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=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS 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 50D82C433DF for ; Wed, 8 Jul 2020 20:30:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 372A82078A for ; Wed, 8 Jul 2020 20:30:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725915AbgGHUaU (ORCPT ); Wed, 8 Jul 2020 16:30:20 -0400 Received: from mail.kernel.org ([198.145.29.99]:38790 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726044AbgGHUaT (ORCPT ); Wed, 8 Jul 2020 16:30:19 -0400 Received: from gandalf.local.home (cpe-66-24-58-225.stny.res.rr.com [66.24.58.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 6B55620775; Wed, 8 Jul 2020 20:30:18 +0000 (UTC) Received: from rostedt by gandalf.local.home with local (Exim 4.93) (envelope-from ) id 1jtGht-004NNa-4v; Wed, 08 Jul 2020 16:30:17 -0400 Message-ID: <20200708203017.038156451@goodmis.org> User-Agent: quilt/0.66 Date: Wed, 08 Jul 2020 16:28:52 -0400 From: Steven Rostedt To: linux-trace-devel@vger.kernel.org Cc: "Tzvetomir Stoyanov (VMware)" Subject: [PATCH 2/5] tools lib traceveent: Fix kbuffer_start_of_data() to return the first record References: <20200708202850.764168067@goodmis.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-trace-devel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-trace-devel@vger.kernel.org From: "Tzvetomir Stoyanov (VMware)" The first record in a ring buffer page may not allways be at the beginning of the page. There could be time-extends injected before it. In this case kbuffer_start_of_data() will not return the first record, as expected. Additional field "start" is added in kbuffer struct, to hold the offset of the first record from the page and kbuffer_start_of_data() is modified to use it. Link: https://lore.kernel.org/linux-trace-devel/20200706154714.27566-1-tz.stoyanov@gmail.com Signed-off-by: Steven Rostedt (VMware) [ Finished the patch from Steven ] Signed-off-by: Tzvetomir Stoyanov (VMware) --- lib/traceevent/kbuffer-parse.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/lib/traceevent/kbuffer-parse.c b/lib/traceevent/kbuffer-parse.c index 2c5f00a9e786..844db976b38c 100644 --- a/lib/traceevent/kbuffer-parse.c +++ b/lib/traceevent/kbuffer-parse.c @@ -35,6 +35,7 @@ enum { * @next - offset from @data to the start of next event * @size - The size of data on @data * @start - The offset from @subbuffer where @data lives + * @first - The offset from @subbuffer where the first non time stamp event lives * * @read_4 - Function to read 4 raw bytes (may swap) * @read_8 - Function to read 8 raw bytes (may swap) @@ -51,6 +52,7 @@ struct kbuffer { unsigned int next; unsigned int size; unsigned int start; + unsigned int first; unsigned int (*read_4)(void *ptr); unsigned long long (*read_8)(void *ptr); @@ -546,6 +548,9 @@ int kbuffer_load_subbuffer(struct kbuffer *kbuf, void *subbuffer) next_event(kbuf); + /* save the first record from the page */ + kbuf->first = kbuf->curr; + return 0; } @@ -755,7 +760,7 @@ void kbuffer_set_old_format(struct kbuffer *kbuf) */ int kbuffer_start_of_data(struct kbuffer *kbuf) { - return kbuf->start; + return kbuf->first + kbuf->start; } /** -- 2.26.2