From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793267980; b=DY+QIdnJyoJB02dgT4xNCZ4pKodxUoTPIHN6c7cxkUK0YFzn5iTk9qR/TQm7+/f9aSLl qGulkKSZlmLQgTlHjKmcLL+ZBXis+QGepUksN5sNKN0g/sBdzEyeAd9l/5+O/7A+ou1Oo A+hOwOHB7dYWJoOPsO0n85JsO+4reFX+iZBJ5Tco2WViCwktzMv5lKUIqP/Qn28jW7uHK QuT7m4lfGuziQMM53IX58VdcG0xZpaTM4V3JA4Q5Szlbn+TRJLyNkQNqCbOJyn8IqINyM vmUr5YSEAkG4bT17NbxZ5gFwc8BWCtBQL6vsNF4dVgjaw4p3Rngsedy/YaiXSmnFlCg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793267980; h=Received:DKIM-Signature:Message-ID:Date:MIME-Version:User-Agent: Subject:Content-Language:To:Cc:References:From:Autocrypt:In-Reply-To: Content-Type:Content-Transfer-Encoding; bh=U99SJ7R4mLLxhW7B2LnKG47mwU6pah+xCFdx+p50og8=; b=QODNXddUwnZFtr5LY+UfNMsW/abzckRdfKMwUkJYcFtZKOkhozQsmk9IhcshOS69Ju8r kkf8hZvpVf8/9Sr9dCgCFNmyY3aO+0JB/afm5Awke8h01ajznKdiBWUsIuOdPzD3+GAR1 bkeHTZNSmiMEQy+T+tBYU8N01g8Wlbd0j0bw5tJFvPBz5Jwsyb6WEvZsL7e/uHK1Q/hpx Wl3V9kmWt0uQk8S4Yk8dMwH6i51maW6sO/aVe2pNKLfiofYjdxnfQBt7gLDLnxpQRDOic wUEsHnsmLV9q1tZAChNlt/IxNfRkv2AGVTHZ2HaIYZu1yhDvOlXR5Gjg2mc2yrWnDSw== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=Zix5f4Ae; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6069F606A329; Thu, 29 Oct 2026 09:59:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=Zix5f4Ae Received: by smtp.kernel.org (Postfix) with ESMTPSA id 55C9E1F01825; Thu, 29 Oct 2026 09:59:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793267980; bh=U99SJ7R4mLLxhW7B2LnKG47mwU6pah+xCFdx+p50og8=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=Zix5f4AeG0b26CGKytIaRSw6ZEc3BYP6FNOflQjshf6oQ3fBYtCcKvD418n2O4idD VkC/KPqEkvzykEwu922IObYnxERDc7XkUgobdi8UU/njPjCnkOeMYsps1ZutSRPHjC NglNsTidAbDJJpEd+mFmX4esNqh/qJDQs5Iscg94kEYA9TK7o3+hcpNKOXI3l2uXHE uosyFJHk1JYglJomqxSnJlTghv5bHaGCcCFZlaG0/KesU7nluOqQeCvyb7UueHTHgb o78V8/RjkWyjJux2U3iC9Dlb0a8P9ffNnfw3DyjkFsxHxmgQ/jPHwLIp72Av380LX6 yNYLu/4sTdw/A== Message-ID: <1fc0caa5-43b1-487f-94cf-0d1aff4c03fd@kernel.org> Date: Thu, 29 Oct 2026 10:59:33 +0100 X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 1/2] mm: page_alloc: do not give all non-blocking requests reserve access Content-Language: en-US To: Andrew Morton , Christoph Hellwig Cc: Salvatore Dipietro , hannes@cmpxchg.org, abuehaze@amazon.com, alisaidi@amazon.com, blakgeof@amazon.com, brauner@kernel.org, brendan.jackman@linux.dev, david@redhat.com, dgc@kernel.org, dipietro.salvatore@gmail.com, djwong@kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-xfs@vger.kernel.org, matt@readmodwrite.com, mhocko@suse.com, ritesh.list@gmail.com, rvvandan@amazon.com, stable@vger.kernel.org, surenb@google.com, willy@infradead.org, ziy@nvidia.com References: <20261027150002.318916-1-dipiets@amazon.it> <20261028144148.GA14023@lst.de> <20261028225517.75e13881be22461a8c94e07d@linux-foundation.org> 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: <20261028225517.75e13881be22461a8c94e07d@linux-foundation.org> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 10/29/26 06:55, Andrew Morton wrote: > On Wed, 28 Oct 2026 15:41:48 +0100 Christoph Hellwig wrote: > >> On Tue, Oct 27, 2026 at 03:00:02PM +0000, Salvatore Dipietro wrote: >> > >> > Hi Johannes, >> > >> > Vlastimil asked that v6 of my page_alloc patch [1] not go to mainline >> > before these two patches land, so Andrew parked v6 at the tail of >> > mm-unstable and dropped its Cc: stable until then. >> > >> > Are you still planning to work on 1/2 and 2/2, and if so, do you have >> > a rough ETA? Or would you rather post them as a separate series as >> > they are? If anything is needed on my side to move them forward, I'm >> > happy to help. >> > >> > For what it's worth, I ran both stacked under v6 on v7.3-rc1 and saw >> > no performance difference on my benchmark with or without them. >> >> It would be really important to get some fix for this into 7.3. >> We can still perfect it later. > > What is "this"? You're referring to the performance regression which > Salvatore's "mm/page_alloc: avoid direct reclaim and compaction for > costly __GFP_NORETRY allocations" addresses? > > In > https://lore.kernel.org/all/9f415dc7-adad-4161-b20d-7c3173f50ff3@kernel.org/ > vbabka indicated that Fixes: 281dd25c1a01 is needed on that patch. The "that patch" being Johannes's and the v2 you picked up has it > patch I'm sitting on (below) has Fixes: 5d8edfb900d5. Please clarify. It's correct. > In > https://lore.kernel.org/all/c6e2c1e1-a285-406e-a2b6-c09e05df91d8@kernel.org/ > vbabka argued that Salvatore's "mm/page_alloc: avoid direct reclaim and > compaction for costly __GFP_NORETRY allocations" should be a 7.4 thing. > > So it's all clear as mud. Can people please clarify? > > I have hannes's series "mm: page_alloc: fix reserve access for > non-blocking requests, v2" in mm-hotfixes, planned for 7.4-rcX. > > Should I move Salvatore's "mm/page_alloc: avoid direct reclaim and > compaction for costly __GFP_NORETRY allocations, v6" into mm-hotfixes > also, and restore its cc:stable? > > My vote: "yes" - that's a pretty obnoxious perf regression. Yes please.