From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Wed, 9 May 2007 00:35:18 +0200 From: Nick Piggin Subject: Re: [rfc] optimise unlock_page Message-ID: <20070508223518.GC20174@wotan.suse.de> References: <20070508114003.GB19294@wotan.suse.de> <20070508113709.GA19294@wotan.suse.de> <9948.1178626415@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <9948.1178626415@redhat.com> Sender: owner-linux-mm@kvack.org Return-Path: To: David Howells Cc: linux-arch@vger.kernel.org, Benjamin Herrenschmidt , Andrew Morton , Linux Kernel Mailing List , Linux Memory Management List List-ID: On Tue, May 08, 2007 at 01:13:35PM +0100, David Howells wrote: > > Nick Piggin wrote: > > > This patch trades a page flag for a significant improvement in the unlock_page > > fastpath. Various problems in the previous version were spotted by Hugh and > > Ben (and fixed in this one). > > It looks reasonable at first glance, though it does consume yet another page > flag:-/ However, I think that's probably a worthy trade. Well, that's the big question :) > > } > > - > > + > > +static inline void unlock_page(struct page *page) > > +{ > > + VM_BUG_ON(!PageLocked(page)); > > + ClearPageLocked_Unlock(page); > > + if (unlikely(PageWaiters(page))) > > + __unlock_page(page); > > +} > > + > > Please don't simply discard the documentation, we have little enough as it is: Oops, right. -- 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: email@kvack.org