From mboxrd@z Thu Jan 1 00:00:00 1970 Subject: Re: page fault scalability patch V16 [3/4]: Drop page_table_lock in handle_mm_fault From: Nick Piggin In-Reply-To: <1107313778.5131.32.camel@npiggin-nld.site> References: <41E5B7AD.40304@yahoo.com.au> <41E5BC60.3090309@yahoo.com.au> <20050113031807.GA97340@muc.de> <20050113180205.GA17600@muc.de> <20050114043944.GB41559@muc.de> <20050114170140.GB4634@muc.de> <41FF00CE.8060904@yahoo.com.au> <1107304296.5131.13.camel@npiggin-nld.site> <1107308498.5131.28.camel@npiggin-nld.site> <1107313778.5131.32.camel@npiggin-nld.site> Content-Type: text/plain Date: Fri, 04 Feb 2005 17:27:10 +1100 Message-Id: <1107498430.5461.17.camel@npiggin-nld.site> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Christoph Lameter Cc: Andi Kleen , Andrew Morton , torvalds@osdl.org, hugh@veritas.com, linux-mm@kvack.org, linux-ia64@vger.kernel.org, linux-kernel@vger.kernel.org, benh@kernel.crashing.org List-ID: On Wed, 2005-02-02 at 14:09 +1100, Nick Piggin wrote: > On Tue, 2005-02-01 at 18:49 -0800, Christoph Lameter wrote: > > On Wed, 2 Feb 2005, Nick Piggin wrote: > > I mean we could just speculatively copy, risk copying crap and > > discard that later when we find that the pte has changed. This would > > simplify the function: > > > > I think this may be the better approach. Anyone else? > Not to say it is perfect either. Normal semantics say not to touch a page if it is not somehow pinned. So this may cause problems in corner cases (DEBUG_PAGEALLOC comes to mind... hopefully nothing else). But I think a plain read of the page when it isn't pinned is less yucky than writing into the non-pinned struct page. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: aart@kvack.org