From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Hellwig Subject: Re: blk-mq problem on proliant DL380 G3 (cciss) Date: Wed, 29 Oct 2014 11:38:28 -0700 Message-ID: <20141029183828.GA31689@infradead.org> References: <545102FE.3010003@kernel.dk> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from bombadil.infradead.org ([198.137.202.9]:35075 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754020AbaJ2Sic (ORCPT ); Wed, 29 Oct 2014 14:38:32 -0400 Content-Disposition: inline In-Reply-To: <545102FE.3010003@kernel.dk> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: Jens Axboe Cc: Meelis Roos , linux-scsi@vger.kernel.org On Wed, Oct 29, 2014 at 09:08:46AM -0600, Jens Axboe wrote: > >Another test server with MPT SCSI RAID has similar problem, > >scsi_mode.use_blk_mq=0 cures it but I can not get good trace (no serail > >console). 3.18.0-rc2-00043-gf7e87a4 was tested there. > > The first issue looks like scsi cdrom and error handling, it must be leaking > requests hence we hang on allocation of a new one. cciss doesn't use blk_mq > regardless of the scsi setting. Does the mpt box also have a libata driven > cdrom? cciss does use scsi for CDROMs and other external devices, it is a bit of a mess. Meelis, did you also test scsi-mq on 3.17 and this is a regression, or was 3.18-rc2 the first kernel you tested?