Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751401AbeAOU0U (ORCPT + 1 other); Mon, 15 Jan 2018 15:26:20 -0500 Received: from mga04.intel.com ([192.55.52.120]:59564 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751017AbeAOUVu (ORCPT ); Mon, 15 Jan 2018 15:21:50 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.46,365,1511856000"; d="scan'208";a="22473487" From: kan.liang@intel.com To: acme@kernel.org, peterz@infradead.org, mingo@redhat.com, linux-kernel@vger.kernel.org Cc: wangnan0@huawei.com, jolsa@kernel.org, namhyung@kernel.org, ak@linux.intel.com, yao.jin@linux.intel.com, Kan Liang Subject: [PATCH V4 05/15] perf mmap: introduce perf_mmap__read_done Date: Mon, 15 Jan 2018 12:20:41 -0800 Message-Id: <1516047651-164336-6-git-send-email-kan.liang@intel.com> X-Mailer: git-send-email 2.5.5 In-Reply-To: <1516047651-164336-1-git-send-email-kan.liang@intel.com> References: <1516047651-164336-1-git-send-email-kan.liang@intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Return-Path: From: Kan Liang The direction of overwrite mode is backward. The last perf_mmap__read() will set tail to map->prev. Need to correct the map->prev to head which is the end of next read. It will be used later. Signed-off-by: Kan Liang --- tools/perf/util/mmap.c | 11 +++++++++++ tools/perf/util/mmap.h | 1 + 2 files changed, 12 insertions(+) diff --git a/tools/perf/util/mmap.c b/tools/perf/util/mmap.c index 2f2cc3a..2291160 100644 --- a/tools/perf/util/mmap.c +++ b/tools/perf/util/mmap.c @@ -342,3 +342,14 @@ int perf_mmap__push(struct perf_mmap *md, bool overwrite, out: return rc; } + +/* + * Mandatory for overwrite mode + * The direction of overwrite mode is backward. + * The last perf_mmap__read() will set tail to map->prev. + * Need to correct the map->prev to head which is the end of next read. + */ +void perf_mmap__read_done(struct perf_mmap *map) +{ + map->prev = perf_mmap__read_head(map); +} diff --git a/tools/perf/util/mmap.h b/tools/perf/util/mmap.h index 0633308..4434cc5 100644 --- a/tools/perf/util/mmap.h +++ b/tools/perf/util/mmap.h @@ -96,4 +96,5 @@ size_t perf_mmap__mmap_len(struct perf_mmap *map); int perf_mmap__read_init(struct perf_mmap *map, bool overwrite, u64 *startp, u64 *endp); +void perf_mmap__read_done(struct perf_mmap *map); #endif /*__PERF_MMAP_H */ -- 2.5.5