Date: Thu, 10 Feb 2011 19:09:24 +0100
From: Andrea Arcangeli <aarcange@redhat.com>
To: Mel Gorman <mel@csn.ul.ie>
Cc: Dave Hansen <dave@linux.vnet.ibm.com>, linux-kernel@vger.kernel.org,
        linux-mm@kvack.org, Michael J Wolf <mjwolf@us.ibm.com>,
        Johannes Weiner <hannes@cmpxchg.org>,
        David Rientjes <rientjes@google.com>
Subject: Re: [PATCH 5/5] have smaps show transparent huge pages
Message-ID: <20110210180924.GB3347@random.random>
References: <20110209195406.B9F23C9F@kernel>
 <20110209195413.6D3CB37F@kernel>
 <20110210112032.GG17873@csn.ul.ie>
 <1297350115.6737.14208.camel@nimitz>
 <20110210150942.GL17873@csn.ul.ie>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20110210150942.GL17873@csn.ul.ie>
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 1486
Lines: 35

On Thu, Feb 10, 2011 at 03:09:42PM +0000, Mel Gorman wrote:
> On Thu, Feb 10, 2011 at 07:01:55AM -0800, Dave Hansen wrote:
> > On Thu, 2011-02-10 at 11:20 +0000, Mel Gorman wrote:
> > > > @@ -394,6 +395,7 @@ static int smaps_pte_range(pmd_t *pmd, u
> > > >                       spin_lock(&walk->mm->page_table_lock);
> > > >               } else {
> > > >                       smaps_pte_entry(*(pte_t *)pmd, addr, HPAGE_SIZE, walk);
> > > > +                     mss->anonymous_thp += HPAGE_SIZE;
> > > 
> > > I should have thought of this for the previous patch but should this be
> > > HPAGE_PMD_SIZE instead of HPAGE_SIZE? Right now, they are the same value
> > > but they are not the same thing.
> > 
> > Probably.  There's also a nice BUG() in HPAGE_PMD_SIZE if the THP config
> > option is off, which is an added bonus.
> > 
> 
> Unless Andrea has an objection, I'd prefer to see HPAGE_PMD_SIZE.

We get there only through pmd_trans_huge, so HPAGE_PMD_SIZE is
certainly more correct, agreed.

I also think this can go in -mm after s/HPAGE_SIZE/HPAGE_PMD_SIZE/ and
after correcting the locking (see other email).

Maybe it'd be cleaner if we didn't need to cast the pmd to pte_t but I
guess this makes things simpler.

Thanks!
Andrea
--
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/