From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qk0-f197.google.com (mail-qk0-f197.google.com [209.85.220.197]) by kanga.kvack.org (Postfix) with ESMTP id 9FFF46B02C3 for ; Wed, 31 May 2017 10:08:38 -0400 (EDT) Received: by mail-qk0-f197.google.com with SMTP id w131so5838449qka.5 for ; Wed, 31 May 2017 07:08:38 -0700 (PDT) Received: from resqmta-ch2-01v.sys.comcast.net (resqmta-ch2-01v.sys.comcast.net. [2001:558:fe21:29:69:252:207:33]) by mx.google.com with ESMTPS id t18si15818551qta.84.2017.05.31.07.08.37 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 31 May 2017 07:08:37 -0700 (PDT) Date: Wed, 31 May 2017 09:06:03 -0500 (CDT) From: Christoph Lameter Subject: Re: 4.12-rc ppc64 4k-page needs costly allocations In-Reply-To: Message-ID: References: Content-Type: text/plain; charset=US-ASCII Sender: owner-linux-mm@kvack.org List-ID: To: Hugh Dickins Cc: "Aneesh Kumar K.V" , Michael Ellerman , linuxppc-dev@lists.ozlabs.org, linux-mm@kvack.org On Tue, 30 May 2017, Hugh Dickins wrote: > I wanted to try removing CONFIG_SLUB_DEBUG, but didn't succeed in that: > it seemed to be a hard requirement for something, but I didn't find what. CONFIG_SLUB_DEBUG does not enable debugging. It only includes the code to be able to enable it at runtime. > I did try CONFIG_SLAB=y instead of SLUB: that lowers these allocations to > the expected order:3, which then results in OOM-killing rather than direct > allocation failure, because of the PAGE_ALLOC_COSTLY_ORDER 3 cutoff. But > makes no real difference to the outcome: swapping loads still abort early. SLAB uses order 3 and SLUB order 4??? That needs to be tracked down. Why are the slab allocators used to create slab caches for large object sizes? > Relying on order:3 or order:4 allocations is just too optimistic: ppc64 > with 4k pages would do better not to expect to support a 128TB userspace. I thought you had these huge 64k page sizes? -- 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