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 DD58AFB44C5 for ; Fri, 24 Apr 2026 07:26:29 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id CDD716B0005; Fri, 24 Apr 2026 03:26:28 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id C8DF76B008A; Fri, 24 Apr 2026 03:26:28 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id B7BDD6B008C; Fri, 24 Apr 2026 03:26:28 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0012.hostedemail.com [216.40.44.12]) by kanga.kvack.org (Postfix) with ESMTP id A63646B0005 for ; Fri, 24 Apr 2026 03:26:28 -0400 (EDT) Received: from smtpin10.hostedemail.com (lb01b-stub [10.200.18.250]) by unirelay09.hostedemail.com (Postfix) with ESMTP id 346678C219 for ; Fri, 24 Apr 2026 07:26:28 +0000 (UTC) X-FDA: 84692616456.10.DB13C8D Received: from sea.source.kernel.org (sea.source.kernel.org [172.234.252.31]) by imf15.hostedemail.com (Postfix) with ESMTP id 54201A000B for ; Fri, 24 Apr 2026 07:26:26 +0000 (UTC) Authentication-Results: imf15.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b="C6/S2Vgh"; dmarc=pass (policy=quarantine) header.from=kernel.org; spf=pass (imf15.hostedemail.com: domain of david@kernel.org designates 172.234.252.31 as permitted sender) smtp.mailfrom=david@kernel.org ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1777015586; a=rsa-sha256; cv=none; b=zAVMU7MobcnHHUBbfcMJRbiVqI4FjKMGvkNEBT1wia43+dlDobkHHKucxK8Li6Huf1LbPc dc84u2U5Av85EvHlKXPNgjS6ZiepaoTVtYnIh5eJYLGHwz8zUuK+CKdTLIMMl1u32N4juy 4yvsJz92D3G+0g72T44PK5XFNl8PYZ4= ARC-Authentication-Results: i=1; imf15.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b="C6/S2Vgh"; dmarc=pass (policy=quarantine) header.from=kernel.org; spf=pass (imf15.hostedemail.com: domain of david@kernel.org designates 172.234.252.31 as permitted sender) smtp.mailfrom=david@kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1777015586; 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=Uje65QBS8nkEsvDxvrhqo0gIkSqNi9hZLH7oH59/OSg=; b=aCSFi0EmKxHgJECP8jZ758TLxMug6L8n/+JfZi2fyDvU7GMPsdlOHmuOpdrK1SGziIj2FQ v7AXzCxucNvgXxd4Nivx2q6401eogSrMyVBnuC2526d2ZHpJA0Sh4giVKu1tUQlpAW7LG3 5LpZyFY2ORvMB+VLQ8wzymFh+PM3RgE= Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sea.source.kernel.org (Postfix) with ESMTP id 08A5C444A0; Fri, 24 Apr 2026 07:26:25 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B53E4C19425; Fri, 24 Apr 2026 