From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail202.messagelabs.com (mail202.messagelabs.com [216.82.254.227]) by kanga.kvack.org (Postfix) with ESMTP id B04526B004F for ; Thu, 5 Feb 2009 13:54:53 -0500 (EST) Message-ID: <498B35F9.601@goop.org> Date: Thu, 05 Feb 2009 10:54:49 -0800 From: Jeremy Fitzhardinge MIME-Version: 1.0 Subject: Re: pud_bad vs pud_bad References: <498B2EBC.60700@goop.org> <20090205184355.GF5661@elte.hu> In-Reply-To: <20090205184355.GF5661@elte.hu> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org To: Ingo Molnar Cc: William Lee Irwin III , Linux Kernel Mailing List , Linux Memory Management List List-ID: Ingo Molnar wrote: > * Jeremy Fitzhardinge wrote: > > >> I'm looking at unifying the 32 and 64-bit versions of pud_bad. >> >> 32-bits defines it as: >> >> static inline int pud_bad(pud_t pud) >> { >> return (pud_val(pud) & ~(PTE_PFN_MASK | _KERNPG_TABLE | _PAGE_USER)) != 0; >> } >> >> and 64 as: >> >> static inline int pud_bad(pud_t pud) >> { >> return (pud_val(pud) & ~(PTE_PFN_MASK | _PAGE_USER)) != _KERNPG_TABLE; >> } >> >> >> I'm inclined to go with the 64-bit version, but I'm wondering if there's >> something subtle I'm missing here. >> > > Why go with the 64-bit version? The 32-bit check looks more compact and > should result in smaller code. > Well, its stricter. But I don't really understand what condition its actually testing for. J -- 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