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=-4.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,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 2E2B4C43381 for ; Mon, 18 Mar 2019 13:54:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EDC2520863 for ; Mon, 18 Mar 2019 13:54:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727365AbfCRNyj (ORCPT ); Mon, 18 Mar 2019 09:54:39 -0400 Received: from mail.kernel.org ([198.145.29.99]:37644 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726626AbfCRNyj (ORCPT ); Mon, 18 Mar 2019 09:54:39 -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 44D5B20857; Mon, 18 Mar 2019 13:54:38 +0000 (UTC) Date: Mon, 18 Mar 2019 09:54:36 -0400 From: Steven Rostedt To: Daniel Thompson Cc: Douglas Anderson , Ingo Molnar , Jason Wessel , kgdb-bugreport@lists.sourceforge.net, Brian Norris , linux-kernel@vger.kernel.org Subject: Re: [PATCH v4 3/3] tracing: kdb: Allow ftdump to skip all but the last few entries Message-ID: <20190318095436.7f09a371@gandalf.local.home> In-Reply-To: <20190318030238.GD27232@oak.lan> References: <20190315230906.250598-1-dianders@chromium.org> <20190315230906.250598-3-dianders@chromium.org> <20190318030238.GD27232@oak.lan> X-Mailer: Claws Mail 3.16.0 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 18 Mar 2019 03:02:38 +0000 Daniel Thompson wrote: > > diff --git a/kernel/trace/trace_kdb.c b/kernel/trace/trace_kdb.c > > index 4b666643d69f..996e1e9cd9a6 100644 > > --- a/kernel/trace/trace_kdb.c > > +++ b/kernel/trace/trace_kdb.c > > @@ -39,7 +39,8 @@ static void ftrace_dump_buf(int skip_entries, long cpu_file) > > /* don't look at user memory in panic mode */ > > tr->trace_flags &= ~TRACE_ITER_SYM_USEROBJ; > > > > - kdb_printf("Dumping ftrace buffer:\n"); > > + kdb_printf("Dumping ftrace buffer (skipping %d entries):\n", > > + skip_entries); > > If someone *doesn't* need to skip any entries I'm not a fan of telling > them we are "skipping 0 entries"; it is more unnerving than helpful > ("huh? what does it need to tell me that no entried were skipped? > what makes the tracer skip entries?... Doh... I get it"). I agree. Probably best to have this: kdb_printf("Dumping ftrace buffer:\n"); if (skip_entries) kdb_printf("(skipping %d entries)\n", skip_entries); No reason to inject that skipping line in the first line. -- Steve