From: Vivek Goyal Subject: Re: [PATCH 2/6] blkcg: add blkg_[rw]stat->aux_cnt and replace cfq_group->dead_stats with it Date: Fri, 26 Jun 2015 09:27:02 -0400 Message-ID: <20150626132702.GA14803@redhat.com> References: <1435268337-1738-1-git-send-email-tj@kernel.org> <1435268337-1738-3-git-send-email-tj@kernel.org> Mime-Version: 1.0 Return-path: Content-Disposition: inline In-Reply-To: <1435268337-1738-3-git-send-email-tj-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org> Sender: cgroups-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Tejun Heo Cc: axboe-tSWWG44O7X1aa/9Udqfwiw@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, avanzini.arianna-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, kernel-team-b10kYP2dOMg@public.gmane.org On Thu, Jun 25, 2015 at 05:38:53PM -0400, Tejun Heo wrote: [..] > It's planned that the core stats will be moved to blkcg_gq, so we want > to move the mechanism for keeping track of the stats of dead children > from cfq to blkcg core. This patch adds blkg_[rw]stat->aux_cnt which > are atomic64_t's keeping track of auxiliary counts which are excluded > when reading local counts but included for recursive. Hi Tejun, So aux_cnt is atomic64_t as updation is not the hot path hence there is not much value in keeping it as per cpu? Thanks Vivek