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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E2548C433F5 for ; Wed, 13 Oct 2021 14:21:34 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 786C2610F8 for ; Wed, 13 Oct 2021 14:21:34 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 786C2610F8 Authentication-Results: mail.kernel.org; dmarc=fail (p=quarantine dis=none) header.from=suse.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvack.org Received: by kanga.kvack.org (Postfix) id 95D306B006C; Wed, 13 Oct 2021 10:21:33 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 90E426B0071; Wed, 13 Oct 2021 10:21:33 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 7FC26900002; Wed, 13 Oct 2021 10:21:33 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0254.hostedemail.com [216.40.44.254]) by kanga.kvack.org (Postfix) with ESMTP id 715C46B006C for ; Wed, 13 Oct 2021 10:21:33 -0400 (EDT) Received: from smtpin29.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 2AF7D8249980 for ; Wed, 13 Oct 2021 14:21:33 +0000 (UTC) X-FDA: 78691627266.29.4DBC72F Received: from smtp-out2.suse.de (smtp-out2.suse.de [195.135.220.29]) by imf01.hostedemail.com (Postfix) with ESMTP id B7066507DDFE for ; Wed, 13 Oct 2021 14:21:32 +0000 (UTC) Received: from relay2.suse.de (relay2.suse.de [149.44.160.134]) by smtp-out2.suse.de (Postfix) with ESMTP id 8390F2021C; Wed, 13 Oct 2021 14:21:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1634134891; 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=nATVPnj3CqCtmse/WE9rmVOe9/Z6OwtB0Ei+IfS0hpw=; b=lqeO9wPubdc+t1bQPVPVpPI73MFqflnTN20LGp5COcUKCDYhPFuTQsTalD5M42x9PITctu Pt3eL0Ppx/bk4xVwRms/zX71wS+AHvD0EmkxkNL/hc8FLZrQfJyeH/LXnrydGi8BUhXim6 yQ1Jyd4q+99IRRTDnbtZFa3TzBldMS0= 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 0B75EA3B81; Wed, 13 Oct 2021 14:21:26 +0000 (UTC) Date: Wed, 13 Oct 2021 16:21:30 +0200 From: Michal Hocko To: "Aneesh Kumar K.V" Cc: Andi Kleen , linux-mm@kvack.org, akpm@linux-foundation.org, Ben Widawsky , Dave Hansen , Feng Tang , Andrea Arcangeli , Mel Gorman , Mike Kravetz , Randy Dunlap , Vlastimil Babka , Dan Williams , Huang Ying Subject: Re: [RFC PATCH] mm/mempolicy: add MPOL_PREFERRED_STRICT memory policy Message-ID: References: <20211013094539.962357-1-aneesh.kumar@linux.ibm.com> <83483424-e617-51c4-d55c-6106e66e2659@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: B7066507DDFE X-Stat-Signature: 8jng39fb6zqu468um5cpbhahh3yob8f3 Authentication-Results: imf01.hostedemail.com; dkim=pass header.d=suse.com header.s=susede1 header.b=lqeO9wPu; dmarc=pass (policy=quarantine) header.from=suse.com; spf=pass (imf01.hostedemail.com: domain of mhocko@suse.com designates 195.135.220.29 as permitted sender) smtp.mailfrom=mhocko@suse.com X-HE-Tag: 1634134892-486808 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Wed 13-10-21 18:53:55, Aneesh Kumar K.V wrote: > On 10/13/21 18:46, Andi Kleen wrote: > > > > > The difference with MPOL_BIND is the ability to specify a preferred node > > > which is the first node in the nodemask argument passed. > > > > That's always the one with the lowest number. Isn't that quite limiting > > in practice? > > > > It seems if you really want to do that you would need another argument. > > > Yes. But that would make it a new syscall. Should we do that? Yes, I do not see any reasonable to cram this into the existing syscall. I am not yet sure what the syscall should look like though. I can see two usecases, one of the is a very specific node allocation fallback order requirement and another one is preferrence for a cpu less node over other nodes. Both are slightly different. -- Michal Hocko SUSE Labs