From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932810AbZJFTWH (ORCPT ); Tue, 6 Oct 2009 15:22:07 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932403AbZJFTWH (ORCPT ); Tue, 6 Oct 2009 15:22:07 -0400 Received: from mail-ew0-f217.google.com ([209.85.219.217]:55422 "EHLO mail-ew0-f217.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932317AbZJFTWF (ORCPT ); Tue, 6 Oct 2009 15:22:05 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=from:to:cc:subject:date:message-id:x-mailer:in-reply-to:references; b=yDdWNviNik6INC48EvPqWvwKCz/Zce0cRNM1u3c47mdcRJzV2S3AL8HG2hH1prDaYV 6letwWuuWkvfyv42xM+4S4P11ad4FGeuKkUJF5tzN72lEoR4ETEb+Jh1/tZrfxO1U0vt o+UuDttXJz3hIhoe/mM+lpnll49Ijey2DJ7jA= From: Frederic Weisbecker To: Ingo Molnar Cc: LKML , Frederic Weisbecker , Peter Zijlstra , Arnaldo Carvalho de Melo , Mike Galbraith , Paul Mackerras , Tom Zanussi Subject: [PATCH v2] perf tools: Start the perf.data mapping at data offset in perf trace Date: Tue, 6 Oct 2009 21:21:26 +0200 Message-Id: <1254856886-10348-1-git-send-email-fweisbec@gmail.com> X-Mailer: git-send-email 1.6.2.3 In-Reply-To: <1254856626-10286-1-git-send-email-fweisbec@gmail.com> References: <1254856626-10286-1-git-send-email-fweisbec@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Currently, we are mapping perf.data in the beginning of the file and use the data offset as a buffer offset. This may exceed the mapping area if the data offset is upper than page_size * mmap_window and result in a page fault (thing that happen if we merge trace.info in perf.data). Instead, let's start the mapping in the page that matches our data offset. v2: Drop a junk from another patch (trace_report() removal) Signed-off-by: Frederic Weisbecker Cc: Peter Zijlstra Cc: Arnaldo Carvalho de Melo Cc: Mike Galbraith Cc: Paul Mackerras Cc: Tom Zanussi --- tools/perf/builtin-trace.c | 7 ++++++- 1 files changed, 6 insertions(+), 1 deletions(-) diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c index 5d4c84d..d573d4e 100644 --- a/tools/perf/builtin-trace.c +++ b/tools/perf/builtin-trace.c @@ -143,6 +143,7 @@ static int __cmd_trace(void) int ret, rc = EXIT_FAILURE; unsigned long offset = 0; unsigned long head = 0; + unsigned long shift; struct stat perf_stat; event_t *event; uint32_t size; @@ -180,6 +181,10 @@ static int __cmd_trace(void) return EXIT_FAILURE; } + shift = page_size * (head / page_size); + offset += shift; + head -= shift; + remap: buf = (char *)mmap(NULL, page_size * mmap_window, PROT_READ, MAP_SHARED, input, offset); @@ -192,9 +197,9 @@ more: event = (event_t *)(buf + head); if (head + event->header.size >= page_size * mmap_window) { - unsigned long shift = page_size * (head / page_size); int res; + shift = page_size * (head / page_size); res = munmap(buf, page_size * mmap_window); assert(res == 0); -- 1.6.2.3