From patchwork Tue Apr 26 02:28:55 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wang Nan X-Patchwork-Id: 66655 Delivered-To: patch@linaro.org Received: by 10.140.93.198 with SMTP id d64csp1362226qge; Mon, 25 Apr 2016 19:31:25 -0700 (PDT) X-Received: by 10.98.3.133 with SMTP id 127mr94057pfd.93.1461637885369; Mon, 25 Apr 2016 19:31:25 -0700 (PDT) Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id yx4si1112014pac.109.2016.04.25.19.31.25; Mon, 25 Apr 2016 19:31:25 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751968AbcDZCbV (ORCPT + 29 others); Mon, 25 Apr 2016 22:31:21 -0400 Received: from szxga02-in.huawei.com ([119.145.14.65]:38669 "EHLO szxga02-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750843AbcDZCbT (ORCPT ); Mon, 25 Apr 2016 22:31:19 -0400 Received: from 172.24.1.47 (EHLO SZXEML424-HUB.china.huawei.com) ([172.24.1.47]) by szxrg02-dlp.huawei.com (MOS 4.3.7-GA FastPath queued) with ESMTP id DFZ10575; Tue, 26 Apr 2016 10:29:39 +0800 (CST) Received: from linux-4hy3.site (10.107.193.248) by SZXEML424-HUB.china.huawei.com (10.82.67.153) with Microsoft SMTP Server id 14.3.235.1; Tue, 26 Apr 2016 10:29:03 +0800 From: Wang Nan To: CC: , Wang Nan , "Arnaldo Carvalho de Melo" , Peter Zijlstra , Zefan Li , Subject: [PATCH 2/5] perf tools: Extract __perf_evlist__mmap_read() Date: Tue, 26 Apr 2016 02:28:55 +0000 Message-ID: <1461637738-62722-3-git-send-email-wangnan0@huawei.com> X-Mailer: git-send-email 1.8.3.4 In-Reply-To: <1461637738-62722-1-git-send-email-wangnan0@huawei.com> References: <1461637738-62722-1-git-send-email-wangnan0@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.107.193.248] X-CFilter-Loop: Reflected X-Mirapoint-Virus-RAPID-Raw: score=unknown(0), refid=str=0001.0A020203.571ED295.005F, 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: 7c3c107c7d2672bbfc23843b24fd13b7 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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(-) -- 1.8.3.4 diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c index 85271e5..3ee94b2 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;