From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Bart Van Assche To: "hch@lst.de" , "keith.busch@linux.intel.com" CC: "jianchao.w.wang@oracle.com" , "keith.busch@intel.com" , "linux-block@vger.kernel.org" , "linux-nvme@lists.infradead.org" , "axboe@kernel.dk" , "ming.lei@redhat.com" Subject: Re: [RFC PATCH 3/3] blk-mq: Remove generation seqeunce Date: Wed, 18 Jul 2018 21:05:40 +0000 Message-ID: <7aadef775fe67c3656830a8b9b029ec03cca3d26.camel@wdc.com> References: <20180521231131.6685-4-keith.busch@intel.com> <20180712192437.GA16839@localhost.localdomain> <7cad25b821c3a640e036f28ff1bbe51e7362d25d.camel@wdc.com> <20180713154346.GA18955@localhost.localdomain> <20180713184712.GA19419@localhost.localdomain> <291a13b35af1b65fbbe99a3a9cfc7d570a620cd9.camel@wdc.com> <20180713235807.GA19967@localhost.localdomain> <20180718195650.GA20336@lst.de> <20180718203936.GA21011@lst.de> In-Reply-To: <20180718203936.GA21011@lst.de> Content-Type: text/plain; charset="utf-7" MIME-Version: 1.0 List-ID: On Wed, 2018-07-18 at 22:39 +-0200, hch+AEA-lst.de wrote: +AD4- On Wed, Jul 18, 2018 at 09:56:50PM +-0200, hch+AEA-lst.de wrote: +AD4- +AD4- The important bit is that we need to fix this issue quickly. W= e are +AD4- +AD4- past -rc5 so I'm rather concerned about anything too complicate= d. +AD4- +AD4-=20 +AD4- +AD4- I'm not even sure SCSI has a problem with multiple completions = happening +AD4- +AD4- at the same time, but it certainly has a problem with bypassing +AD4- +AD4- blk+AF8-mq+AF8-complete+AF8-request from the EH path. +AD4- +AD4-=20 +AD4- +AD4- I think we can solve this properly, but I also think we are way= to late +AD4- +AD4- in the 4.18 cycle to fix it properly. For now I fear we'll jus= t have +AD4- +AD4- to revert the changes and try again for 4.19 or even 4.20 if we= don't +AD4- +AD4- act quickly enough. +AD4-=20 +AD4- So here is a quick attempt at the revert while also trying to keep +AD4- nvme working. Keith, Bart, Jianchao - does this looks reasonable +AD4- as a 4.18 band aid? +AD4-=20 +AD4- http://git.infradead.org/users/hch/block.git/shortlog/refs/heads/blk-= eh-revert Hello Christoph, A patch series that first reverts the following patches: +ACo- blk-mq: Fix timeout handling in case the timeout handler returns BLK+= AF8-EH+AF8-DONE +ACo- block: fix timeout changes for legacy request drivers +ACo- blk-mq: don't time out requests again that are in the timeout handler +ACo- blk-mq: simplify blk+AF8-mq+AF8-rq+AF8-timed+AF8-out +ACo- block: remove BLK+AF8-EH+AF8-HANDLED +ACo- block: rename BLK+AF8-EH+AF8-NOT+AF8-HANDLED to BLK+AF8-EH+AF8-DONE +ACo- blk-mq: Remove generation seqeunce and next renames BLK+AF8-EH+AF8-NOT+AF8-HANDLED again into BLK+AF8-EH+AF8-D= ONE would probably be a lot easier to review. Thanks, Bart.