From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Subject: Re: [PATCH V7 4/6] blk-mq: introduce .get_budget and .put_budget in blk_mq_ops To: Bart Van Assche , "ming.lei@redhat.com" Cc: "linux-kernel@vger.kernel.org" , "linux-block@vger.kernel.org" , "hch@infradead.org" , "tom81094@gmail.com" , "paolo.valente@linaro.org" , "linux-scsi@vger.kernel.org" , "oleksandr@natalenko.name" , "john.garry@huawei.com" , "osandov@fb.com" , "loberman@redhat.com" References: <20171012183704.22326-1-ming.lei@redhat.com> <20171012183704.22326-5-ming.lei@redhat.com> <9a741c03-90a3-e583-ddde-0ed71c8570a2@kernel.dk> <20171013001919.GA24715@ming.t460p> <6efdb459-8746-562d-06dc-5b3e172076e1@kernel.dk> <20171013160731.GA30899@ming.t460p> <1507912260.13345.0.camel@wdc.com> From: Jens Axboe Message-ID: Date: Fri, 13 Oct 2017 10:33:40 -0600 MIME-Version: 1.0 In-Reply-To: <1507912260.13345.0.camel@wdc.com> Content-Type: text/plain; charset=utf-8 List-ID: On 10/13/2017 10:31 AM, Bart Van Assche wrote: > On Sat, 2017-10-14 at 00:07 +0800, Ming Lei wrote: >> Actually it is in hot path, for example, lpfc and qla2xx's queue depth is 3, > > Sorry but I doubt whether that is correct. More in general, I don't know any modern > storage HBA for which the default queue depth is so low. That does seem insanely low. BTW, even a low depth isn't an issue, as long as we know what it roughly is. -- Jens Axboe