From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from lists.gentoo.org (pigeon.gentoo.org [208.92.234.80]) by finch.gentoo.org (Postfix) with ESMTP id BA30E138010 for ; Thu, 6 Sep 2012 14:43:05 +0000 (UTC) Received: from pigeon.gentoo.org (localhost [127.0.0.1]) by pigeon.gentoo.org (Postfix) with SMTP id D9CDBE09DC; Thu, 6 Sep 2012 14:41:35 +0000 (UTC) Received: from mail-bk0-f53.google.com (mail-bk0-f53.google.com [209.85.214.53]) by pigeon.gentoo.org (Postfix) with ESMTP id 45B1CE0996 for ; Thu, 6 Sep 2012 14:33:49 +0000 (UTC) Received: by bkwj4 with SMTP id j4so858894bkw.40 for ; Thu, 06 Sep 2012 07:33:49 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type; bh=FBsQ96COoLabpK41EOLkVJ7FxaLt5fvW0atZs4Wd3vc=; b=Qz2D6VjSGEvfxMmThUVUkKwbKR9Psb2Tc0HcrxyEssrloKCfIxtgTN1ceXPMgqFRPu EX+jc6MF2ahpOSaLUxCAErI0q32vDXHGfGXvonO1yk48yk1iubJyeZCi4T1K5o+4LVaO zTjZZ+apMiO/+uhS11kUEahsRSREQlBMn1CJYTqyD9FeEW6G7Y5wkHepxCjFP+lgj32Y GO73fThMegEu88C6/g48rBxTwvisHvy+Y2qi9U2bdvkSVakpk2Ehae0p7qbq0vkHpQyN kYP8pfZmefjfnySZNsRFFT5cvwAJ/9Xr/gh7dPM78xttKxJjkEOyFR4RvADxC3lf4sQR IO/g== 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 Received: by 10.204.145.76 with SMTP id c12mr1112842bkv.70.1346942029372; Thu, 06 Sep 2012 07:33:49 -0700 (PDT) Received: by 10.204.112.211 with HTTP; Thu, 6 Sep 2012 07:33:49 -0700 (PDT) In-Reply-To: <5048B120.2030905@gmail.com> References: <504791EB.2030103@gmail.com> <20120906065755.GA2442@nicolas-desktop> <504869AB.20908@gmail.com> <20120906104744.7f0972a7@hactar.digimed.co.uk> <504876B5.7050001@gmail.com> <20120906112003.7b1235bd@hactar.digimed.co.uk> <50487E9A.3060200@gmail.com> <20120906111136.GC2442@nicolas-desktop> <5048898C.7070301@gmail.com> <20120906134646.GH2442@nicolas-desktop> <5048B120.2030905@gmail.com> Date: Thu, 6 Sep 2012 10:33:49 -0400 Message-ID: Subject: Re: [gentoo-user] Re: aligning SSD partitions From: Michael Mol To: gentoo-user@lists.gentoo.org Content-Type: text/plain; charset=UTF-8 X-Archives-Salt: 643b608c-d8fa-44bf-a7bc-b4dfdba85668 X-Archives-Hash: b83350ae49ee5d6d0fcab7c92f8ac215 On Thu, Sep 6, 2012 at 10:20 AM, Dale wrote: > Nicolas Sebrecht wrote: >> The 06/09/12, Dale wrote: >> >>> Not quite. The theory is that if you put portages work directory on >>> tmpfs, then all the writes and such are done in ram which is faster. >> No! This is too much simplistic view to explain what you see. >> >> In practice, _all_ the writes always happen in RAM whatever backend >> storage you use. >> >> The difference you could see is if there is not enough RAM for the >> kernel cache, it will have to wait for the backend storage. >> > > > OK. Step by step here so hopefully you and Neil can follow. > > Freshly booted system. > Clear caches just to be sure > > emerge foo with portages work directory on tmpfs > clear caches again > emerge foo with portages work directory on disk > clear caches again. > emerge foo with portages work directory on tmpfs > clear caches again > emerge foo with portages work directory on disk > > You repeat this enough times and you see that it doesn't matter if > portage's work directory is on disk or on tmpfs. If you have enough RAM, then this is certainly true. Nobody is disputing that. They've been trying to explain that there's a difference when you _don't_ have that much RAM, and they've been trying to explain the mechanism behind that. -- :wq