From mboxrd@z Thu Jan 1 00:00:00 1970 From: Douglas Gilbert Subject: Re: [PATCH v2 6/6] scsi_debug: allow huge transfer length for read/write commands Date: Mon, 02 Jun 2014 13:06:13 -0400 Message-ID: <538CAF05.6080505@interlog.com> References: <1401717409-5236-1-git-send-email-akinobu.mita@gmail.com> <1401717409-5236-7-git-send-email-akinobu.mita@gmail.com> Reply-To: dgilbert@interlog.com Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from smtp.infotech.no ([82.134.31.41]:58958 "EHLO smtp.infotech.no" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751830AbaFBRGS (ORCPT ); Mon, 2 Jun 2014 13:06:18 -0400 In-Reply-To: <1401717409-5236-7-git-send-email-akinobu.mita@gmail.com> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: Akinobu Mita , linux-scsi@vger.kernel.org Cc: Christoph Hellwig , Jens Axboe , "James E.J. Bottomley" On 14-06-02 09:56 AM, Akinobu Mita wrote: > This change enables to test read/write commands with huge transfer > length such as 1GB. For example: > > # modprobe scsi_debug dev_size_mb=1024 clustering=1 opts=1 > # cat /sys/block/$DEV/queue/max_hw_sectors_kb > \ > /sys/block/$DEV/queue/max_sectors_kb > # fio --name=test --rw=write --bs=1g --size=1g --filename=/dev/$DEV \ > --mem=mmaphuge --direct=1 > > The data type of max_sectors in scsi_host_template has been extended > to unsigned int by the previous change. So we can increase it from > 0xffff to 0xffffffff to allow such huge transfer length. > > Also, this increases sg_tablesize and max_segment_size, otherwise the > maximum transfer length is limited to 64MB. > (sg_tablesize * max_segment_size = 256 * 256KB) > > Signed-off-by: Akinobu Mita > Reviewed-by: Christoph Hellwig > Cc: Christoph Hellwig > Cc: Jens Axboe > Cc: "James E.J. Bottomley" > Cc: Douglas Gilbert > Cc: linux-scsi@vger.kernel.org Acked by: Douglas Gilbert