Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030341AbVKRFog (ORCPT ); Fri, 18 Nov 2005 00:44:36 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S964896AbVKRFog (ORCPT ); Fri, 18 Nov 2005 00:44:36 -0500 Received: from smtp104.mail.sc5.yahoo.com ([66.163.169.223]:54938 "HELO smtp104.mail.sc5.yahoo.com") by vger.kernel.org with SMTP id S964891AbVKRFof (ORCPT ); Fri, 18 Nov 2005 00:44:35 -0500 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com.au; h=Received:Message-ID:Date:From:User-Agent:X-Accept-Language:MIME-Version:To:CC:Subject:References:In-Reply-To:Content-Type:Content-Transfer-Encoding; b=3UD/Crr9tG1E3lilBXo6qvJZTH0WQpfNAQSGxKVr9DrzuN4xBu6c8FeQ3nSE3peIRlJ06VJjoXIjYjdH4g8sKTlddW0nw3Xc26HnWPTNrOwcJkroSHGC2MFQ9LfSOPAWDZAX7jvhqBClQ1tafLyHcvTZ/7IdyB6fuvTVnJY3PL4= ; Message-ID: <437D6AD0.5080909@yahoo.com.au> Date: Fri, 18 Nov 2005 16:46:56 +1100 From: Nick Piggin User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7.12) Gecko/20051007 Debian/1.7.12-1 X-Accept-Language: en MIME-Version: 1.0 To: "David S. Miller" CC: hugh@veritas.com, akpm@osdl.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 07/11] unpaged: COW on VM_UNPAGED References: <20051117.155230.25121238.davem@davemloft.net> In-Reply-To: <20051117.155230.25121238.davem@davemloft.net> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1354 Lines: 36 David S. Miller wrote: > From: Hugh Dickins > Date: Thu, 17 Nov 2005 19:37:23 +0000 (GMT) > > >>Remove the BUG_ON(vma->vm_flags & VM_UNPAGED) from do_wp_page, and let >>it do Copy-On-Write without touching the VM_UNPAGED's page counts - but >>this is incomplete, because the anonymous page it inserts will itself >>need to be handled, here and in other functions - next patch. >> >>We still don't copy the page if the pfn is invalid, because the >>copy_user_highpage interface does not allow it. But that's not been >>a problem in the past: can be added in later if the need arises. >> >>Signed-off-by: Hugh Dickins > > > Do we even need this? It is a very serious question... > I think for 2.6.15, yes. We [read: I :(] was too hasty in removing this completely. However I think it would not be unresonable to spit out a warning, and remove it in 2.6.?? Looks like Hugh's done a very good job of this, however keeping complexity down is always a good thing. -- SUSE Labs, Novell Inc. Send instant messages to your online friends http://au.messenger.yahoo.com - 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/