Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932092AbcDGJnY (ORCPT ); Thu, 7 Apr 2016 05:43:24 -0400 Received: from szxga02-in.huawei.com ([119.145.14.65]:6000 "EHLO szxga02-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755499AbcDGJnT (ORCPT ); Thu, 7 Apr 2016 05:43:19 -0400 From: Wang Nan To: , CC: , , , Subject: [PATCH 2/4] perf tools: Extract __perf_evlist__mmap_read() Date: Thu, 7 Apr 2016 09:42:58 +0000 Message-ID: <1460022180-61262-3-git-send-email-wangnan0@huawei.com> X-Mailer: git-send-email 1.8.3.4 In-Reply-To: <1460022180-61262-1-git-send-email-wangnan0@huawei.com> References: <1460022180-61262-1-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=0001.0A090202.57062BB4.0047,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: d5d49f4c006a6c035d944a2a9fc568e1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2243 Lines: 80 Extract event reader to __perf_evlist__mmap_read(). Future commit will feed it with manually computed 'head' and 'old' pointers. Signed-off-by: Wang Nan Cc: Arnaldo Carvalho de Melo Cc: Peter Zijlstra Cc: Zefan Li Cc: pi3orama@163.com --- tools/perf/util/evlist.c | 40 +++++++++++++++++++++++++--------------- 1 file changed, 25 insertions(+), 15 deletions(-) diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c index 692fd05..119bf27 100644 --- a/tools/perf/util/evlist.c +++ b/tools/perf/util/evlist.c @@ -679,24 +679,15 @@ static struct perf_evsel *perf_evlist__event2evsel(struct perf_evlist *evlist, return NULL; } -union perf_event *perf_evlist__mmap_read(struct perf_evlist *evlist, int idx) +static union perf_event * +__perf_evlist__mmap_read(struct perf_mmap *md, bool overwrite, u64 head, + u64 old, u64 *prev) { - struct perf_mmap *md = &evlist->mmap[idx]; - u64 head; - u64 old = md->prev; - int diff; unsigned char *data = md->base + page_size; union perf_event *event = NULL; + int diff = head - old; - /* - * Check if event was unmapped due to a POLLHUP/POLLERR. - */ - if (!atomic_read(&md->refcnt)) - return NULL; - - head = perf_mmap__read_head(md); - diff = head - old; - if (evlist->overwrite) { + if (overwrite) { /* * If we're further behind than half the buffer, there's a chance * the writer will bite our tail and mess up the samples under us. @@ -751,11 +742,30 @@ union perf_event *perf_evlist__mmap_read(struct perf_evlist *evlist, int idx) } broken_event: - md->prev = old; + if (prev) + *prev = old; return event; } +union perf_event *perf_evlist__mmap_read(struct perf_evlist *evlist, int idx) +{ + struct perf_mmap *md = &evlist->mmap[idx]; + u64 head; + u64 old = md->prev; + + /* + * Check if event was unmapped due to a POLLHUP/POLLERR. + */ + if (!atomic_read(&md->refcnt)) + return NULL; + + head = perf_mmap__read_head(md); + + return __perf_evlist__mmap_read(md, evlist->overwrite, head, + old, &md->prev); +} + static bool perf_mmap__empty(struct perf_mmap *md) { return perf_mmap__read_head(md) == md->prev && !md->auxtrace_mmap.base; -- 1.8.3.4