I found that page-types is very slow and my testing shows many timeout errors. Here's an example with a simple program allocating 1000 thps.
$ time ./page-types -p $(pgrep -f test_alloc) ... real 0m17.201s user 0m16.889s sys 0m0.312s $ time ./page-types.patched -p $(pgrep -f test_alloc) ... real 0m0.182s user 0m0.046s sys 0m0.135s Most of time is spent in memset(), which isn't necessary because we check that the return of kpagecgroup_read() is equal to pages and uninitialized memory is never used. So we can drop this memset(). Fixes: 954e95584579 ("tools/vm/page-types.c: add memory cgroup dumping and filtering") Signed-off-by: Naoya Horiguchi <n-horigu...@ah.jp.nec.com> --- tools/vm/page-types.c | 2 -- 1 file changed, 2 deletions(-) diff --git v4.5-rc5-mmotm-2016-02-24-16-18/tools/vm/page-types.c v4.5-rc5-mmotm-2016-02-24-16-18_patched/tools/vm/page-types.c index dab61c3..c192baf 100644 --- v4.5-rc5-mmotm-2016-02-24-16-18/tools/vm/page-types.c +++ v4.5-rc5-mmotm-2016-02-24-16-18_patched/tools/vm/page-types.c @@ -633,8 +633,6 @@ static void walk_pfn(unsigned long voffset, unsigned long pages; unsigned long i; - memset(cgi, 0, sizeof cgi); - while (count) { batch = min_t(unsigned long, count, KPAGEFLAGS_BATCH); pages = kpageflags_read(buf, index, batch); -- 2.7.0