From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Mon, 16 Jan 2006 07:47:50 -0800 (PST) From: Christoph Lameter Subject: Re: Race in new page migration code? In-Reply-To: Message-ID: References: <20060114155517.GA30543@wotan.suse.de> <20060114181949.GA27382@wotan.suse.de> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org Return-Path: To: Hugh Dickins Cc: Nick Piggin , Andrew Morton , Linux Kernel Mailing List , Linux Memory Management List List-ID: On Mon, 16 Jan 2006, Hugh Dickins wrote: > Indeed they are, at present and quite likely into posterity. But > they're not a common case here, and migrate_page_add now handles them > silently, so why bother to complicate it with an unnecessary check? check_range also is used for statistics and for checking if a range is policy compliant. Without that check zeropages may be counted or flagged as not on the right node with MPOL_MF_STRICT. For migrate_page_add this has now simply become an optimization since there is no WARN_ON occurring anymore. > Or have you found the zero page mapcount distorting get_stats stats? > If that's an issue, then better add a commented test for it there. It also applies to the policy compliance check. > Hmm, that battery of unusual tests at the start of migrate_page_add > is odd: the tests don't quite match the comment, and it isn't clear > what reasoning lies behind the comment anywa Hmm.... Maybe better clean up the thing a bit. Will do that when I get back to work next week. -- 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