From mboxrd@z Thu Jan 1 00:00:00 1970 From: John Kacur Subject: Re: [PATCH:resend] rt: Remove CONFIG_STACK_TRACER from DEBUG_COUNT, and fix reminder block Date: Wed, 28 Apr 2010 21:22:02 +0200 Message-ID: References: <1272396342-12504-1-git-send-email-jkacur@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: Clark Williams , Steven Rostedt , lkml , rt-users To: Thomas Gleixner Return-path: Received: from mail-fx0-f46.google.com ([209.85.161.46]:40007 "EHLO mail-fx0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753827Ab0D1TWG convert rfc822-to-8bit (ORCPT ); Wed, 28 Apr 2010 15:22:06 -0400 In-Reply-To: Sender: linux-rt-users-owner@vger.kernel.org List-ID: On Tue, Apr 27, 2010 at 10:39 PM, Thomas Gleixner = wrote: > On Tue, 27 Apr 2010, John Kacur wrote: > >> This fix does two things. > > This changelog does suck in more than two ways. > >> 1. It reverts commit 3e39399ef4a742d994570488994be93ef17d4ef5. >> - The above commit added back a warning about CONFIG_STACK_TRACER >> NOT because the warning was necessary but to fix-up a problem where = you could >> get an empty REMINDER block in the demg. > > The CONFIG_STACK_TRACER printk has been there before and got dropped > for whatever reason, but the DEBUG_COUNT accounting of > CONFIG_STACK_TRACER still remained. > > So the conclusion that the printk needs to be added back is _NOT_ > completely unreasonable. > >> However, CONFIG_STACK_TRACER really should not be in the reminder bl= ock. >> Even when configured-in it is not enabled, and thus has neglible imp= act. > > That argument is bogus as it applies to most of the tracing related > config options. Not quite. Some of the tracing options are believed to have an impact even when not enabled. In particular irqsoff and preemptoff still call a function. Not sure how minimal the impact is, but it isn't zero. > >> 2. It removes CONFIG_STACK_TRACER from DEBUG_COUNT which is the prop= er fix >> for the empty REMINDER block problem. > > It's the proper fix if the warning is not justified, which is not > clear at all. At least not from your changelog. > > I do not mind the patch per se, but > > 1) the changelog should simply say: > > =A0 rt: Remove CONFIG_STACK_TRACER from REMINDER block > > =A0 Reason: It does not matter because .... > > 2) the patch should cover _all_ tracing options which have no > =A0 considerable latency impact when just compiled in and not default > =A0 enabled. > Okay, you make some good points, although I'm having a hard time finding other CONFIGS to safely cut. Respinning the patch. Thanks for your reply. -- To unsubscribe from this list: send the line "unsubscribe linux-rt-user= s" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html