From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753458AbbJIGHc (ORCPT ); Fri, 9 Oct 2015 02:07:32 -0400 Received: from mail-wi0-f182.google.com ([209.85.212.182]:34992 "EHLO mail-wi0-f182.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753133AbbJIGHa (ORCPT ); Fri, 9 Oct 2015 02:07:30 -0400 Date: Fri, 9 Oct 2015 15:03:33 +0900 From: Namhyung Kim To: Jiri Olsa Cc: Arnaldo Carvalho de Melo , Ingo Molnar , Peter Zijlstra , LKML , Frederic Weisbecker , Stephane Eranian , David Ahern , Andi Kleen , Adrian Hunter Subject: Re: [RFC/PATCH 02/38] perf tools: Save mmap_param.len instead of mask Message-ID: <20151009060333.GA1171@danjae.orange-hotspot.com> References: <1443763159-29098-1-git-send-email-namhyung@kernel.org> <1443763159-29098-3-git-send-email-namhyung@kernel.org> <20151008101711.GD17581@krava.landal.opennet> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20151008101711.GD17581@krava.landal.opennet> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Jiri, On Thu, Oct 08, 2015 at 12:17:11PM +0200, Jiri Olsa wrote: > On Fri, Oct 02, 2015 at 02:18:43PM +0900, Namhyung Kim wrote: > > It is more convenient saving mmap length rather than (bit) mask. With > > this patch, we can eliminate dependency to perf_evlist other than > > getting mmap_desc for dealing with mmaps. The mask and length can be > > converted using perf_evlist__mmap_mask/len(). > > > > Cc: Jiri Olsa > > Cc: Adrian Hunter > > Signed-off-by: Namhyung Kim > > after this patch I'm hitting: > > [jolsa@krava perf]$ ./perf record kill > kill: not enough arguments > perf: util/evlist.c:1003: perf_evlist__mmap_len: Assertion `!((mask & page_size) != 0)' failed. > Aborted (core dumped) > [jolsa@krava perf]$ This is strange.. I think I fixed it already. And the expression in the assertion is different than the code in the patch: static size_t perf_evlist__mmap_len(size_t mask) { BUG_ON(((mask + 1) % page_size) != 0); return mask + 1 + page_size; } Could you please double check? Thanks, Namhyung > > > jirka > > > --- > > tools/perf/util/evlist.c | 31 +++++++++++++++++++++++++------ > > 1 file changed, 25 insertions(+), 6 deletions(-) > > > > diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c > > index c5180a29db1b..e46adcd5b408 100644 > > --- a/tools/perf/util/evlist.c > > +++ b/tools/perf/util/evlist.c > > @@ -29,6 +29,8 @@ > > > > static void perf_evlist__mmap_put(struct perf_evlist *evlist, int idx); > > static void __perf_evlist__munmap(struct perf_evlist *evlist, int idx); > > +static size_t perf_evlist__mmap_mask(size_t len); > > +static size_t perf_evlist__mmap_len(size_t mask); > > > > #define FD(e, x, y) (*(int *)xyarray__entry(e->fd, x, y)) > > #define SID(e, x, y) xyarray__entry(e->sample_id, x, y) > > @@ -871,7 +873,9 @@ void __weak auxtrace_mmap_params__set_idx( > > static void __perf_evlist__munmap(struct perf_evlist *evlist, int idx) > > { > > if (evlist->mmap[idx].base != NULL) { > > - munmap(evlist->mmap[idx].base, evlist->mmap_len); > > + size_t mmap_len = perf_evlist__mmap_len(evlist->mmap[idx].mask); > > + > > + munmap(evlist->mmap[idx].base, mmap_len); > > evlist->mmap[idx].base = NULL; > > atomic_set(&evlist->mmap[idx].refcnt, 0); > > } > > @@ -901,8 +905,8 @@ static int perf_evlist__alloc_mmap(struct perf_evlist *evlist) > > } > > > > struct mmap_params { > > - int prot; > > - int mask; > > + int prot; > > + size_t len; > > struct auxtrace_mmap_params auxtrace_mp; > > }; > > > > @@ -924,8 +928,8 @@ static int __perf_evlist__mmap(struct perf_evlist *evlist, int idx, > > */ > > atomic_set(&evlist->mmap[idx].refcnt, 2); > > evlist->mmap[idx].prev = 0; > > - evlist->mmap[idx].mask = mp->mask; > > - evlist->mmap[idx].base = mmap(NULL, evlist->mmap_len, mp->prot, > > + evlist->mmap[idx].mask = perf_evlist__mmap_mask(mp->len); > > + evlist->mmap[idx].base = mmap(NULL, mp->len, mp->prot, > > MAP_SHARED, fd, 0); > > if (evlist->mmap[idx].base == MAP_FAILED) { > > pr_debug2("failed to mmap perf event ring buffer, error %d\n", > > @@ -1071,6 +1075,21 @@ static size_t perf_evlist__mmap_size(unsigned long pages) > > return (pages + 1) * page_size; > > } > > > > +static size_t perf_evlist__mmap_mask(size_t len) > > +{ > > + BUG_ON(len <= page_size); > > + BUG_ON((len % page_size) != 0); > > + > > + return len - page_size - 1; > > +} > > + > > +static size_t perf_evlist__mmap_len(size_t mask) > > +{ > > + BUG_ON(((mask + 1) % page_size) != 0); > > + > > + return mask + 1 + page_size; > > +} > > + > > static long parse_pages_arg(const char *str, unsigned long min, > > unsigned long max) > > { > > @@ -1176,7 +1195,7 @@ int perf_evlist__mmap_ex(struct perf_evlist *evlist, unsigned int pages, > > evlist->overwrite = overwrite; > > evlist->mmap_len = perf_evlist__mmap_size(pages); > > pr_debug("mmap size %zuB\n", evlist->mmap_len); > > - mp.mask = evlist->mmap_len - page_size - 1; > > + mp.len = evlist->mmap_len; > > > > auxtrace_mmap_params__init(&mp.auxtrace_mp, evlist->mmap_len, > > auxtrace_pages, auxtrace_overwrite); > > -- > > 2.6.0 > >