Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760620AbXEPEwZ (ORCPT ); Wed, 16 May 2007 00:52:25 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754419AbXEPEwS (ORCPT ); Wed, 16 May 2007 00:52:18 -0400 Received: from smtp109.mail.mud.yahoo.com ([209.191.85.219]:37465 "HELO smtp109.mail.mud.yahoo.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1752151AbXEPEwS (ORCPT ); Wed, 16 May 2007 00:52:18 -0400 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com.au; h=Received:X-YMail-OSG:Message-ID:Date:From:User-Agent:X-Accept-Language:MIME-Version:To:CC:Subject:References:In-Reply-To:Content-Type:Content-Transfer-Encoding; b=AwJ39IKVqkMTOF8+iq+gwr6Y4l3mz15SkVC09NFKtNnN+WvciafcmQ81+KZr8k62fj0HbI2qK79CTYnuSm2SE/DfdHK5nzZkz5Ls9/vo3rVSyktSxmP8dAc2AByfwSkagKN4fwjuZFF4Flqt2uJcGrxsBOKRSlhYc+fvRgh8Mgc= ; X-YMail-OSG: 4X9pgc8VM1n1qwxgitNNGNWFuA.kTestpFENfYC8yEKkEJpKkOCc2_zbjKnYVWGuen01xXwhCQ-- Message-ID: <464A8DF5.2010903@yahoo.com.au> Date: Wed, 16 May 2007 14:52:05 +1000 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: Christoph Lameter CC: Andrew Morton , linux-kernel@vger.kernel.org, Satyam Sharma , Nate Diller Subject: Re: Pagecache zeroing: zero_user_segment, zero_user_segments and zero_user References: <20070515202442.eeaa49a0.akpm@linux-foundation.org> In-Reply-To: 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: 1060 Lines: 28 Christoph Lameter wrote: > On Tue, 15 May 2007, Andrew Morton wrote: > > >>> The functions above default to KM_USER0 which is also always used when >>> zero_user_page was called except in one single case. We open code that >>> single case to draw attention to the spot. >>> >> >>Dunno. fwiw, we decided to _not_ embed KM_USER0 in the callee: we have had >>some pretty ghastly bugs in the past due to misuse of kmap slots so the >>idea was to shove the decision into the caller's face, make them think >>about what they're doing > > > On the other hand non highmem platforms are burdened with always repeating > the same KM_USER0 in every function call. Isnt it enough to know that > standard functions use KM_USER0 for their operations? Couldn't that be filtered out inline? -- SUSE Labs, Novell Inc. - 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/