Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753821AbXECWle (ORCPT ); Thu, 3 May 2007 18:41:34 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754434AbXECWle (ORCPT ); Thu, 3 May 2007 18:41:34 -0400 Received: from extu-mxob-1.symantec.com ([216.10.194.28]:52469 "EHLO extu-mxob-1.symantec.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753821AbXECWld (ORCPT ); Thu, 3 May 2007 18:41:33 -0400 Date: Thu, 3 May 2007 23:41:15 +0100 (BST) From: Hugh Dickins X-X-Sender: hugh@blonde.wat.veritas.com To: Christoph Lameter cc: Andrew Morton , Paul Mackerras , Benjamin Herrenschmidt , linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: Re: 2.6.22 -mm merge plans: slub on PowerPC In-Reply-To: Message-ID: References: <20070430162007.ad46e153.akpm@linux-foundation.org> <20070501125559.9ab42896.akpm@linux-foundation.org> <20070503011515.0d89082b.akpm@linux-foundation.org> <20070503015729.7496edff.akpm@linux-foundation.org> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-OriginalArrivalTime: 03 May 2007 22:41:30.0046 (UTC) FILETIME=[31254DE0:01C78DD4] X-Brightmail-Verdict: VlJEQwAAAAIAAAABAAAAAAAAAAEAAAAAAAAABmluYm94AHBhdWx1c0BzYW1iYS5vcmcAbGludXgta2VybmVsQHZnZXIua2VybmVsLm9yZwBha3BtQGxpbnV4LWZvdW5kYXRpb24ub3JnAGJlbmhAa2VybmVsLmNyYXNoaW5nLm9yZwBjbGFtZXRlckBzZ2kuY29tAGxpbnV4LW1tQGt2YWNrLm9yZwA= X-Brightmail-Tracker: AAAAAA== Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1387 Lines: 30 On Thu, 3 May 2007, Christoph Lameter wrote: > > There are SLUB patches pending (not in rc7-mm2 as far as I can recall) > that reduce the default page order sizes to head off this issue. The > defaults were initially too large (and they still default to large > for testing if Mel's Antifrag work is detected to be active). Sounds good. > > - return kmem_cache_alloc(pgtable_cache[PTE_CACHE_NUM], > > - GFP_KERNEL|__GFP_REPEAT); > > + return quicklist_alloc(0, GFP_KERNEL|__GFP_REPEAT, NULL); > > __GFP_REPEAT is unusual here but this was carried over from the > kmem_cache_alloc it seems. Hmm... There is some variance on how we do this > between arches. Should we uniformly set or not set this flag? Not something to get into in this patch, but it did surprise me too. I believe __GFP_REPEAT should be avoided, and I don't see justification for it here (but need to remember not to do a blind virt_to_page on the result in some places if it might return NULL - which IIRC it actually can do even if __GFP_REPEAT, when chosen for OOM kill). But I've a suspicion it got put in there for some good reason I don't know about. Hugh - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/