From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750855AbWFXQGg (ORCPT ); Sat, 24 Jun 2006 12:06:36 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750857AbWFXQGg (ORCPT ); Sat, 24 Jun 2006 12:06:36 -0400 Received: from smtp108.mail.mud.yahoo.com ([209.191.85.218]:6736 "HELO smtp108.mail.mud.yahoo.com") by vger.kernel.org with SMTP id S1750854AbWFXQGf (ORCPT ); Sat, 24 Jun 2006 12:06:35 -0400 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com.au; h=Received:Message-ID:Date:From:User-Agent:X-Accept-Language:MIME-Version:To:CC:Subject:References:In-Reply-To:Content-Type:Content-Transfer-Encoding; b=iB4HbzX1PSFYwesy4xCtQ+brHCDWTTerJPYCWoPzfgfSgb/sQPNnKXj7QVAouF5UdPA0oFBV70aZ26Pc42eG8YuZCQdjTs4xcT7OIqnEF6d4GbEXojMYC69UrKzSPj7OP9dqnOUKZDROeSBfmhRdY3xdEMm45i3sf3Yo+yykb9M= ; Message-ID: <449D6305.4060303@yahoo.com.au> Date: Sun, 25 Jun 2006 02:06:29 +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: Arjan van de Ven CC: Steven Rostedt , Andrew Morton , Jeff Garzik , linux-kernel@vger.kernel.org, torvalds@osdl.org Subject: Re: [PATCH] ext3_clear_inode(): avoid kfree(NULL) References: <200606231502.k5NF2jfO007109@hera.kernel.org> <449C3817.2030802@garzik.org> <20060623142430.333dd666.akpm@osdl.org> <1151151104.3181.30.camel@laptopd505.fenrus.org> <1151152059.3181.37.camel@laptopd505.fenrus.org> <1151153177.3181.39.camel@laptopd505.fenrus.org> <1151153635.3181.41.camel@laptopd505.fenrus.org> <1151158295.3181.46.camel@laptopd505.fenrus.org> In-Reply-To: <1151158295.3181.46.camel@laptopd505.fenrus.org> 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 Arjan van de Ven wrote: >>The jne is expected to fail, so we will always continue to 0x13. Now is >>this a problem with x86/x86_64? > > > I'm not saying there is a problem; likely/unlikely do have an effect for > sure, it's just not a "make it free" thing.... On x86 I think the main saving is the icache one. However I guess gcc would try to align with the branch prediction behaviour for unknown branches too. The microoptimisation is that the call avoids the unlikely branch in kfree. Maybe for x86 this isn't going to matter, but for some architectures in might. -- SUSE Labs, Novell Inc. Send instant messages to your online friends http://au.messenger.yahoo.com