Date: Thu, 9 Jul 2009 12:24:28 +0900
From: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
To: linux-mm@kvack.org
Cc: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
       npiggin@suse.de,
       "hugh.dickins@tiscali.co.uk" <hugh.dickins@tiscali.co.uk>,
       avi@redhat.com, "akpm@linux-foundation.org" <akpm@linux-foundation.org>,
       torvalds@linux-foundation.org, aarcange@redhat.com
Subject: [PATCH 0/2] ZERO PAGE again v3.
Message-Id: <20090709122428.8c2d4232.kamezawa.hiroyu@jp.fujitsu.com>
Organization: FUJITSU Co. LTD.
Mime-Version: 1.0
Content-Type: text/plain; charset=US-ASCII
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 916
Lines: 25

After v2 discussion, I felt that "Go" sign can be given if implemetaion is neat
and tiny and overhead seems very small. Here is v3.

In this version,

 - use pte_special() in vm_normal_page()
   All ZERO_PAGE check will go down to vm_normal_page() and check is done here.
   Some new flags in follow_page() and get_user_pages().

 - per arch use-zero-page config is added.
   IIUC, archs which have _PAGE_SPECIAL is only x86, powerpc, s390.
   Because this patch make use of pte_special() check, config to use zero page
   is added and you can turn it off if necessary.
   I this patch, only x86 is turned on which I can test.

Any comments are welcome. 

Thanks,
-Kame

--
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/