From mboxrd@z Thu Jan 1 00:00:00 1970 From: James Bottomley Subject: Re: PATCH [5/15] qla2xxx: SG tablesize update Date: 14 Mar 2004 10:55:30 -0500 Sender: linux-scsi-owner@vger.kernel.org Message-ID: <1079279732.2108.40.camel@mulgrave> References: <20040314082444.GA3416@linux.local.home> <1079275768.2022.1.camel@mulgrave> <20040314145142.GL6955@suse.de> <1079276396.2022.8.camel@mulgrave> <20040314151809.GG19737@krispykreme> <1079278279.2022.34.camel@mulgrave> <20040314154713.GH19737@krispykreme> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Return-path: Received: from stat1.steeleye.com ([65.114.3.130]:24979 "EHLO hancock.sc.steeleye.com") by vger.kernel.org with ESMTP id S263378AbUCNPzo (ORCPT ); Sun, 14 Mar 2004 10:55:44 -0500 In-Reply-To: <20040314154713.GH19737@krispykreme> List-Id: linux-scsi@vger.kernel.org To: Anton Blanchard Cc: Jens Axboe , Andrew Vasquez , SCSI Mailing List On Sun, 2004-03-14 at 10:47, Anton Blanchard wrote: > Lets ignore the pci_map_sg problem and assume the qlogic driver did the > right thing. Whats to stop the upper layers from continually trying to > queue things when we run out of request slots? If its just sg_tablesize > then we are stuck with the current compromise (ie set it to something > reasonably low). Because on this type of failure, the driver will return SCSI_MLQUEUE_HOST_BUSY from its queuecommand routine. This will tell the mid layer not to try any more commands for the entire host until an outstanding one returns (thus hopefully freeing up enough resources). James