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 7636DC4338F for ; Wed, 28 Jul 2021 16:14:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5C57C604DB for ; Wed, 28 Jul 2021 16:14:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229763AbhG1QOr (ORCPT ); Wed, 28 Jul 2021 12:14:47 -0400 Received: from smtp-out1.suse.de ([195.135.220.28]:54030 "EHLO smtp-out1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229581AbhG1QOo (ORCPT ); Wed, 28 Jul 2021 12:14:44 -0400 Received: from relay2.suse.de (relay2.suse.de [149.44.160.134]) by smtp-out1.suse.de (Postfix) with ESMTP id ACF7922293; Wed, 28 Jul 2021 16:14:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1627488881; 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=IHsmSEwyJKjFPT6o6Jf3KVrrIV9uhwBf5+FjxQysrnU=; b=DWmlOTBxIuI1aOJ4GBOZis5+D04UJdWZgAlPGcbW5MArbb71lIMzE9gY5Nj8so8tF1xfQk YXMNe2gYORFFM4LQ/K7eSfUd5NrLlxYP+SdoI/vT0P6XFqRPOX/zGM3Jrrv+3oXGgMa/QO lWw4aGJbfxREUUUowIGjGFi7mJFIooI= 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 7F538A3B81; Wed, 28 Jul 2021 16:14:41 +0000 (UTC) Date: Wed, 28 Jul 2021 18:14:41 +0200 From: Michal Hocko To: Feng Tang Cc: linux-mm@kvack.org, Andrew Morton , David Rientjes , Dave Hansen , Ben Widawsky , linux-kernel@vger.kernel.org, linux-api@vger.kernel.org, Andrea Arcangeli , Mel Gorman , Mike Kravetz , Randy Dunlap , Vlastimil Babka , Andi Kleen , Dan Williams , ying.huang@intel.com 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> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210728151810.GD43486@shbuild999.sh.intel.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed 28-07-21 23:18:10, Feng Tang 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); > > page = __alloc_pages(((gfp | __GFP_NOWARN) & ~__GFP_DIRECT_RECLAIM), > order, pnid, &pol->nodes); > if (!page) > page = __alloc_pages(gfp, order, lnid, NULL); > return page; No. I really meant to get a node argument and use it as it is. Your callers already have some node preferences. Usually a local node and as we have a nodemask here then we do not really need to have any special logic here as mentioned in other email. The preferred node will act only as a source for the zone list. -- Michal Hocko SUSE Labs