From mboxrd@z Thu Jan 1 00:00:00 1970 Received: with ECARTIS (v1.0.0; list linux-mips); Thu, 22 Oct 2009 23:10:09 +0200 (CEST) Received: from mail-ew0-f216.google.com ([209.85.219.216]:56240 "EHLO mail-ew0-f216.google.com" rhost-flags-OK-OK-OK-OK) by ftp.linux-mips.org with ESMTP id S1493335AbZJVVKC (ORCPT ); Thu, 22 Oct 2009 23:10:02 +0200 Received: by ewy12 with SMTP id 12so9349779ewy.0 for ; Thu, 22 Oct 2009 14:09:56 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:received:date:from:to:cc :subject:message-id:references:mime-version:content-type :content-disposition:in-reply-to:user-agent; bh=2VqvCfKnzjq3cObpkhC6zNjWWxZvnqhlaihqzw1YMZY=; b=ll4IFe+HcpuLos1//7Y94+mVDTebHXM1eMU9jJSMRyDw47mcdYoGCIw01g12KQRgJd UHkwjwbxsjDIxxkW4Odt5YiMJLctZkVhfCdx9AZYLgcV/ws+BKs7aPkTg0ZcUi98yTvv Cyi4yE4TJi3kBhW/A1ztOMGwKbXwGOsCUEEVM= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=date:from:to:cc:subject:message-id:references:mime-version :content-type:content-disposition:in-reply-to:user-agent; b=GL/3V7M9VOSRoFx2pnvn/iwZm3JRpA0WvH2RQN2wtyXWeWw2JaIICd0OOZ3iML1g0/ BEawQCqN79yQ/1Mg/4B34FATxEWrMB5yE2MFoYBR6bRKbrLGRl7gpCH1n/EBkj0X3Txa 2KlGZHxtsrWyDiAGGG1KUqBRSVkDDpzmgzqbI= Received: by 10.211.154.18 with SMTP id g18mr4687210ebo.70.1256245796492; Thu, 22 Oct 2009 14:09:56 -0700 (PDT) Received: from nowhere (ADijon-552-1-49-221.w92-138.abo.wanadoo.fr [92.138.48.221]) by mx.google.com with ESMTPS id 7sm4527341eyb.40.2009.10.22.14.09.52 (version=SSLv3 cipher=RC4-MD5); Thu, 22 Oct 2009 14:09:54 -0700 (PDT) Received: by nowhere (nbSMTP-1.00) for uid 1000 (using TLSv1/SSLv3 with cipher RC4-MD5 (128/128 bits)) fweisbec@gmail.com; Thu, 22 Oct 2009 23:09:54 +0200 (CEST) Date: Thu, 22 Oct 2009 23:09:52 +0200 From: Frederic Weisbecker To: Steven Rostedt Cc: Adam Nemet , David Daney , wuzhangjin@gmail.com, Richard Sandiford , linux-kernel@vger.kernel.org, linux-mips@linux-mips.org, Thomas Gleixner , Ralf Baechle , Nicholas Mc Guire Subject: Re: [PATCH -v4 4/9] tracing: add static function tracer support for MIPS Message-ID: <20091022210950.GA10041@nowhere> References: <028867b99ec532b84963a35e7d552becc783cafc.1256135456.git.wuzhangjin@gmail.com> <2f73eae542c47ac5bbb9f7280e6c0271d193e90d.1256135456.git.wuzhangjin@gmail.com> <3f0d3515f74a58f4cfd11e61b62a129fdc21e3a7.1256135456.git.wuzhangjin@gmail.com> <1256138686.18347.3039.camel@gandalf.stny.rr.com> <1256233679.23653.7.camel@falcon> <4AE0A5BE.8000601@caviumnetworks.com> <19168.49354.525249.654494@ropi.home> <1256244726.20866.802.camel@gandalf.stny.rr.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1256244726.20866.802.camel@gandalf.stny.rr.com> User-Agent: Mutt/1.5.18 (2008-05-17) Return-Path: X-Envelope-To: <"|/home/ecartis/ecartis -s linux-mips"> (uid 0) X-Orcpt: rfc822;linux-mips@linux-mips.org Original-Recipient: rfc822;linux-mips@linux-mips.org X-archive-position: 24456 X-ecartis-version: Ecartis v1.0.0 Sender: linux-mips-bounce@linux-mips.org Errors-to: linux-mips-bounce@linux-mips.org X-original-sender: fweisbec@gmail.com Precedence: bulk X-list: linux-mips On Thu, Oct 22, 2009 at 04:52:06PM -0400, Steven Rostedt wrote: > On Thu, 2009-10-22 at 13:30 -0700, Adam Nemet wrote: > > > > Speaking of performance, -pg also affects the instruction scheduling freedom > > of the compiler in the prologue. With profiling, we limit optimizations not > > to move instructions in and out of the prologue. > > > > Also note that for functions invoked via tail call you won't get an exit > > event. E.g. if bar is tail-called from foo: > > > > foo entered > > bar entered > > foo/bar exited > > > > However, this is not MIPS-specific and you can always disable tail calls > > with -fno-optimize-sibling-calls. Ouch.. > The question is, would bar have a _mcount call? So far, we have not had > any issues with this on either x86 nor PPC. Nothing would prevent that I guess. I mean, we are doing a very specific use of -pg, and common uses wouldn't require to disable the mcount call on bar in this situation, so it's not something that -pg is supposed to care about. > /me knocks on wood. Me too (but not so hard...)