From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-1.0 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 577A3C43142 for ; Thu, 2 Aug 2018 14:23:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0DF132088E for ; Thu, 2 Aug 2018 14:23:38 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=amazonses.com header.i=@amazonses.com header.b="H0B2ETwb" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0DF132088E Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387549AbeHBQPB (ORCPT ); Thu, 2 Aug 2018 12:15:01 -0400 Received: from a9-99.smtp-out.amazonses.com ([54.240.9.99]:45974 "EHLO a9-99.smtp-out.amazonses.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387504AbeHBQPA (ORCPT ); Thu, 2 Aug 2018 12:15:00 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/simple; s=ug7nbtf4gccmlpwj322ax3p6ow6yfsug; d=amazonses.com; t=1533219814; h=Date:From:To:cc:Subject:In-Reply-To:Message-ID:References:MIME-Version:Content-Type:Feedback-ID; bh=y6bulpRbEjfHIFhEoTfMdi3LypqJNGhWx4XpQySka6E=; b=H0B2ETwbICTy/Zab4/DHdxumCbtnMTuqzwHCV8TcPTgkSJBlmM0tvoZ8vyYwj5nE kbWITil3eplsvNJYeLFM2yV/d7Cbuq6I2zI1nUKra5mvvs0RkXIHWcZa5YtZd6B4ufB VgvK5ctPnOV0pJrrB6B9JjEhusWxocPmfQRj8j5U= Date: Thu, 2 Aug 2018 14:23:34 +0000 From: Christopher Lameter X-X-Sender: cl@nuc-kabylake To: Jeremy Linton cc: linux-mm@kvack.org, penberg@kernel.org, rientjes@google.com, iamjoonsoo.kim@lge.com, akpm@linux-foundation.org, mhocko@suse.com, vbabka@suse.cz, Punit.Agrawal@arm.com, Lorenzo.Pieralisi@arm.com, linux-arm-kernel@lists.infradead.org, bhelgaas@google.com, linux-kernel@vger.kernel.org Subject: Re: [RFC 1/2] slub: Avoid trying to allocate memory on offline nodes In-Reply-To: <20180801200418.1325826-2-jeremy.linton@arm.com> Message-ID: <01000164fb05bba7-1804e794-a08d-4ee0-b842-c44c89647716-000000@email.amazonses.com> References: <20180801200418.1325826-1-jeremy.linton@arm.com> <20180801200418.1325826-2-jeremy.linton@arm.com> User-Agent: Alpine 2.21 (DEB 202 2017-01-01) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII X-SES-Outgoing: 2018.08.02-54.240.9.99 Feedback-ID: 1.us-east-1.fQZZZ0Xtj2+TD7V5apTT/NrT6QKuPgzCT/IC7XYgDKI=:AmazonSES Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 1 Aug 2018, Jeremy Linton wrote: > diff --git a/mm/slub.c b/mm/slub.c > index 51258eff4178..e03719bac1e2 100644 > --- a/mm/slub.c > +++ b/mm/slub.c > @@ -2519,6 +2519,8 @@ static void *___slab_alloc(struct kmem_cache *s, gfp_t gfpflags, int node, > if (unlikely(!node_match(page, searchnode))) { > stat(s, ALLOC_NODE_MISMATCH); > deactivate_slab(s, page, c->freelist, c); > + if (!node_online(searchnode)) > + node = NUMA_NO_NODE; > goto new_slab; > } > } > Would it not be better to implement this check in the page allocator? There is also the issue of how to fallback to the nearest node. NUMA_NO_NODE should fallback to the current memory allocation policy but it seems by inserting it here you would end up just with the default node for the processor.