From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dave Hansen Subject: Re: [patch 3/9] Guest page hinting: volatile page cache. Date: Fri, 01 Sep 2006 08:37:54 -0700 Message-ID: <1157125074.28577.94.camel@localhost.localdomain> References: <20060901110948.GD15684@skybase> <1157122479.28577.64.camel@localhost.localdomain> <1157124580.21733.10.camel@localhost> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1157124580.21733.10.camel@localhost> Sender: linux-kernel-owner@vger.kernel.org To: schwidefsky@de.ibm.com Cc: linux-kernel@vger.kernel.org, virtualization@lists.osdl.org, akpm@osdl.org, nickpiggin@yahoo.com.au, frankeh@watson.ibm.com, rhim@cc.gateh.edu List-Id: virtualization@lists.linuxfoundation.org On Fri, 2006-09-01 at 17:29 +0200, Martin Schwidefsky wrote: > On Fri, 2006-09-01 at 07:54 -0700, Dave Hansen wrote: > > Are all of the un/likely()s in here really needed? > > Well, no un/likely is really needed. But they do help the compiler to > generate better code. It IS unlikely that a page is discarded. I know what they're _for_. ;) I seem to recall people being poked in the past for sprinkling too many of these things around their code. I just wanted to make sure that there was some tangible reason for doing it, other than speculative performance optimization. -- Dave