From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Return-Path: Subject: Re: [PATCH 08/10] block: provide a generic_make_request_fast helper To: Christoph Hellwig , Jens Axboe Cc: Keith Busch , linux-nvme@lists.infradead.org, linux-block@vger.kernel.org References: <20170823175815.3646-1-hch@lst.de> <20170823175815.3646-9-hch@lst.de> From: Sagi Grimberg Message-ID: <326ee3b3-441f-e093-6d6f-7356e1ff8487@grimberg.me> Date: Mon, 28 Aug 2017 10:00:35 +0300 MIME-Version: 1.0 In-Reply-To: <20170823175815.3646-9-hch@lst.de> Content-Type: text/plain; charset=utf-8; format=flowed List-ID: > This helper allows reinserting a bio into a new queue without much > overhead, but requires all queue limits to be the same for the upper > and lower queues, and it does not provide any recursion preventions, > which requires the caller to not split the bio. Isn't the same limits constraint too restrictive? Say I have two paths to the same namespace via two different HBAs, each with its own virt_boundary capability for example? That would require us to split failover bio wouldn't it? > +/* > + * Fast-path version of generic_make_request. generic_make_request is also called in the fast-path, maybe reword it to: "Fast version of generic_make_request" From mboxrd@z Thu Jan 1 00:00:00 1970 From: sagi@grimberg.me (Sagi Grimberg) Date: Mon, 28 Aug 2017 10:00:35 +0300 Subject: [PATCH 08/10] block: provide a generic_make_request_fast helper In-Reply-To: <20170823175815.3646-9-hch@lst.de> References: <20170823175815.3646-1-hch@lst.de> <20170823175815.3646-9-hch@lst.de> Message-ID: <326ee3b3-441f-e093-6d6f-7356e1ff8487@grimberg.me> > This helper allows reinserting a bio into a new queue without much > overhead, but requires all queue limits to be the same for the upper > and lower queues, and it does not provide any recursion preventions, > which requires the caller to not split the bio. Isn't the same limits constraint too restrictive? Say I have two paths to the same namespace via two different HBAs, each with its own virt_boundary capability for example? That would require us to split failover bio wouldn't it? > +/* > + * Fast-path version of generic_make_request. generic_make_request is also called in the fast-path, maybe reword it to: "Fast version of generic_make_request"