From owner-freebsd-hackers@FreeBSD.ORG Fri Sep 19 23:35:09 2014 Return-Path: Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 96F78A5E for ; Fri, 19 Sep 2014 23:35:09 +0000 (UTC) Received: from mail-wi0-x22c.google.com (mail-wi0-x22c.google.com [IPv6:2a00:1450:400c:c05::22c]) (using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 342D9AE5 for ; Fri, 19 Sep 2014 23:35:09 +0000 (UTC) Received: by mail-wi0-f172.google.com with SMTP id em10so329531wid.5 for ; Fri, 19 Sep 2014 16:35:07 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:from:date:message-id:subject:to:content-type; bh=CDhY2Rg7TNqIEeK80VjLWcMF3XjDBq33H0A/d6Z58pQ=; b=VhLDEOYEUzlI1TFe6qZn3BRE4vNJj2xalFXuJQ31crXzSPkeWtl6V4NVasBBECcHH3 Tn+M7kVjbF4xfBS9+Oag3UecHUXx3o6G7NaipinEblK+6oya3pdEYcFpSJofFhMSFRwg 4trVtRdDPMrInaKhpylK6lYr+F6O0Z3lfZZWfbezyqeq7QEiXpxcgBfuEp8Szmljfjo9 OlJam6JwPwBYX2l9TuzheqUK6dE0r9bvGVvCVqo9I9+TSlDWex60J/9c8iffD7W/3rI+ UG8qdGbt2f6wBNZXrnUMP6uTgsxhVlVHfvjyq5MnribVi8PBrIsqWSfAvDqSE5A/GEGW SjUA== X-Received: by 10.180.184.40 with SMTP id er8mr59074028wic.31.1411169707359; Fri, 19 Sep 2014 16:35:07 -0700 (PDT) MIME-Version: 1.0 Received: by 10.216.192.66 with HTTP; Fri, 19 Sep 2014 16:34:27 -0700 (PDT) From: Artem Naluzhnyy Date: Sat, 20 Sep 2014 02:34:27 +0300 Message-ID: Subject: Deadline/NOOP-like I/O scheduler for hardware RAID controller To: freebsd-hackers@freebsd.org Content-Type: text/plain; charset=UTF-8 X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 19 Sep 2014 23:35:09 -0000 Hi, Will a Linux Deadline/NOOP-like I/O scheduler implementation using GEOM sched in FreeBSD have any performance improvements on hardware RAID controllers [1], SSD drives [2] or virtualization [3] like Linux has? Or there is a FreeBSD way to pass the I/O requests queue management to underlying (RAID/SSD controller or host OS) level? NOOP scheduler implementation in Linux looks quite simple [4]. [1] http://www.fishpool.org/post/2008/03/31/Optimizing-Linux-I/O-on-hardware-RAID [2] https://wiki.debian.org/SSDOptimization#Low-Latency_IO-Scheduler [3] http://www.sigops.org/sosp/sosp09/papers/hotstorage_4_boutcher.pdf [4] https://github.com/torvalds/linux/blob/master/block/noop-iosched.c -- Artem Naluzhnyy