Date: Fri, 26 Jun 2015 09:45:25 -0400
From: Vivek Goyal <vgoyal@redhat.com>
To: Tejun Heo <tj@kernel.org>
Cc: axboe@kernel.dk, linux-kernel@vger.kernel.org, cgroups@vger.kernel.org,
        avanzini.arianna@gmail.com, kernel-team@fb.com
Subject: Re: [PATCH 2/6] blkcg: add blkg_[rw]stat->aux_cnt and replace
 cfq_group->dead_stats with it
Message-ID: <20150626134525.GB14803@redhat.com>
References: <1435268337-1738-1-git-send-email-tj@kernel.org>
 <1435268337-1738-3-git-send-email-tj@kernel.org>
 <20150626132702.GA14803@redhat.com>
 <20150626133540.GA15805@mtj.duckdns.org>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20150626133540.GA15805@mtj.duckdns.org>
User-Agent: Mutt/1.5.23 (2014-03-12)
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 1131
Lines: 28

On Fri, Jun 26, 2015 at 09:35:40AM -0400, Tejun Heo wrote:
> On Fri, Jun 26, 2015 at 09:27:02AM -0400, Vivek Goyal wrote:
> > 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?
> 
> I'm not following.  aux_cnt isn't per-cpu.

I was just curious that why aux_cnt is different from rest of the stats.
(It is atomic64_t while others are not).

Thanks
Vivek
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/