From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx198.postini.com [74.125.245.198]) by kanga.kvack.org (Postfix) with SMTP id 5433C6B13F1 for ; Tue, 14 Feb 2012 09:59:54 -0500 (EST) From: Dan Smith Subject: Re: [PATCH] Ensure that walk_page_range()'s start and end are page-aligned References: <1328902796-30389-1-git-send-email-danms@us.ibm.com> <87zkcm23az.fsf@caffeine.danplanet.com> Date: Tue, 14 Feb 2012 06:59:51 -0800 In-Reply-To: (David Rientjes's message of "Mon, 13 Feb 2012 13:55:31 -0800 (PST)") Message-ID: <87pqdh1mvs.fsf@caffeine.danplanet.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: owner-linux-mm@kvack.org List-ID: To: David Rientjes Cc: akpm@linux-foundation.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org DR> That's not a precedent, there's a big difference between the DR> performance of gup_fast(), where we can't spare an additional DR> compare and branch, and walk_page_range(). VM_BUG_ON() is typically DR> used in situations where a debug kernel has been built, including DR> CONFIG_DEBUG_VM, and the check helps to isolate a problem that would DR> be otherwise difficult to find. Okay, fair enough. I was trying to stay in line with the other conventions, knowing that the check would only be done with CONFIG_DEBUG_VM enabled. I'd rather just make it always do the check in walk_page_range(). Does that sound reasonable? -- Dan Smith IBM Linux Technology Center email: danms@us.ibm.com -- 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org