From owner-freebsd-hackers@FreeBSD.ORG Wed Jul 5 05:50:59 2006 Return-Path: X-Original-To: freebsd-hackers@freebsd.org Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 9567716A4E2 for ; Wed, 5 Jul 2006 05:50:59 +0000 (UTC) (envelope-from kamalpr@gmail.com) Received: from nz-out-0102.google.com (nz-out-0102.google.com [64.233.162.200]) by mx1.FreeBSD.org (Postfix) with ESMTP id 50E9243D53 for ; Wed, 5 Jul 2006 05:50:58 +0000 (GMT) (envelope-from kamalpr@gmail.com) Received: by nz-out-0102.google.com with SMTP id x3so741882nzd for ; Tue, 04 Jul 2006 22:50:57 -0700 (PDT) DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=beta; d=gmail.com; h=received:message-id:date:from:sender:to:subject:cc:in-reply-to:mime-version:content-type:references:x-google-sender-auth; b=mUJnmKqbYQeXYqxJTfJekPKLJmf/xFjUgm8X+NvEnbBTpn9KZwxj5ToseAJt7WsqEnqSMSxAEcT+ydzzBM3iIVJ5vglaaanIeRftku39FBmiqBJ4iyxV6jQrwXPQFrwcIlSSy+d8CWm+oLI4m6kVQkFwziHLKYKaLTqxhlmXACQ= Received: by 10.36.19.4 with SMTP id 4mr4792805nzs; Tue, 04 Jul 2006 22:50:57 -0700 (PDT) Received: by 10.36.18.18 with HTTP; Tue, 4 Jul 2006 22:50:57 -0700 (PDT) Message-ID: Date: Wed, 5 Jul 2006 11:20:57 +0530 From: "Kamal R. Prasad" Sender: kamalpr@gmail.com To: "Andriy Gapon" In-Reply-To: <44AA7607.2060302@icyb.net.ua> MIME-Version: 1.0 References: <44AA7607.2060302@icyb.net.ua> X-Google-Sender-Auth: 0af0e1b7a062c1d4 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Content-Disposition: inline X-Content-Filtered-By: Mailman/MimeDel 2.1.5 Cc: freebsd-hackers@freebsd.org Subject: Re: vop_stratgey name X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 05 Jul 2006 05:50:59 -0000 The block device has a head which is positioned at (platter, cylinder, sector) etc. before a write or read can be done. The strategy function chooses the order in which blocks are to be accessed so as to minimize the positioning required i.e. if we schedule closely located blocks of data for access -no matter when the request came in, that will speed up disk I/O. (In addition to this, the VM also does some strategizing of blocks to be read/written before passing them to the block driver.). regards -kamal On 7/4/06, Andriy Gapon wrote: > > > Maybe this question rather belongs to -questions (or -ancient-history), > but I thought I'd get a better chance here. > > I wonder why vop_strategy is named that, what meaning of "strategy" is > used here ? > I mean this is a read-or-write function for block devices, why > "strategy" :-) > > -- > Andriy Gapon > _______________________________________________ > freebsd-hackers@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-hackers > To unsubscribe, send any mail to "freebsd-hackers-unsubscribe@freebsd.org" >