From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from pigeon.gentoo.org ([208.92.234.80] helo=lists.gentoo.org) by finch.gentoo.org with esmtp (Exim 4.60) (envelope-from ) id 1RcgFM-00088A-Bo for garchives@archives.gentoo.org; Mon, 19 Dec 2011 16:39:28 +0000 Received: from pigeon.gentoo.org (localhost [127.0.0.1]) by pigeon.gentoo.org (Postfix) with SMTP id 256CF21C0EF; Mon, 19 Dec 2011 16:39:16 +0000 (UTC) Received: from mail-we0-f181.google.com (mail-we0-f181.google.com [74.125.82.181]) by pigeon.gentoo.org (Postfix) with ESMTP id 47CD6E0693 for ; Mon, 19 Dec 2011 16:38:06 +0000 (UTC) Received: by werm12 with SMTP id m12so1713282wer.40 for ; Mon, 19 Dec 2011 08:38:06 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=mime-version:sender:in-reply-to:references:from:date :x-google-sender-auth:message-id:subject:to:content-type :content-transfer-encoding; bh=coVEKihZmjgYmw6LF2C+BTqoBf6luOzXLTloPdZtae8=; b=N00IJnzoCeCFlNH+8ROIA+bZhkGHfyc2n6bGzB1MsK/FMDiw4MTNGJegFnXFrDQmkW d92ctqNFHYeKXBd4aT6XM3Akp6E5Q5jzP8AA0d4FAZJur/neZNPMCYnyqc0cJULp5Ww+ SaWhPU2aKWDam1LGbnx0+lENM+Auk0MQmb2CA= Received: by 10.216.136.70 with SMTP id v48mr7325203wei.48.1324312686183; Mon, 19 Dec 2011 08:38:06 -0800 (PST) Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-Id: Gentoo Linux mail X-BeenThere: gentoo-user@lists.gentoo.org Reply-to: gentoo-user@lists.gentoo.org MIME-Version: 1.0 Sender: paul.hartman@gmail.com Received: by 10.227.10.81 with HTTP; Mon, 19 Dec 2011 08:37:45 -0800 (PST) In-Reply-To: <4EEED697.4030000@gmail.com> References: <20111217210709.GA1740@waltdnes.org> <20111218011054.GA2804@waltdnes.org> <20111218103449.GA21102@waltdnes.org> <20111219000522.GA22397@waltdnes.org> <4EEE82A5.2010909@gmail.com> <4EEED697.4030000@gmail.com> From: Paul Hartman Date: Mon, 19 Dec 2011 10:37:45 -0600 X-Google-Sender-Auth: Xc18jm1WMmrtDuI_-icsx7FSoTY Message-ID: Subject: Re: [gentoo-user] A tale of computing thud and blunder To: gentoo-user@lists.gentoo.org Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable X-Archives-Salt: cf2c3e1e-6c04-4f99-a8ae-03cbc16647b1 X-Archives-Hash: 23eed2221c931d3149c69b2c4d8d3d66 On Mon, Dec 19, 2011 at 12:15 AM, Dale wrote: > Pandu Poluan wrote: >> >> >> Kind of like what I always do when I switch from -march=3Dnocona to >> -march=3Dnative. (Usually I use -march=3Dnocona to ensure seamless VM mi= gration >> on my XenServer-equipped boxen, but for some VMs, i.e., those requiring = me >> to wring out every last drop of performance, I go native.) >> >> That said, if you want to experience fully the "GCC Graphite" >> optimizations, you'll also want to do emerge -ev ;-) >> >> Rgds, >> > > > Is Graphite worthwhile on a desktop system or is it better suited for > servers or both? =A0I found this but still not sure what it is intended f= or: > > http://gcc.gnu.org/wiki/Graphite/4.5 > > Are there any reasons to leave this be for a while? =A0You know, bugs or > packages that don't work with it? I used it for @world and ran into a couple times when things were broken with it enabled... Don't really remember specifics. I didn't notice any perceivable speed difference, so I stopped using it just to simplify things in the future. :) In general,I have changed my CFLAGS to be less aggressive over the past years. I started with the most aggressive optimizations, and using -march=3Dwhatever... At some point I researched compile times for different optimizations and realized some packages were taking tens of minutes longer to compile! Surely whatever potential speed increase of -O3 vs -O2 was not going to give me tens of minutes cumulatively. If there is a package that really benefits from some specific optimization (and doesn't already set those flags itself in the ebuild), I'll set the CFLAGS for that individual package but leave the rest of world very simplistic. Same with -march, I've gone to using -mtune instead, after having to move hard drives into a system with different CPU feature set. And for virtual machines (in hosts I don't control, especially), they could be migrated to some other machine without my knowledge, and i don't want it to stop working if that happens.