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=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable 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 4B62FC432BE for ; Wed, 28 Jul 2021 16:15:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 26B5D6101C for ; Wed, 28 Jul 2021 16:15:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229826AbhG1QPk (ORCPT ); Wed, 28 Jul 2021 12:15:40 -0400 Received: from smtp-out2.suse.de ([195.135.220.29]:43294 "EHLO smtp-out2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229879AbhG1QP2 (ORCPT ); Wed, 28 Jul 2021 12:15:28 -0400 Received: from relay2.suse.de (relay2.suse.de [149.44.160.134]) by smtp-out2.suse.de (Postfix) with ESMTP id 5DAC31FFD4; Wed, 28 Jul 2021 16:15:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1627488925; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=xoPVca8js9y9snyRSKAlYaCIdY+QKI6XS6rLmdx3N8I=; b=uvq87d8IoaGI4sM7/K/O/NBMWzeDchWDqTXdTXVA/6AWqym+4TC0zR4+d5VQkLb/fEccNA eDkG7yq6BDC11nr0pOPxPrUIQ0RWoKszm3oZzf4YOJkNBKuaFNyvZN205v5IZAr+OkXYcs 9TbtHt7pGO+19aM2HKkp7uObQSXkAhY= Received: from suse.cz (unknown [10.100.201.86]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by relay2.suse.de (Postfix) with ESMTPS id 2E979A3B84; Wed, 28 Jul 2021 16:15:25 +0000 (UTC) Date: Wed, 28 Jul 2021 18:15:24 +0200 From: Michal Hocko To: Feng Tang Cc: "linux-mm@kvack.org" , Andrew Morton , David Rientjes , "Hansen, Dave" , "Widawsky, Ben" , "linux-kernel@vger.kernel.org" , "linux-api@vger.kernel.org" , Andrea Arcangeli , Mel Gorman , Mike Kravetz , Randy Dunlap , Vlastimil Babka , Andi Kleen , "Williams, Dan J" , "Huang, Ying" Subject: Re: [PATCH v6 2/6] mm/memplicy: add page allocation function for MPOL_PREFERRED_MANY policy Message-ID: References: <1626077374-81682-1-git-send-email-feng.tang@intel.com> <1626077374-81682-3-git-send-email-feng.tang@intel.com> <20210728151810.GD43486@shbuild999.sh.intel.com> <20210728152507.GE43486@shbuild999.sh.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210728152507.GE43486@shbuild999.sh.intel.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed 28-07-21 23:25:07, Feng Tang wrote: > On Wed, Jul 28, 2021 at 11:18:10PM +0800, Tang, Feng wrote: > > On Wed, Jul 28, 2021 at 02:42:26PM +0200, Michal Hocko wrote: > > > On Mon 12-07-21 16:09:30, Feng Tang wrote: > > > > The semantics of MPOL_PREFERRED_MANY is similar to MPOL_PREFERRED, > > > > that it will first try to allocate memory from the preferred node(s), > > > > and fallback to all nodes in system when first try fails. > > > > > > > > Add a dedicated function for it just like 'interleave' policy. > > > > > > > > Link: https://lore.kernel.org/r/20200630212517.308045-9-ben.widawsky@intel.com > > > > Suggested-by: Michal Hocko > > > > Co-developed-by: Ben Widawsky > > > > Signed-off-by: Ben Widawsky > > > > Signed-off-by: Feng Tang > > > > > > It would be better to squash this together with the actual user of the > > > function added by the next patch. > > > > Ok, will do > > > > > > --- > > > > mm/mempolicy.c | 19 +++++++++++++++++++ > > > > 1 file changed, 19 insertions(+) > > > > > > > > diff --git a/mm/mempolicy.c b/mm/mempolicy.c > > > > index 17b5800b7dcc..d17bf018efcc 100644 > > > > --- a/mm/mempolicy.c > > > > +++ b/mm/mempolicy.c > > > > @@ -2153,6 +2153,25 @@ static struct page *alloc_page_interleave(gfp_t gfp, unsigned order, > > > > return page; > > > > } > > > > > > > > +static struct page *alloc_page_preferred_many(gfp_t gfp, unsigned int order, > > > > + struct mempolicy *pol) > > > > > > We likely want a node parameter to know which one we want to start with > > > for locality. Callers should use policy_node for that. > > > > Yes, locality should be considered, something like this? > > > > int pnid, lnid = numa_node_id(); > > > > if (is_nodeset(lnid, &pol->nodes)) > > pnid = local_nid; > > else > > pnid = first_node(pol->nodes); > > One further thought is, if local node is not in the nodemask, > should we compare the distance of all the nodes in nodemask > to the local node and chose the shortest? Nope, That is zonelist for. Nodemask will do the rest. -- Michal Hocko SUSE Labs