From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S263979AbTE0R5h (ORCPT ); Tue, 27 May 2003 13:57:37 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S264072AbTE0R4h (ORCPT ); Tue, 27 May 2003 13:56:37 -0400 Received: from nat9.steeleye.com ([65.114.3.137]:6407 "EHLO hancock.sc.steeleye.com") by vger.kernel.org with ESMTP id S264060AbTE0Rz4 (ORCPT ); Tue, 27 May 2003 13:55:56 -0400 Subject: Re: [BK PATCHES] add ata scsi driver From: James Bottomley To: Jens Axboe Cc: torvalds@transmeta.com, Linux Kernel In-Reply-To: <20030527171605.GL845@suse.de> References: <1053972773.2298.177.camel@mulgrave> <20030526181852.GL845@suse.de> <1053974830.1768.190.camel@mulgrave> <20030526190707.GM845@suse.de> <1053976644.2298.194.camel@mulgrave> <20030526193327.GN845@suse.de> <20030527123901.GJ845@suse.de> <1054045594.1769.24.camel@mulgrave> <20030527171605.GL845@suse.de> Content-Type: text/plain Content-Transfer-Encoding: 7bit X-Mailer: Ximian Evolution 1.0.8 (1.0.8-9) Date: 27 May 2003 14:09:05 -0400 Message-Id: <1054058946.1769.223.camel@mulgrave> Mime-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 2003-05-27 at 13:16, Jens Axboe wrote: > If you increase it again, the maps are resized. Is that a problem? Seems > ok to me. What I mean is that you allocate memory whenever the depth increases. Even if you have an array large enough to accommodate the increase (because you don't release when you decrease the tag depth). On further examination, there's also an invalid tag race: If a device is throttling, it might want to do a big decrease followed fairly quickly by a small increase. When it does the increase, you potentially still have outstanding tags above the new depth, which will now run off the end of your newly allocated tag array. James