From mboxrd@z Thu Jan 1 00:00:00 1970 Subject: Re: Prezeroing V2 [0/3]: Why and When it works From: Arjan van de Ven In-Reply-To: References: <41C20E3E.3070209@yahoo.com.au> Content-Type: text/plain Date: Thu, 23 Dec 2004 20:49:13 +0100 Message-Id: <1103831353.4139.16.camel@laptopd505.fenrus.org> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Christoph Lameter Cc: akpm@osdl.org, linux-ia64@vger.kernel.org, torvalds@osdl.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org List-ID: > The most expensive operation in the page fault handler is (apart of SMP > locking overhead) the zeroing of the page. This zeroing means that all > cachelines of the faulted page (on Altix that means all 128 cachelines of > 128 byte each) must be loaded and later written back. This patch allows to > avoid having to load all cachelines if only a part of the cachelines of > that page is needed immediately after the fault. eh why will all cachelines be loaded? Surely you can avoid the write- allocate behavior for this case..... -- 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