From owner-freebsd-questions@FreeBSD.ORG Mon Sep 8 23:45:08 2014 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 97EAE5BC; Mon, 8 Sep 2014 23:45:08 +0000 (UTC) Received: from mail-in5.apple.com (mail-out5.apple.com [17.151.62.27]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 6DF9A83B; Mon, 8 Sep 2014 23:45:07 +0000 (UTC) Received: from mail-out.apple.com (mail-out.apple.com [17.151.62.49]) (using TLS with cipher RC4-MD5 (128/128 bits)) (Client did not present a certificate) by mail-in5.apple.com (Apple Secure Mail Relay) with SMTP id 55.01.17540.38F3E045; Mon, 8 Sep 2014 16:45:07 -0700 (PDT) MIME-version: 1.0 Content-transfer-encoding: 7BIT Content-type: text/plain; CHARSET=US-ASCII Received: from relay3.apple.com ([17.128.113.83]) by local.mail-out.apple.com (Oracle Communications Messaging Server 7.0.5.30.0 64bit (built Oct 22 2013)) with ESMTP id <0NBL00713WMICNW0@local.mail-out.apple.com>; Mon, 08 Sep 2014 16:45:07 -0700 (PDT) X-AuditID: 11973e13-f793e6d000004484-09-540e3f8398b6 Received: from [17.149.227.93] (Unknown_Domain [17.149.227.93]) (using TLS with cipher AES128-SHA (128/128 bits)) (Client did not present a certificate) by relay3.apple.com (Apple SCV relay) with SMTP id 8F.26.08757.68F3E045; Mon, 8 Sep 2014 16:45:11 -0700 (PDT) Subject: Re: A litmus check request From: Charles Swiger In-reply-to: <540E33BB.9000606@FreeBSD.org> Date: Mon, 08 Sep 2014 16:44:34 -0700 Message-id: References: <540E21A0.4070103@comcast.net> <540E33BB.9000606@FreeBSD.org> To: Matthew Seaman , dcbdbis@comcast.net X-Mailer: Apple Mail (2.1878.6) X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFtrMLMWRmVeSWpSXmKPExsUiON3OULfZni/E4PZCPYuXXzexWLy+9p/N gcljxqf5LAGMUVw2Kak5mWWpRfp2CVwZ+3/dYyq4wlXx/6xEA+NOji5GTg4JAROJm5snMkPY YhIX7q1n62Lk4hASmMUkcXx+KwtIgldAUOLH5HtANgcHs4C8xMHzsiBhZgEtie+PQEpA6puY JNZsvswGM3Ta0ldQg3qZJLZ+OscG0iwsoCzxvFUcxGQTUJOYMJEHpJxTQFvi/IxTYKtYBFQl Dm+4zwgxX1ei6cZbRogTrCRWNc0Bs4UEPCWW/+phArFFBGwl1i/ZB3W/vMSHD8fZQdZKCPxm lWj69otxAqPwLCQvzEJ4YRaSFxYwMq9iFMpNzMzRzcwz1UssKMhJ1UvOz93ECAll4R2Mp1dZ HWIU4GBU4uFNuMoTIsSaWFZcmXuIUZqDRUmcl9OOL0RIID2xJDU7NbUgtSi+qDQntfgQIxMH p1QDo15x8pL1V6PvruQ78+A2C9ej1mnCy1TrxKd6rdiy731UxFTbHI6SjXJhx173GHmtnciU 9W1HNLeLiuTyCSc5nzlJBUowdD00+XN087OW+Sz24QvYzOYfuVkntWnjLLH70XlVD1eHKvJv +9a2dp9nr0/qe2kJYyYxRbFtZfV511NfT7/h9PiLixJLcUaioRZzUXEiAEz0GcpGAgAA X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFlrCLMWRmVeSWpSXmKPExsUiOPVxrG67PV+IwYZOLotrk1ksXn7dxGLx +tp/Ngdmj8mP5zB6zPg0nyWAKYrLJiU1J7MstUjfLoErY/+ve0wFV7gq/p+VaGDcydHFyMkh IWAiMW3pKzYIW0ziwr31QDYXh5BAL5PE8V2/WEESzAJaEjf+vWQCsXkFDCSW7NrE3MXIwSEs oCzxvFUcxGQTUJOYMJEHpIJTQFvi4LZDzCA2i4CKxLw/u6Gm6Eo03XjLCGHLS2x/O4cZYqKV ROvvjewgtpCAp8TyXz1gm0QE7CXudf9ggThNXuLDh+PsExj5ZyE5aBaSg2YhGbuAkXkVo0BR ak5ipbFeYkFBTqpecn7uJkZQ2DUUBu9g/LPM6hCjAAejEg8vx2WeECHWxLLiytxDjBIczEoi vH7WfCFCvCmJlVWpRfnxRaU5qcWHGKU5WJTEeae/5AgREkhPLEnNTk0tSC2CyTJxcEo1MLpp l4sqqa6ZfH/2fvFb7EL3psvL3L7zsT8yaIldjlb1lWmHxH+9+F5jv2VVXu+HaJsZe62N7m9+ d8RqeY4599q9v7R2PvO/umx9AbOTGt+3O+eE1n1Z9inXUKXFicfn3k8zC04/xt+zOneGmrFv P7C9bmcba3TY+RVF7I8qt8jEii2Xm3NRQ1SJpTgj0VCLuag4EQAIu0bhNwIAAA== Cc: FreeBSD - X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 08 Sep 2014 23:45:08 -0000 On Sep 8, 2014, at 3:54 PM, Matthew Seaman wrote: > On 08/09/2014 22:37, Dave Babb wrote: >> I am asking that someone please review this attached fstab and validate >> for me, that at no time will any compilation intermediate files, or ".o" >> files will be written to the SSD. I am trying to protect the SSD. > > That should work pretty well. However what's your swapinfo say? If you > do happen to fill up RAM with your tmpfs, you'll end up swapping a bunch > of memory pages out to the swap area, and if your swap is on the SSD, > then you've pretty much defeated the object of the whole exercise. While it's certainly true that being able to keep tmpfs entirely in RAM is highly desirable, it's likely that hitting an SSD for swap would generate less wear on the drive than writing compiler temp files directly. Sure, you don't really want to swap onto an SSD if you can help it, but paging and swapping activities are generally page-aligned, and so they cause less write amplification than filesystem writes are likely to cause. > That aside, it looks good. If it's possible, adding noatime to the > tmpfs mount flags will help with performance. Sure. Also feeding -pipe to the compilers will try to use pipelines between the stages of the toolchain rather than temp files. Regards, -- -Chuck