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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id AA757C43458 for ; Tue, 30 Jun 2026 16:42:19 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 1065D6B00E2; Tue, 30 Jun 2026 12:42:16 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 068756B00E4; Tue, 30 Jun 2026 12:42:16 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id E73436B00E7; Tue, 30 Jun 2026 12:42:15 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0015.hostedemail.com [216.40.44.15]) by kanga.kvack.org (Postfix) with ESMTP id AD4206B00E2 for ; Tue, 30 Jun 2026 12:42:15 -0400 (EDT) Received: from smtpin11.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay02.hostedemail.com (Postfix) with ESMTP id 0A9ED120576 for ; Tue, 30 Jun 2026 16:42:15 +0000 (UTC) X-FDA: 84937146630.11.89BE8E6 Received: from sea.source.kernel.org (sea.source.kernel.org [172.234.252.31]) by imf17.hostedemail.com (Postfix) with ESMTP id 298C340002 for ; Tue, 30 Jun 2026 16:42:12 +0000 (UTC) Authentication-Results: imf17.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b=Mpjj1UpA; dmarc=pass (policy=quarantine) header.from=kernel.org; spf=pass (imf17.hostedemail.com: domain of vbabka@kernel.org designates 172.234.252.31 as permitted sender) smtp.mailfrom=vbabka@kernel.org ARC-Seal: i=1; a=rsa-sha256; d=hostedemail.com; s=arc-20220608; cv=none; t=1782837733; b=DgW54M+wORzICPFhce5j0zgZ1MsdopSTconeSShU7W5gTuR785XynOevGyL1rD6jxEEWiB 4UX/1DFv28GHD9H8dhWe4cs27wPq3SJwSDvK3aMln8Lvw0N7IaLnOeafs0mEs3EkEhRcDx Cs8Rbnfnd758tXTSoFc82t2QPAwdMdg= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1782837733; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=FGaQANRuz7ppZV2PSxCdI1jyGhFNKQCFfZRkpjfHIx4=; b=CdYcp01a4v1tdgutW5P0OQWrTdE5tJygkUz5X9aRnf4ShYNx5zNXoE6LDjGrCo9lMYU/+e KiZcuT/5P9CozYEPK4o1VfNfafEBHCkyOvpv54gKutgUWgtFG7tlu7p/3DkLKTdZjIh2Za pl+xKVR2siukESfNTXmq+zcqgAcRw4A= ARC-Authentication-Results: i=1; imf17.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b=Mpjj1UpA; dmarc=pass (policy=quarantine) header.from=kernel.org; spf=pass (imf17.hostedemail.com: domain of vbabka@kernel.org designates 172.234.252.31 as permitted sender) smtp.mailfrom=vbabka@kernel.org Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by sea.source.kernel.org (Postfix) with ESMTP id D328D43C8B; Tue, 30 Jun 2026 16:42:11 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 90ECF1F000E9; Tue, 30 Jun 2026 16:42:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1782837731; bh=FGaQANRuz7ppZV2PSxCdI1jyGhFNKQCFfZRkpjfHIx4=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=Mpjj1UpA9JvWJDddJxrWhkw/KgM7NeF2WyUc6ixJCeX2ovt8ol68V2rJtBbTDtFT8 Z3cPZHdMgHR6zxn+yzaF5QBu/zgeJa8rHKgCHWal563uBDK9MIrN+LfWBCR+uPMIzn TP2mR3hru6thL0WQDc7fJRQeuMyyCvOHj4WhMkdLmYrA/GIo8ktjRrxZg/PNw/51q7 W1ChdE9N1cO+m+vXnjmwi6f7WU7ztLvqVWettq9woeTZNmbmwsgji+rmzjbpXB4EYS 9BVHOhiuEUkBE6N41SiXWiAXR0daUye9ldy5nfBo5xfIchE/ceRZdcnk467CQ8x/iD