From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 487523161A1; Fri, 26 Jun 2026 18:05:16 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782497117; cv=none; b=oDhlL5Y8N6x89bnovSYT7qS98WLRQz/DqVdpNyZ9ti+140YFBiT0HHx7VmJbvhQMDU66q7iy+KyWC73nOMW30/uZqXepaDtPZCr7Y7J7SnrQLJAI4NisBomzJcalrWK9sBQQHH9H6mn1gERN3vQsmjn9LAJj9Yaj9bxxis7Vszg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782497117; c=relaxed/simple; bh=JCJoFDG0qYd1PLil+ubkJCcSvKpGgC+mRent2Za8zhY=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=uGTbvYFbxp2F722u8pmRTkL9qC5qOWrVovObyC7Eo7eFbaxEX8YEdBGowPDbb3Cw+WhrwG93EXEh7daxSiwrj1iidQbCdqGIvTmSOcGLtvW4/ncMDyEPoiBPw7DCbY00vg89y3zPm+t+yziVqbdqftZkjWuza5bI1W+U8K8IzXg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=RWQRTWo/; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="RWQRTWo/" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 79F171F000E9; Fri, 26 Jun 2026 18:05:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1782497115; bh=fGiMyZB/kEhf07t+JFhkktFDb6T15Rf253lpTmaTVd8=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=RWQRTWo/O74n4A8v4P+Qyk3xgKStasPuZl6B7LVJ5wjaiALscfqq3SAfKa+w4+OQA FoXgyKGVvOeF8Z1Vi9qJ5l/MYpAHoPt0ZRQn00vUIcY3HrM82aA4S8UiuPcfaZfZNd t850CYdcz+VqiDQls9RsFY/JrIa5Xqt2g2YKaZwz4UL2o3bUhBZYGli3c6ubwjL6+0 SkoSXh+vnsLm+eUoMO9GJE3sE4cwTXdr8M7Yjs3X2cqSyVSp5t9lExOaDSXj3b42HU faUqhcmcq/+zhWKeqTFFQQDtztGavuSbocqtkCrnsmzjBgmWd0ww3MdqT5ikusnD4I /AI9JO7i8hEQA== Message-ID: <10824fdd-0abf-44ad-9a2f-e62aeb669195@kernel.org> Date: Fri, 26 Jun 2026 20:05:07 +0200 Precedence: bulk X-Mailing-List: linux-rt-devel@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2 02/13] mm/page_alloc: some renames to clarify alloc_flags scopes Content-Language: en-US To: Brendan Jackman , Suren Baghdasaryan , Brendan Jackman Cc: Andrew Morton , 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 , "Harry Yoo (Oracle)" , Gregory Price , Alexei Starovoitov , Matthew Wilcox , linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-rt-devel@lists.linux.dev References: <20260622-alloc-trylock-v2-0-31f31367d420@google.com> <20260622-alloc-trylock-v2-2-31f31367d420@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: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit On 6/24/26 18:13, Brendan Jackman wrote: > On Wed Jun 24, 2026 at 3:03 PM UTC, Suren Baghdasaryan wrote: >> On Mon, Jun 22, 2026 at 3:01 AM Brendan Jackman wrote: >>> >>> It's pretty confusing that: >>> >>> - The slowpath and fastpath have a totally distinct set of alloc_flags. >>> >>> - gfp_to_alloc_flags() sounds generic but it only influences the >>> slowpath. >>> >>> - prepare_alloc_pages() is generic in that it sets up the >>> alloc_context, but the alloc_flags it generates are only used for the >>> fastpath. >> >> I understand you want to clarify the usage but this particular point >> seems to be an implementation detail. IOW, if tomorrow >> __alloc_frozen_pages_noprof() is changed to use alloc_flags when >> calling __alloc_pages_slowpath(), would we be renaming it back? So, I >> would suggest keeping alloc_flags as is in prepare_alloc_pages() > > I would say yes, we should rename it even though it might mean having to > rename it back later. IMO it's very useful to make it clear to the > reader that they also need to look elsewhere to find the slowpath flag > logic, without them having to notice this rather odd detail of > __alloc_frozen_pages_noprof(). > > But, yeah I guess prepare_alloc_pages() doesn't really care that its > caller is only using the result for the fastpath so I could see the > rationale for keeping the arg as alloc_flags... > >> and its callers. > > ... but for it's caller I really do think the rename is necessary and > doesn't really have any downside? Especially once alloc_context gets an > alloc_flags field as it does later in the series. I don't mind either of the renames. It's all page_alloc.c internal anyway. >> The rest LGTM. > > Thanks as always, I appreciate the review.