of two.sleep: Terminated
With patch:
$ perf record -m 3 -a -- sleep 1
rounding mmap pages size to 16384 (4 pages)
...
Signed-off-by: David Ahern <dsah...@gmail.com>
Suggested-by: Ingo Molnar <mi...@kernel.org>
Cc: Ingo Molnar <mi...@kernel.org>
Cc: Jiri Olsa <jo...@redhat.com>
---
tools/perf/util/evlist.c | 11 ++++++-----
1 file changed, 6 insertions(+), 5 deletions(-)
diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index b939221efd8d..9ec3a5a45f22 100644
--- a/tools/perf/util/evlist.c
+++ b/tools/perf/util/evlist.c
@@ -722,11 +722,6 @@ int perf_evlist__parse_mmap_pages(const struct option
*opt, const char *str,
if (val != (unsigned long) -1) {
/* we got file size value */
pages = PERF_ALIGN(val, page_size) / page_size;
- if (pages < (1UL << 31) && !is_power_of_2(pages)) {
- pages = next_pow2(pages);
- pr_info("rounding mmap pages size to %lu (%lu pages)\n",
- pages * page_size, pages);
- }
} else {
/* we got pages count value */
char *eptr;
@@ -737,6 +732,12 @@ int perf_evlist__parse_mmap_pages(const struct option
*opt, const char *str,
}
}
+ if (pages < (1UL << 31) && !is_power_of_2(pages)) {
+ pages = next_pow2(pages);
+ pr_info("rounding mmap pages size to %lu (%lu pages)\n",
+ pages * page_size, pages);
+ }
+
if (pages > UINT_MAX || pages > SIZE_MAX / page_size) {
pr_err("--mmap_pages/-m value too big\n");
return -1;
--
1.8.3.4 (Apple Git-47)
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