From mboxrd@z Thu Jan 1 00:00:00 1970 Subject: Re: [PATCH 0/7] blk-mq: fix queue quiescing To: Bart Van Assche , "ming.lei@redhat.com" Cc: "hch@infradead.org" , "linux-block@vger.kernel.org" References: <20170525042131.13172-1-ming.lei@redhat.com> <1495689892.3045.2.camel@sandisk.com> <20170525090917.GB15737@ming.t460p> <1495733047.2615.1.camel@sandisk.com> From: Jens Axboe Message-ID: Date: Thu, 25 May 2017 11:31:30 -0600 MIME-Version: 1.0 In-Reply-To: <1495733047.2615.1.camel@sandisk.com> Content-Type: text/plain; charset=utf-8 List-ID: On 05/25/2017 11:24 AM, Bart Van Assche wrote: > On Thu, 2017-05-25 at 17:09 +0800, Ming Lei wrote: >> Another big issue is that 'srcu_struct' is very big, which shouldn't >> be embedded into hctx, since we only have one real user of >> BLK_MQ_F_BLOCKING. >> >> So I will fix that too. > > Hello Ming, > > Is something like the (untested) patch below perhaps what you had in mind? > > Subject: [PATCH] blk-mq: Reduce blk_mq_hw_ctx size > > Since the srcu structure is rather large (184 bytes on an x86-64 > system), only allocate it if needed. On my normal laptop setup, it's actually 408 bytes (!!). -- Jens Axboe