From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Return-Path: Sender: Tejun Heo Date: Wed, 11 Apr 2018 10:07:33 -0700 From: "tj@kernel.org" To: Israel Rukshin Cc: Sagi Grimberg , Bart Van Assche , "ming.lei@redhat.com" , "hch@lst.de" , "maxg@mellanox.com" , "linux-block@vger.kernel.org" , "stable@vger.kernel.org" , "axboe@kernel.dk" Subject: Re: [PATCH v4] blk-mq: Fix race conditions in request timeout handling Message-ID: <20180411170733.GM793541@devbig577.frc2.facebook.com> References: <20180410152553.GC22340@ming.t460p> <20180410153031.GO3126663@devbig577.frc2.facebook.com> <20180410153812.GA3219@ming.t460p> <20180410154043.GP3126663@devbig577.frc2.facebook.com> <20180410213323.GC793541@devbig577.frc2.facebook.com> <20180410215456.GD793541@devbig577.frc2.facebook.com> <7a586854-33a5-fe3b-6d94-24d305696126@grimberg.me> <0da96ded-7bfc-e6a8-428c-1ce1e3db0378@mellanox.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 In-Reply-To: <0da96ded-7bfc-e6a8-428c-1ce1e3db0378@mellanox.com> List-ID: Hello, Israel. On Wed, Apr 11, 2018 at 07:16:14PM +0300, Israel Rukshin wrote: > >Just noticed this one, this looks interesting to me as well. Israel, > >can you run your test with this patch? > > Yes, I just did and it looks good. Awesome. > >>+++ b/include/linux/blkdev.h > >>@@ -227,6 +227,8 @@ struct request { > >>� ����� unsigned int extra_len;��� /* length of alignment and padding */ > >>� +��� bool missed_completion; > >>+ > > > >Would be nicer if we can flag this somewhere instead of adding a hole to > >struct request... I missed it before. It's actually being put in an existing hole, so the struct size stays the same before and after. It's a bit of cheating cuz this is one of the two holes which can be removed by swapping two fields. Re. making it a flag, regardless of whether this is a flag or a separate field, we need to add a new field because there currently is no field which can be modified by the party who doesn't own the request, so if we make it a flag, we need to add sth like unsigned long atom_flags. Thanks. -- tejun