From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pg1-f200.google.com (mail-pg1-f200.google.com [209.85.215.200]) by kanga.kvack.org (Postfix) with ESMTP id 3D2966B0003 for ; Thu, 25 Oct 2018 00:59:30 -0400 (EDT) Received: by mail-pg1-f200.google.com with SMTP id r16-v6so4518887pgv.17 for ; Wed, 24 Oct 2018 21:59:30 -0700 (PDT) Received: from mx1.suse.de (mx2.suse.de. [195.135.220.15]) by mx.google.com with ESMTPS id cd15-v6si6899812plb.219.2018.10.24.21.59.28 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 24 Oct 2018 21:59:28 -0700 (PDT) Subject: Re: [PATCH 2/2] mm, thp: consolidate THP gfp handling into alloc_hugepage_direct_gfpmask References: <20180925120326.24392-1-mhocko@kernel.org> <20180925120326.24392-3-mhocko@kernel.org> <20180926133039.y7o5x4nafovxzh2s@kshutemo-mobl1> <20180926141708.GX6278@dhcp22.suse.cz> <20180926142227.GZ6278@dhcp22.suse.cz> <20181018191147.33e8d5e1ebd785c06aab7b30@linux-foundation.org> <20181019080657.GJ18839@dhcp22.suse.cz> <583b20e5-4925-e175-1533-5c2d2bab9192@suse.cz> <20181024161754.0d174e7c22113f4f8aad1940@linux-foundation.org> From: Vlastimil Babka Message-ID: <983e0c59-99ef-796c-bfc4-00e67782d1f1@suse.cz> Date: Thu, 25 Oct 2018 06:56:37 +0200 MIME-Version: 1.0 In-Reply-To: <20181024161754.0d174e7c22113f4f8aad1940@linux-foundation.org> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Andrew Morton Cc: Michal Hocko , "Kirill A. Shutemov" , Mel Gorman , David Rientjes , Andrea Argangeli , Zi Yan , Stefan Priebe - Profihost AG , linux-mm@kvack.org, LKML On 10/25/18 1:17 AM, Andrew Morton wrote: > On Mon, 22 Oct 2018 15:27:54 +0200 Vlastimil Babka wrote: > >>> : Moreover the oriinal code allowed to trigger >>> : WARN_ON_ONCE(policy->mode == MPOL_BIND && (gfp & __GFP_THISNODE)); >>> : in policy_node if the requested node (e.g. cpu local one) was outside of >>> : the mbind nodemask. This is not possible now. We haven't heard about any >>> : such warning yet so it is unlikely that it happens but still a signal of >>> : a wrong code layering. >> >> Ah, as I said in the other mail, I think it's inaccurate, the warning >> was not possible to hit. >> >> There's also a slight difference wrt MPOL_BIND. The previous code would >> avoid using __GFP_THISNODE if the local node was outside of >> policy_nodemask(). After your patch __GFP_THISNODE is avoided for all >> MPOL_BIND policies. So there's a difference that if local node is >> actually allowed by the bind policy's nodemask, previously >> __GFP_THISNODE would be added, but now it won't be. I don't think it >> matters that much though, but maybe the changelog could say that >> (instead of the inaccurate note about warning). Note the other policy >> where nodemask is relevant is MPOL_INTERLEAVE, and that's unchanged by >> this patch. > > So the above could go into the changelog, yes? Yeah. >> When that's addressed, you can add > > What is it that you'd like to see addressed? Purely changelog updates? Right. >> Acked-by: Vlastimil Babka > > Thanks. >