From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756584AbcAYKLL (ORCPT ); Mon, 25 Jan 2016 05:11:11 -0500 Received: from szxga01-in.huawei.com ([58.251.152.64]:38458 "EHLO szxga01-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756491AbcAYJ6b (ORCPT ); Mon, 25 Jan 2016 04:58:31 -0500 From: Wang Nan To: Alexei Starovoitov , Arnaldo Carvalho de Melo CC: Brendan Gregg , Daniel Borkmann , "David S. Miller" , He Kuang , Jiri Olsa , Li Zefan , Masami Hiramatsu , Namhyung Kim , Peter Zijlstra , , Will Deacon , , Wang Nan Subject: [PATCH 46/54] perf record: Don't poll on overwrite channel Date: Mon, 25 Jan 2016 09:56:33 +0000 Message-ID: <1453715801-7732-47-git-send-email-wangnan0@huawei.com> X-Mailer: git-send-email 1.8.3.4 In-Reply-To: <1453715801-7732-1-git-send-email-wangnan0@huawei.com> References: <1453715801-7732-1-git-send-email-wangnan0@huawei.com> MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.107.193.248] X-CFilter-Loop: Reflected X-Mirapoint-Virus-RAPID-Raw: score=unknown(0), refid=str=0001.0A020206.56A5F1A6.00E0,ss=1,re=0.000,recu=0.000,reip=0.000,cl=1,cld=1,fgs=0, ip=0.0.0.0, so=2013-06-18 04:22:30, dmn=2013-03-21 17:37:32 X-Mirapoint-Loop-Id: c75d2223e5bdc7fa0ad5225270270888 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org There's no need to receive events from overwrite ring buffer. Instead, perf should make them run background until something happen. This patch makes events from overwrite ring buffer is ignored except POLLERR and POLLHUP. Signed-off-by: Wang Nan Signed-off-by: He Kuang Cc: Arnaldo Carvalho de Melo Cc: Jiri Olsa Cc: Masami Hiramatsu Cc: Namhyung Kim Cc: Zefan Li Cc: pi3orama@163.com --- tools/perf/util/evlist.c | 23 +++++++++++++++++++---- 1 file changed, 19 insertions(+), 4 deletions(-) diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c index d728d82..3c308a7 100644 --- a/tools/perf/util/evlist.c +++ b/tools/perf/util/evlist.c @@ -461,9 +461,9 @@ int perf_evlist__alloc_pollfd(struct perf_evlist *evlist) return 0; } -static int __perf_evlist__add_pollfd(struct perf_evlist *evlist, int fd, int idx) +static int __perf_evlist__add_pollfd(struct perf_evlist *evlist, int fd, int idx, short revent) { - int pos = fdarray__add(&evlist->pollfd, fd, POLLIN | POLLERR | POLLHUP); + int pos = fdarray__add(&evlist->pollfd, fd, revent | POLLERR | POLLHUP); /* * Save the idx so that when we filter out fds POLLHUP'ed we can * close the associated evlist->mmap[] entry. @@ -479,7 +479,7 @@ static int __perf_evlist__add_pollfd(struct perf_evlist *evlist, int fd, int idx int perf_evlist__add_pollfd(struct perf_evlist *evlist, int fd) { - return __perf_evlist__add_pollfd(evlist, fd, -1); + return __perf_evlist__add_pollfd(evlist, fd, -1, POLLIN); } static void perf_evlist__munmap_filtered(struct fdarray *fda, int fd) @@ -1007,6 +1007,18 @@ perf_evlist__channel_complete(struct perf_evlist *evlist) return 0; } +static bool +perf_evlist__should_poll(struct perf_evlist *evlist, + struct perf_evsel *evsel, + int channel) +{ + if (evsel->system_wide) + return false; + if (perf_evlist__channel_check(evlist, channel, RDONLY)) + return false; + return true; +} + static int perf_evlist__mmap_per_evsel(struct perf_evlist *evlist, int _idx, struct mmap_params *mp, int cpu, int thread, int *outputs) @@ -1015,6 +1027,7 @@ static int perf_evlist__mmap_per_evsel(struct perf_evlist *evlist, int _idx, evlist__for_each(evlist, evsel) { int fd, channel, idx, err; + short revent = POLLIN; channel = perf_evlist__channel_find(evlist, evsel, false); if (channel < 0) { @@ -1044,6 +1057,8 @@ static int perf_evlist__mmap_per_evsel(struct perf_evlist *evlist, int _idx, perf_evlist__mmap_get(evlist, idx); } + if (!perf_evlist__should_poll(evlist, evsel, channel)) + revent = 0; /* * The system_wide flag causes a selected event to be opened * always without a pid. Consequently it will never get a @@ -1052,7 +1067,7 @@ static int perf_evlist__mmap_per_evsel(struct perf_evlist *evlist, int _idx, * Therefore don't add it for polling. */ if (!evsel->system_wide && - __perf_evlist__add_pollfd(evlist, fd, idx) < 0) { + __perf_evlist__add_pollfd(evlist, fd, idx, revent) < 0) { perf_evlist__mmap_put(evlist, idx); return -1; } -- 1.8.3.4