Re: [PATCH v4 RESEND 0/2] Align mmap address for DAX pmd mappings

From: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
To: "Kani, Toshimitsu" <toshi.kani@hpe.com>
Cc: "kirill@shutemov.name" <kirill@shutemov.name>,
	"hughd@google.com" <hughd@google.com>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"linux-mm@kvack.org" <linux-mm@kvack.org>,
	"adilger.kernel@dilger.ca" <adilger.kernel@dilger.ca>,
	"mike.kravetz@oracle.com" <mike.kravetz@oracle.com>,
	"dan.j.williams@intel.com" <dan.j.williams@intel.com>,
	"mawilcox@microsoft.com" <mawilcox@microsoft.com>,
	"akpm@linux-foundation.org" <akpm@linux-foundation.org>,
	"linux-nvdimm@lists.01.org" <linux-nvdimm@ml01.01.org>,
	"linux-fsdevel@vger.kernel.org" <linux-fsdevel@vger.kernel.org>,
	"ross.zwisler@linux.intel.com" <ross.zwisler@linux.intel.com>,
	"tytso@mit.edu" <tytso@mit.edu>,
	"david@fromorbit.com" <david@fromorbit.com>,
	"jack@suse.cz" <jack@suse.cz>
Subject: Re: [PATCH v4 RESEND 0/2] Align mmap address for DAX pmd mappings
Date: Fri, 9 Sep 2016 15:36:08 +0300	[thread overview]
Message-ID: <20160909123608.GA75965@black.fi.intel.com> (raw)
In-Reply-To: <1473376846.2092.69.camel@hpe.com>

On Thu, Sep 08, 2016 at 11:21:46PM +0000, Kani, Toshimitsu wrote:
> On Thu, 2016-09-08 at 07:48 -0600, Kani, Toshimitsu wrote:
> > On Thu, 2016-09-08 at 13:57 +0300, Kirill A. Shutemov wrote:
> > > 
> > > On Mon, Aug 29, 2016 at 10:00:43PM +0000, Kani, Toshimitsu wrote:
>  :
> > > > 
> > > > Looking further, these shmem_huge handlings only check pre-
> > > > conditions.  So, we should be able to make shmem_get_unmapped_are
> > > > a() as a wrapper, which checks such shmem-specific conitions, and
> > > > then call __thp_get_unmapped_area() for the actual work.  All
> > > > DAX-specific checks are performed in thp_get_unmapped_area() as
> > > > well.  We can make  __thp_get_unmapped_area() as a common
> > > > function.
> > > > 
> > > > I'd prefer to make such change as a separate item,
> > > 
> > > Do you have plan to submit such change?
> > 
> > Yes, I will submit the change once I finish testing.
> 
> I found a bug in the current code, and need some clarification.  The
> if-statement below is reverted.

<two-hands-facepalm>

Yeah. It was repored by Hillf[1]. The fixup got lost. :(

Could you post a proper patch with the fix?

I would be nice to credit Hillf there too.

[1] http://lkml.kernel.org/r/054f01d1c86f$2994d5c0$7cbe8140$@alibaba-inc.com

-- 
 Kirill A. Shutemov