From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=0.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,UNWANTED_LANGUAGE_BODY,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7AABBC433F5 for ; Mon, 27 Aug 2018 08:33:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2C5D2208CA for ; Mon, 27 Aug 2018 08:33:08 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2C5D2208CA Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726971AbeH0MSp (ORCPT ); Mon, 27 Aug 2018 08:18:45 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:50142 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726802AbeH0MSp (ORCPT ); Mon, 27 Aug 2018 08:18:45 -0400 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 4065287916; Mon, 27 Aug 2018 08:33:05 +0000 (UTC) Received: from krava (unknown [10.43.17.209]) by smtp.corp.redhat.com (Postfix) with SMTP id D0F557291F; Mon, 27 Aug 2018 08:33:03 +0000 (UTC) Date: Mon, 27 Aug 2018 10:33:03 +0200 From: Jiri Olsa To: Alexey Budankov Cc: Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Alexander Shishkin , Namhyung Kim , Andi Kleen , linux-kernel , linux-perf-users@vger.kernel.org Subject: Re: [PATCH v2 1/2]: perf util: map data buffer for preserving collected data Message-ID: <20180827083303.GD24695@krava> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) X-Scanned-By: MIMEDefang 2.79 on 10.11.54.5 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.1]); Mon, 27 Aug 2018 08:33:05 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.1]); Mon, 27 Aug 2018 08:33:05 +0000 (UTC) for IP:'10.11.54.5' DOMAIN:'int-mx05.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'jolsa@redhat.com' RCPT:'' Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Aug 23, 2018 at 07:42:09PM +0300, Alexey Budankov wrote: SNIP > diff --git a/tools/perf/util/mmap.c b/tools/perf/util/mmap.c > index fc832676a798..e71d46cb01cc 100644 > --- a/tools/perf/util/mmap.c > +++ b/tools/perf/util/mmap.c > @@ -155,6 +155,10 @@ void __weak auxtrace_mmap_params__set_idx(struct auxtrace_mmap_params *mp __mayb > > void perf_mmap__munmap(struct perf_mmap *map) > { > + if (map->data != NULL) { > + munmap(map->data, perf_mmap__mmap_len(map)); > + map->data = NULL; > + } > if (map->base != NULL) { > munmap(map->base, perf_mmap__mmap_len(map)); > map->base = NULL; > @@ -190,6 +194,14 @@ int perf_mmap__mmap(struct perf_mmap *map, struct mmap_params *mp, int fd) > map->base = NULL; > return -1; > } > + map->data = mmap(NULL, perf_mmap__mmap_len(map), PROT_READ | PROT_WRITE, > + MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); hum, why does map->data need to be mmap-ed? jirka