JsDO+oNp5EdeA== Message-ID: Date: Tue, 30 Jun 2026 18:42:04 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v3 06/16] mm/page_alloc: relax GFP WARN in nolock allocs Content-Language: en-US To: Brendan Jackman , Andrew Morton , Suren Baghdasaryan , Michal Hocko , Johannes Weiner , Zi Yan , Muchun Song , Oscar Salvador , David Hildenbrand , Lorenzo Stoakes , "Liam R. Howlett" , Mike Rapoport , Matthew Brost , Joshua Hahn , Rakie Kim , Byungchul Park , Ying Huang , Alistair Popple , Hao Li , Christoph Lameter , David Rientjes , Roman Gushchin , Sebastian Andrzej Siewior , Clark Williams , Steven Rostedt Cc: "Harry Yoo (Oracle)" , Gregory Price , Alexei Starovoitov , Matthew Wilcox , Hao Ge , linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-rt-devel@lists.linux.dev References: <20260629-alloc-trylock-v3-0-57bef0eadbc2@google.com> <20260629-alloc-trylock-v3-6-57bef0eadbc2@google.com> From: "Vlastimil Babka (SUSE)" Autocrypt: addr=vbabka@kernel.org; keydata= xsFNBFZdmxYBEADsw/SiUSjB0dM+vSh95UkgcHjzEVBlby/Fg+g42O7LAEkCYXi/vvq31JTB KxRWDHX0R2tgpFDXHnzZcQywawu8eSq0LxzxFNYMvtB7sV1pxYwej2qx9B75qW2plBs+7+YB 87tMFA+u+L4Z5xAzIimfLD5EKC56kJ1CsXlM8S/LHcmdD9Ctkn3trYDNnat0eoAcfPIP2OZ+ 9oe9IF/R28zmh0ifLXyJQQz5ofdj4bPf8ecEW0rhcqHfTD8k4yK0xxt3xW+6Exqp9n9bydiy tcSAw/TahjW6yrA+6JhSBv1v2tIm+itQc073zjSX8OFL51qQVzRFr7H2UQG33lw2QrvHRXqD Ot7ViKam7v0Ho9wEWiQOOZlHItOOXFphWb2yq3nzrKe45oWoSgkxKb97MVsQ+q2SYjJRBBH4 8qKhphADYxkIP6yut/eaj9ImvRUZZRi0DTc8xfnvHGTjKbJzC2xpFcY0DQbZzuwsIZ8OPJCc LM4S7mT25NE5kUTG/TKQCk922vRdGVMoLA7dIQrgXnRXtyT61sg8PG4wcfOnuWf8577aXP1x 6mzw3/jh3F+oSBHb/GcLC7mvWreJifUL2gEdssGfXhGWBo6zLS3qhgtwjay0Jl+kza1lo+Cv BB2T79D4WGdDuVa4eOrQ02TxqGN7G0Biz5ZLRSFzQSQwLn8fbwARAQABzSNWbGFzdGltaWwg QmFia2EgPHZiYWJrYUBrZXJuZWwub3JnPsLBsAQTAQoAWhYhBKlA1DSZLC6OmRA9UCJPp+fM gqZkBQJqFFy6GxSAAAAAAAQADm1hbnUyLDIuNSsxLjEyLDIsMgIbAwUJGtCBUAULCQgHAwUV CgkICwUWAgMBAAIeBQIXgAAKCRAiT6fnzIKmZJIUEADFx/tREzUImHrEwVHeSvDFmA7tJysI UVrlvrM09E7GIuzphzv7jYmo8n3ANpCczLEVr4G0syYQdTigaZgv3+FQDIIzhKih1IHhu1Ei XHlywNWKnQxxQEUNi5Mwx43wQz5XVw9F1A7gtKBKNtfogO511hAbrzagrYajyQacEJ/+sfhZ 9Da8ltHIXD8pcYaHUfQgEusCgmEd9+KrUwrTbckFKmYq5chuE6yJ4J0EmWknL096jIE6CnzF FRslQ3B1UKDjxVsm1ZHfir5NeWszLkTvGFsddFaWTgh8UycESG6VQzKXjjewXu2pG7YQYRpj QKm1W5X2TkwWkXRBZTmfmbhxIUMh3+zf5wQ463rSmDN/8v81tdqBtAW6rH/kzg1GvkaTHXn0 507yEHFzBksk2viAuIxxr7km8+/KARYLIdGtx30EG8cKzAUZOK6WqxtNCsXUJNrVE8CWrCaD icoNu7Fs1c5hmPHdSTnU48ce67449DdnO4neLSNhRiGlMHJgfJUmgrxu/hcYeOZ3haWmEQ2w uW1Mh01OHi8QZHCEyAbABrPs9GUgccc/4eYXX9hIgxfSkYzn8f+8NuIFPWl/0uTvjgqU29FQ SbzOLxHq9439Ox40G5mS5eZXRGxITYR+6TXvRGI6P/264jvflnr/pDGUttaikU+0W+1uxgKH cmYbEc7ATQRbGTU1AQgAn0H6UrFiWcovkh6EXVcl+SeqyO6JHOPm+e9Wu0Vw+VIUvXZVUVVQ La1PQDUi6j00ChlcR66g9/V0sPIcSutacPKfdKYOBvzd4rlhL8rfrdEsQw5ApZxrA8kYZVMh FmBRKAa6wos25moTlMKpCWzTH84+WO5+ziCTsTUZASAToz3RdunTD+vQcHj0GqNTPAHK63sf bAB2I0BslZkXkY1RLb/YhuA6E7JyEd2pilZOrIuBGl/5q2qSakgnAVFWFBR/DO27JuAksYnq +aH8vI0xGvwn75KqSk4UzAkDzWSmO4ZHuahKtQgZNsMYV+PGayRBX9b9zbldzopoLBdqHc4n