From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Bart Van Assche To: "ming.lei@redhat.com" CC: "linux-kernel@vger.kernel.org" , "linux-block@vger.kernel.org" , "jianchao.w.wang@oracle.com" , "axboe@kernel.dk" Subject: Re: [RFC] blk-mq: clean up the hctx restart Date: Thu, 2 Aug 2018 17:24:15 +0000 Message-ID: <4868e0b82ac6e87aede7fc52da67d3a7913d680b.camel@wdc.com> References: <1533009735-2221-1-git-send-email-jianchao.w.wang@oracle.com> <20180731045805.GE15701@ming.t460p> <8a3383e6-2926-6858-d8f2-671f3cb9e460@oracle.com> <20180731061616.GF15701@ming.t460p> <42371198-2a4b-1062-3564-411645ffba98@oracle.com> <20180801085841.GA27962@ming.t460p> <9feaa41702ef6fcc00ce1b8aa19bbe179edf4e3f.camel@wdc.com> <20180802165831.GB8928@ming.t460p> <7c933e7e60831f985297d8cc5a540171fc921f44.camel@wdc.com> <20180802171723.GD8928@ming.t460p> In-Reply-To: <20180802171723.GD8928@ming.t460p> Content-Type: text/plain; charset="utf-7" MIME-Version: 1.0 List-ID: On Fri, 2018-08-03 at 01:17 +-0800, Ming Lei wrote: +AD4- Not mentioning big CPU utilization is consumed unnecessarily for iter= ating +AD4- over all queues even though there is only one active queue, is this f= air from +AD4- system view? I hope that someone will come up some day with a better solution than the list+AF8-for+AF8-each+AF8-entry+AF8-rcu+AF8-rr() loop. But as long as such = a solution has not yet been found that loop should stay in order to preserve fair handling of larg= e numbers of LUNs. Bart.