On 08/11/13 06:36, David Ahern wrote: > 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) > ...
This prevents: --out-pages=0 from working e.g. tools/perf/perf record -vv --out-pages=0 uname rounding mmap pages size to 4096 (1 pages) Although without this patch: tools/perf/perf record -vv --out-pages=0 uname --mmap_pages/-m value must be a power of two. usage: perf record [<options>] [<command>] or: perf record [<options>] -- <command> [<options>] --out-pages <pages> Number of pages or size with units to use for output (default 64M) Also there is: tools/perf/perf record -vv --no-out-pages uname Segmentation fault (core dumped) > 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; -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/