jQARAQABwsF8BBgBCgAmAhsMFiEEqUDUNJksLo6ZED1QIk+n58yCpmQFAmfIHFQFCRYU6J8A CgkQIk+n58yCpmS2PA//bqN1LfcotmArgElsa+0EGZSQlYgK48pm8WAeTXTngudP9IJ4SuKY HR5RNjHcBeqN+Me0zxRqYzRb8nGanHEkDyf4Im8DQM8d6vbyU+FcPmG4skud4kgS1zMHnlVd SXfSIwKC/hKgdHG8aBV7545Lz9X6Iohea+94wneD0aw/hqF+QWewGZhWJriWAZtvEkzNjQOi 4U9F/trLten/x7bpphDSnDMKJtITbtzATT1Dq7o7VpIUK1nCTQALMuMjKCdi8OdU/+V+R3O4 0PXWvX8qrvqYapVbZ+9KqT74FsuB0Ya9uXwgBF2Q6cRuETZk5vqaqKxzqoQZCO8AOz/58j6O 2RHNy/mZEN+7tJ5Tsq42zVJ4jxsT8b9YplavCMsnBgDeRWhcbYhCyttoL7nYISyWg4kQYZ/P wIV3OuNv2f8iKYsxNsRuClOAF82+gvqOy1/1pprFjy8uo2pkoOrb63aOP3vO5VHnRKgra6dq NcaZ+c6J4H+nEJGi2SkHAUJz5oBzuThvPudLvPA/SK8sKoM01IRxSihev/S/5WLazXB1PGem OCbvzC1IjWJJraxiDJ5IygokapUa2RP7+WBR22skQ3SSl6G107QgWKSyTOGWEaRmV53vxQLV jXuCmzSSasTL60zq5yGrT4/DYQVSNEUiUbG4pYekxJujNeEDkUlky0Y= In-Reply-To: <20260629-alloc-trylock-v3-6-57bef0eadbc2@google.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Rspamd-Server: rspam11 X-Rspamd-Queue-Id: 298C340002 X-Rspam-User: X-Stat-Signature: cnj97nhdp5of6sr9b8f18cqmu4irfdwn X-HE-Tag: 1782837732-181792 X-HE-Meta: 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 9fg9N0Cc QPve7/nIR6i3uR5hhu9SrnnVZD1eEKst/+tHvOy/RgtjovpTgKQWVYXIQ+INu460bHhHkuhUugqaIcLD9ZYFRlfnbDpNl3YybrbFmtVfaRVf4981cIKOKjoXunzhNxkeBbKUEHtdQSiCD87wZvdclHnxe/i4xNQa44vcNuK1M2nR+nm6gBy22PLZJIE5MxDxJgQM0lFXlJtc4JemcofRaKYKF5rfoHD5VzmYKoZ71sdrPU4SSq2D7AIvwK/JlJm+9k3K4Hoxl+eAnu9NDbUYpObzXTR4OzzKQ8wekW4zMpaaCyCOutvx3AJHTGRyoAXJqVhD+uIHbchAMf/pYJUEsxTTKKlD62kh3j3I8w3U/d3hCcWviUiXpmYLAF/3ABe2yxBjlK072ypLtLWNtYghkn/c9Lvokzwt5HCzxofpaQQRhgrwcVAMF6xIuYyvqWe9Nwupzn3jLtiLRrYcPjt/rsm8tPfL4V33om561BHHZTHwdtMU= Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 6/29/26 15:11, Brendan Jackman wrote: > This WARN forbids setting other flags than __GFP_ACCOUNT but we > unconditionally set the ones in gfp_nolock so they are certainly fine > for the caller to set. > > There are other GFP flags that are almost certainly fine to set here; > Willy noted GFP_HIGHMEM, GFP_DMA, GFP_MOVABLE and GFP_HARDWALL. But, > nolock allocation is rather special, so be conservative to try and > ensure we have a chance to think carefully before nontrivial new > usecases arise. > > Suggested-by: Matthew Wilcox > Link: https://lore.kernel.org/linux-mm/ajS96fWbG4dzP3u3@casper.infradead.org/ > Reviewed-by: Suren Baghdasaryan > Signed-off-by: Brendan Jackman Reviewed-by: Vlastimil Babka (SUSE) > --- > mm/page_alloc.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > index 8d409d075e3e9..9cb3f1665b41b 100644 > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -5355,7 +5355,8 @@ struct page *__alloc_frozen_pages_noprof(gfp_t gfp, unsigned int order, > return NULL; > > if (alloc_flags & ALLOC_NOLOCK) { > - VM_WARN_ON_ONCE(gfp & ~__GFP_ACCOUNT); > + /* Certain other flags could be supported later if needed. */ > + VM_WARN_ON_ONCE(gfp & ~(__GFP_ACCOUNT | gfp_nolock)); > if (!alloc_trylock_allowed()) > return NULL; > gfp |= gfp_nolock; >