From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Subject: Re: [PATCH] block: kyber: make kyber more friendly with merging To: Ming Lei Cc: Omar Sandoval , Jens Axboe , linux-block , Linux Kernel Mailing List References: <1527000509-2619-1-git-send-email-jianchao.w.wang@oracle.com> <20180522200214.GF9536@vader> From: "jianchao.wang" Message-ID: Date: Wed, 30 May 2018 16:36:32 +0800 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 List-ID: Hi ming Thanks for your kindly response. On 05/30/2018 04:22 PM, Ming Lei wrote: >>> you could keep the software queues as-is but add our own version of >>> flush_busy_ctxs() that only removes requests of the domain that we want. >>> If one domain gets backed up, that might get messy with long iterations, >>> though. >> Yes, I also considered this approach :) >> But the long iterations on every ctx->rq_list looks really inefficient. > Right, this list can be quite long if dispatch token is used up. > > You might try to introduce per-domain list into ctx directly, then 'none' > may benefit from this change too since bio merge should be done > on the per-domain list actually. Yes, it maybe good for merging of 'none', because the rq_list is split into 3 lists, and not need to iterate the whole rq_list any more. But what's about the dispatch when there is no io scheduler. We will dispatch request from ctx one by one at the moment. If we have per-domain list in ctx, we have to introduce some policies to determine which domain to dispatch, and these policies should be in io scheduler actually. Thanks Jianchao