linux-mm.kvack.org archive mirror
 help / color / mirror / Atom feed
From: "Kirill A. Shutemov" <kirill@shutemov.name>
To: Bob Liu <lliubbo@gmail.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
	Andrea Arcangeli <aarcange@redhat.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	Rik van Riel <riel@redhat.com>, Mel Gorman <mgorman@suse.de>,
	Michel Lespinasse <walken@google.com>,
	Sasha Levin <sasha.levin@oracle.com>,
	Dave Jones <davej@redhat.com>, Vlastimil Babka <vbabka@suse.cz>,
	Linux-MM <linux-mm@kvack.org>,
	Linux-Kernel <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] thp: close race between split and zap huge pages
Date: Wed, 16 Apr 2014 11:42:36 +0300	[thread overview]
Message-ID: <20140416084236.GA23247@node.dhcp.inet.fi> (raw)
In-Reply-To: <CAA_GA1ecVD2GuxvPqBhGKdUfMeBJU+m-i5XeSzMmDXy=QncLqA@mail.gmail.com>

On Wed, Apr 16, 2014 at 07:52:29AM +0800, Bob Liu wrote:
> >         *ptl = pmd_lock(mm, pmd);
> > -       if (pmd_none(*pmd))
> > +       if (!pmd_present(*pmd))
> >                 goto unlock;
> 
> But I didn't get the idea why pmd_none() was removed?

!pmd_present(*pmd) is weaker check then pmd_none(*pmd). I mean if
pmd_none(*pmd) is true then pmd_present(*pmd) is always false.
Correct me if I'm wrong.

-- 
 Kirill A. Shutemov

  reply	other threads:[~2014-04-16  8:42 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-04-15 21:48 [PATCH] thp: close race between split and zap huge pages Kirill A. Shutemov
2014-04-15 23:52 ` Bob Liu
2014-04-16  8:42   ` Kirill A. Shutemov [this message]
2014-04-17  0:28     ` Bob Liu
2014-04-17 20:16 ` Andrea Arcangeli
  -- strict thread matches above, loose matches on Subject: below --
2014-04-15 21:48 Kirill A. Shutemov
2014-04-16 14:46 ` Sasha Levin
2014-04-16 20:19 ` Andrew Morton
2014-04-18 20:56   ` Kirill A. Shutemov

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20140416084236.GA23247@node.dhcp.inet.fi \
    --to=kirill@shutemov.name \
    --cc=aarcange@redhat.com \
    --cc=akpm@linux-foundation.org \
    --cc=davej@redhat.com \
    --cc=kirill.shutemov@linux.intel.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=lliubbo@gmail.com \
    --cc=mgorman@suse.de \
    --cc=riel@redhat.com \
    --cc=sasha.levin@oracle.com \
    --cc=vbabka@suse.cz \
    --cc=walken@google.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).