Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933768AbZAPNIx (ORCPT ); Fri, 16 Jan 2009 08:08:53 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1760689AbZAPNIl (ORCPT ); Fri, 16 Jan 2009 08:08:41 -0500 Received: from mail-bw0-f21.google.com ([209.85.218.21]:56063 "EHLO mail-bw0-f21.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760665AbZAPNIj (ORCPT ); Fri, 16 Jan 2009 08:08:39 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:to:subject:cc:in-reply-to:mime-version :content-type:content-transfer-encoding:content-disposition :references; b=CW2AbebFX1p+kda/AY0PsF3P87hOkJORiCHeDayk9CVVhK+U6jrUBL7nXyTULKwcW4 U+uV035X5mVw+9WNtvVjwSNGee2zieFzr0FHnpjiCQECNFRctxFGpiq4F0qbIUpvegxY zKV2eTl9SCDNs8S8rZWlKZz4VKNLed3QhOPIU= Message-ID: Date: Fri, 16 Jan 2009 14:08:36 +0100 From: "=?ISO-8859-1?Q?Fr=E9d=E9ric_Weisbecker?=" To: "Ingo Molnar" Subject: Re: [PATCH 0/2] ftrace: updates to tip Cc: "Steven Rostedt" , linux-kernel@vger.kernel.org, "Andrew Morton" , "Chris Mason" In-Reply-To: <20090116112345.GC20082@elte.hu> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <20090116004050.273665842@goodmis.org> <20090116112345.GC20082@elte.hu> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2461 Lines: 76 2009/1/16 Ingo Molnar : > > * Steven Rostedt wrote: > >> Ingo, >> >> The first patch is critical, and needs to stay with trace_output.c Not >> that critical since trace_output.c is not in mainline yet. >> >> The second patch gives the ability to stack trace functions. I've been >> leery about adding this and still keep it a separate option from the >> "stacktrace" that already exists. This is because when enabled with no >> filtering, the lag between typing and seeing what is typed can be up to >> 10 seconds or more. > > Btw., is this true even if frame pointers are enabled? When frame pointers > are disabled we scan the full kernel stack => that can be quite slow if > every kernel function is traced ;-) Hi Ingo, The function tracer selects Frame pointers :-) Frederic. >> I made the function stack trace an option attached to the function >> tracer, so it must be enabled after the function tracer has been set. >> This still needs to be updated in ftrace.txt. > > maybe we could drive this via the filter API? Something like: > > echo "*btrfs*:stacktrace" >> set_filter_functions > > Would automatically mean that those functions will all generate > stacktraces too. Note how safe this API is by default: the filter is used > for a narrow scope of functions anwyay. To get it for all kernel functions > one would have to do: > > echo "*:stacktrace" >> set_filter_functions > > Which one cannot do accidentally. > > What do you think? > >> The following patches are in: >> >> git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace.git >> >> branch: tip/devel >> >> >> Lai Jiangshan (1): >> ftrace: fix trace_output >> >> Steven Rostedt (1): >> ftrace: add stack trace to function tracer >> >> ---- >> kernel/trace/trace.c | 26 ++++++++---- >> kernel/trace/trace.h | 7 +++ >> kernel/trace/trace_functions.c | 84 ++++++++++++++++++++++++++++++++++++++++ >> kernel/trace/trace_output.c | 65 +++++++++++++++---------------- >> kernel/trace/trace_output.h | 4 +- >> 5 files changed, 141 insertions(+), 45 deletions(-) > > Pulled into tip/tracing/ftrace, thanks Steve! > > Ingo > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/