From: "Kani, Toshimitsu" <toshi.kani@hpe.com>
To: "david@fromorbit.com" <david@fromorbit.com>
CC: "dan.j.williams@intel.com" <dan.j.williams@intel.com>,
        "viro@zeniv.linux.org.uk" <viro@zeniv.linux.org.uk>,
        "ross.zwisler@linux.intel.com" <ross.zwisler@linux.intel.com>,
        "linux-nvdimm@lists.01.org" <linux-nvdimm@ml01.01.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "akpm@linux-foundation.org" <akpm@linux-foundation.org>,
        "linux-fsdevel@vger.kernel.org" <linux-fsdevel@vger.kernel.org>
Subject: Re: [PATCH] DAX: enable iostat for read/write
Thread-Topic: [PATCH] DAX: enable iostat for read/write
Thread-Index: AQHSJkAwV6IPkv81+E6hHqMOpambIaCpJkaAgAPH/AA=
Date: Mon, 17 Oct 2016 17:40:56 +0000
Message-ID: <1476725956.20881.68.camel@hpe.com>
References: <1476465913-25305-1-git-send-email-toshi.kani@hpe.com>
         <20161015075443.GG27872@dastard>
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On Sat, 2016-10-15 at 18:54 +1100, Dave Chinner wrote:
> On Fri, Oct 14, 2016 at 11:25:13AM -0600, Toshi Kani wrote:
 :
> > +static void dax_iostat_start(struct gendisk *disk, struct iov_iter
> > *iter,
> > +			     unsigned long *start)
> > +{
> > +	int rw = iov_iter_rw(iter);
> > +	int sec = iov_iter_count(iter) >> 9;
> > +	int cpu = part_stat_lock();
> > +
> > +	*start = jiffies;
> > +	part_round_stats(cpu, &disk->part0);
> > +	part_stat_inc(cpu, &disk->part0, ios[rw]);
> > +	part_stat_add(cpu, &disk->part0, sectors[rw], sec);
> > +	part_inc_in_flight(&disk->part0, rw);
> > +	part_stat_unlock();
> > +}
> 
> Why reimplement generic_start_io_acct() and generic_end_io_acct()?

It was modeled after __nd_iostat_start() / nd_iostart_end().  I agree
that we can use generic_start_io_acct() and generic_end_io_acct() here.

Should we also change the nd interface to use the generic version as
well?

Thanks,
-Toshi

ps.
Sorry I realized this comment after sending out v2...