From owner-freebsd-scsi@FreeBSD.ORG Tue Jun 3 18:22:55 2014 Return-Path: Delivered-To: freebsd-scsi@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 4B4A91F4 for ; Tue, 3 Jun 2014 18:22:55 +0000 (UTC) Received: from h2.funkthat.com (gate2.funkthat.com [208.87.223.18]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "funkthat.com", Issuer "funkthat.com" (not verified)) by mx1.freebsd.org (Postfix) with ESMTPS id 2516727F0 for ; Tue, 3 Jun 2014 18:22:55 +0000 (UTC) Received: from h2.funkthat.com (localhost [127.0.0.1]) by h2.funkthat.com (8.14.3/8.14.3) with ESMTP id s53IMqMf043503 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Tue, 3 Jun 2014 11:22:53 -0700 (PDT) (envelope-from jmg@h2.funkthat.com) Received: (from jmg@localhost) by h2.funkthat.com (8.14.3/8.14.3/Submit) id s53IMqvQ043502; Tue, 3 Jun 2014 11:22:52 -0700 (PDT) (envelope-from jmg) Date: Tue, 3 Jun 2014 11:22:52 -0700 From: John-Mark Gurney To: Warner Losh Subject: Re: Review needed Message-ID: <20140603182252.GF31367@funkthat.com> Mail-Followup-To: John-Mark Gurney , Warner Losh , freebsd-scsi@freebsd.org References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.4.2.3i X-Operating-System: FreeBSD 7.2-RELEASE i386 X-PGP-Fingerprint: 54BA 873B 6515 3F10 9E88 9322 9CB1 8F74 6D3F A396 X-Files: The truth is out there X-URL: http://resnet.uoregon.edu/~gurney_j/ X-Resume: http://resnet.uoregon.edu/~gurney_j/resume.html X-TipJar: bitcoin:13Qmb6AeTgQecazTWph4XasEsP7nGRbAPE X-to-the-FBI-CIA-and-NSA: HI! HOW YA DOIN? can i haz chizburger? X-Greylist: Sender passed SPF test, not delayed by milter-greylist-4.2.2 (h2.funkthat.com [127.0.0.1]); Tue, 03 Jun 2014 11:22:53 -0700 (PDT) Cc: freebsd-scsi@freebsd.org X-BeenThere: freebsd-scsi@freebsd.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: SCSI subsystem List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 03 Jun 2014 18:22:55 -0000 Warner Losh wrote this message on Mon, Jun 02, 2014 at 10:46 -0600: > The code that combines adjacent ranges for BIO_DELETEs to optimize > trims to the device assumes the list is sorted. Don't apply the > optimization of not sorting the queue when we have SSDs to the > delete_queue, since it causes more discard traffic to the drive. While I'm puzzled by this statement, if I remove the double negative, I get: Do apply the optimization of sorting the queue when we have SSDs to the delete_queue, since it (what the new optimizations?) causes more discard traffic to the drive. Do you mean previously? > one could argue that the higher levels should coalesce the trims, > that's not done today, so some optimization at this level is needed. > > Diffs and a (hopefully) cool review tool: https://phabric.freebsd.org/D142 Please include a raw diff... A Phabric is only for FreeBSD committers, it takes the rest of the community out of the ability to review. Thanks. -- John-Mark Gurney Voice: +1 415 225 5579 "All that I will do, has been done, All that I have, has not."