From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hannes Reinecke Subject: Re: [PATCH] scsi: mq queue stall during command requeue Date: Fri, 20 Jan 2017 08:24:47 +0100 Message-ID: References: <1484835465-66514-1-git-send-email-hare@suse.de> <1484842302.2634.3.camel@sandisk.com> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 8bit Return-path: Received: from mx2.suse.de ([195.135.220.15]:36964 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751324AbdATHns (ORCPT ); Fri, 20 Jan 2017 02:43:48 -0500 In-Reply-To: <1484842302.2634.3.camel@sandisk.com> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: Bart Van Assche , "martin.petersen@oracle.com" Cc: "hch@lst.de" , "james.bottomley@hansenpartnership.com" , "linux-scsi@vger.kernel.org" , "jth@kernel.org" , "hare@suse.com" On 01/19/2017 05:11 PM, Bart Van Assche wrote: > On Thu, 2017-01-19 at 15:17 +0100, Hannes Reinecke wrote: >> When we're hitting a busy condition in queuecommand() we need to >> stop the hardware queue before calling blk_mq_delay_queue(); if >> we don't blk_mq_delay_queue() will not do anything and requeue >> will never triggered. >> >> Signed-off-by: Hannes Reinecke >> --- >> drivers/scsi/scsi_lib.c | 4 +++- >> 1 file changed, 3 insertions(+), 1 deletion(-) >> >> diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c >> index e9e1e14..4b1cbc6 100644 >> --- a/drivers/scsi/scsi_lib.c >> +++ b/drivers/scsi/scsi_lib.c >> @@ -1951,8 +1951,10 @@ static int scsi_queue_rq(struct blk_mq_hw_ctx *hctx, >> switch (ret) { >> case BLK_MQ_RQ_QUEUE_BUSY: >> if (atomic_read(&sdev->device_busy) == 0 && >> - !scsi_device_blocked(sdev)) >> + !scsi_device_blocked(sdev)) { >> + blk_mq_stop_hw_queue(hctx); >> blk_mq_delay_queue(hctx, SCSI_QUEUE_DELAY); >> + } >> break; >> case BLK_MQ_RQ_QUEUE_ERROR: >> /* > > You may want to add Fixes: 52d7f1b5c2f3 (blk-mq: Avoid that requeueing > starts stopped queues). See also > https://www.spinics.net/lists/linux-block/msg06144.html. > Yes indeed. But the powers that be still ponder if it should be fixed in the SCSI stack or whether it's a generic fix for blk_mq_delay_queue(). Cheers, Hannes -- Dr. Hannes Reinecke Teamlead Storage & Networking hare@suse.de +49 911 74053 688 SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg GF: F. Imendörffer, J. Smithard, J. Guild, D. Upmanyu, G. Norton HRB 21284 (AG Nürnberg)