07:26:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1777015584; bh=5dmzXPh5bpR2t1b0uCMuOAqmdZYp5LGnT+Lwxr5M/oo=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=C6/S2VghcGegNnoRZvvUqEJC5Se8UaQriA/q3zpdTKceryHugwPWmW3hLepdvu1F+ 2pM+7AAqUoTcF2vFap5zsQEkhXzDgXYV78p0OUuJuBbqwBv3O/8qmPDmftAAl3npF0 xW/rsHX18FkQjJ+YAAeoc6OliYWOCGHcOEkrOczwwIR7JJOdORUKzS+ONFq0/aasrm hP3Sx+oWS6eTZF945+EHKpbaheEyeT0B2vNJIJS1KrWjWeYm3RWxWjG9f4dFefYjb2 Mwbeyt6hyV1NXzUvZvL3q+lySBi28hFUyuJMztEzXOwji88N0hU/rAZhQILqhxViia bamHzpaHrw1WA== Message-ID: Date: Fri, 24 Apr 2026 09:26:18 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2 1/5] mm: Introduce zone_appears_fragmented() To: =?UTF-8?Q?Thomas_Hellstr=C3=B6m?= , Matthew Brost Cc: intel-xe@lists.freedesktop.org, dri-devel@lists.freedesktop.org, Andrew Morton , Lorenzo Stoakes , "Liam R. Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Johannes Weiner References: <20260423055656.1696379-1-matthew.brost@intel.com> <20260423055656.1696379-2-matthew.brost@intel.com> <76191a17-18bf-4e9b-9ab5-dc9a48abfabb@kernel.org> <291406b26b8badf2e565996515931d9ebe50208f.camel@linux.intel.com> From: "David Hildenbrand (Arm)" Content-Language: en-US Autocrypt: addr=david@kernel.org; keydata= xsFNBFXLn5EBEAC+zYvAFJxCBY9Tr1xZgcESmxVNI/0ffzE/ZQOiHJl6mGkmA1R7/uUpiCjJ dBrn+lhhOYjjNefFQou6478faXE6o2AhmebqT4KiQoUQFV4R7y1KMEKoSyy8hQaK1umALTdL QZLQMzNE74ap+GDK0wnacPQFpcG1AE9RMq3aeErY5tujekBS32jfC/7AnH7I0v1v1TbbK3Gp XNeiN4QroO+5qaSr0ID2sz5jtBLRb15RMre27E1ImpaIv2Jw8NJgW0k/D1RyKCwaTsgRdwuK Kx/Y91XuSBdz0uOyU/S8kM1+ag0wvsGlpBVxRR/xw/E8M7TEwuCZQArqqTCmkG6HGcXFT0V9 PXFNNgV5jXMQRwU0O/ztJIQqsE5LsUomE//bLwzj9IVsaQpKDqW6TAPjcdBDPLHvriq7kGjt WhVhdl0qEYB8lkBEU7V2Yb+SYhmhpDrti9Fq1EsmhiHSkxJcGREoMK/63r9WLZYI3+4W2rAc UucZa4OT27U5ZISjNg3Ev0rxU5UH2/pT4wJCfxwocmqaRr6UYmrtZmND89X0KigoFD/XSeVv jwBRNjPAubK9/k5NoRrYqztM9W6sJqrH8+UWZ1Idd/DdmogJh0gNC0+N42Za9yBRURfIdKSb B3JfpUqcWwE7vUaYrHG1nw54pLUoPG6sAA7Mehl3nd4pZUALHwARAQABzS5EYXZpZCBIaWxk ZW5icmFuZCAoQ3VycmVudCkgPGRhdmlkQGtlcm5lbC5vcmc+wsGQBBMBCAA6AhsDBQkmWAik AgsJBBUKCQgCFgICHgUCF4AWIQQb2cqtc1xMOkYN/MpN3hD3AP+DWgUCaYJt/AIZAQAKCRBN 3hD3AP+DWriiD/9BLGEKG+N8L2AXhikJg6YmXom9ytRwPqDgpHpVg2xdhopoWdMRXjzOrIKD g4LSnFaKneQD0hZhoArEeamG5tyo32xoRsPwkbpIzL0OKSZ8G6mVbFGpjmyDLQCAxteXCLXz ZI0VbsuJKelYnKcXWOIndOrNRvE5eoOfTt2XfBnAapxMYY2IsV+qaUXlO63GgfIOg8RBaj7x 3NxkI3rV0SHhI4GU9K6jCvGghxeS1QX6L/XI9mfAYaIwGy5B68kF26piAVYv/QZDEVIpo3t7 /fjSpxKT8plJH6rhhR0epy8dWRHk3qT5tk2P85twasdloWtkMZ7FsCJRKWscm1BLpsDn6EQ4 jeMHECiY9kGKKi8dQpv3FRyo2QApZ49NNDbwcR0ZndK0XFo15iH708H5Qja/8TuXCwnPWAcJ DQoNIDFyaxe26Rx3ZwUkRALa3iPcVjE0//TrQ4KnFf+lMBSrS33xDDBfevW9+Dk6IISmDH1R HFq2jpkN+FX/PE8eVhV68B2DsAPZ5rUwyCKUXPTJ/irrCCmAAb5Jpv11S7hUSpqtM/6oVESC 3z/7CzrVtRODzLtNgV4r5EI+wAv/3PgJLlMwgJM90Fb3CB2IgbxhjvmB1WNdvXACVydx55V7 LPPKodSTF29rlnQAf9HLgCphuuSrrPn5VQDaYZl4N/7zc2wcWM7BTQRVy5+RARAA59fefSDR 9nMGCb9LbMX+TFAoIQo/wgP5XPyzLYakO+94GrgfZjfhdaxPXMsl2+o8jhp/hlIzG56taNdt VZtPp3ih1AgbR8rHgXw1xwOpuAd5lE1qNd54ndHuADO9a9A0vPimIes78Hi1/yy+ZEEvRkHk /kDa6F3AtTc1m4rbbOk2fiKzzsE9YXweFjQvl9p+AMw6qd/iC4lUk9g0+FQXNdRs+o4o6Qvy iOQJfGQ4UcBuOy1IrkJrd8qq5jet1fcM2j4QvsW8CLDWZS1L7kZ5gT5EycMKxUWb8LuRjxzZ 3QY1aQH2kkzn6acigU3HLtgFyV1gBNV44ehjgvJpRY2cC8VhanTx0dZ9mj1YKIky5N+C0f21 zvntBqcxV0+3p8MrxRRcgEtDZNav+xAoT3G0W4SahAaUTWXpsZoOecwtxi74CyneQNPTDjNg azHmvpdBVEfj7k3p4dmJp5i0U66Onmf6mMFpArvBRSMOKU9DlAzMi4IvhiNWjKVaIE2Se9BY FdKVAJaZq85P2y20ZBd08ILnKcj7XKZkLU5FkoA0udEBvQ0f9QLNyyy3DZMCQWcwRuj1m73D sq8DEFBdZ5eEkj1dCyx+t/ga6x2rHyc8Sl86oK1tvAkwBNsfKou3v+jP/l14a7DGBvrmlYjO 59o3t6inu6H7pt7OL6u6BQj7DoMAEQEAAcLBfAQYAQgAJgIbDBYhBBvZyq1zXEw6Rg38yk3e EPcA/4NaBQJonNqrBQkmWAihAAoJEE3eEPcA/4NaKtMQALAJ8PzprBEXbXcEXwDKQu+P/vts IfUb1UNMfMV76BicGa5NCZnJNQASDP/+bFg6O3gx5NbhHHPeaWz/VxlOmYHokHodOvtL0WCC 8A5PEP8tOk6029Z+J+xUcMrJClNVFpzVvOpb1lCbhjwAV465Hy+NUSbbUiRxdzNQtLtgZzOV Zw7jxUCs4UUZLQTCuBpFgb15bBxYZ/BL9MbzxPxvfUQIPbnzQMcqtpUs21CMK2PdfCh5c4gS sDci6D5/ZIBw94UQWmGpM/O1ilGXde2ZzzGYl64glmccD8e87OnEgKnH3FbnJnT4iJchtSvx yJNi1+t0+qDti4m88+/9IuPqCKb6Stl+s2dnLtJNrjXBGJtsQG/sRpqsJz5x1/2nPJSRMsx9 5YfqbdrJSOFXDzZ8/r82HgQEtUvlSXNaXCa95ez0UkOG7+bDm2b3s0XahBQeLVCH0mw3RAQg r7xDAYKIrAwfHHmMTnBQDPJwVqxJjVNr7yBic4yfzVWGCGNE4DnOW0vcIeoyhy9vnIa3w1uZ 3iyY2Nsd7JxfKu1PRhCGwXzRw5TlfEsoRI7V9A8isUCoqE2Dzh3FvYHVeX4Us+bRL/oqareJ CIFqgYMyvHj7Q06kTKmauOe4Nf0l0qEkIuIzfoLJ3qr5UyXc2hLtWyT9Ir+lYlX9efqh7mOY qIws/H2t In-Reply-To: <291406b26b8badf2e565996515931d9ebe50208f.camel@linux.intel.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Rspamd-Queue-Id: 54201A000B X-Rspamd-Server: rspam12 X-Stat-Signature: cn79nkxfw7gz4z3ujymd8zk99o3ebqay X-Rspam-User: X-HE-Tag: 1777015586-222199 X-HE-Meta: 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 bw9nRlQ2 1Oljia+gf3EFppA2g+EvLI+ttVsGHXs496TnTbE6MdBiYamvUJl15pdEhzd90UoEIhMJPUkJmPXLD673xbwll0y304sNRoHXJBLO9e/ddypxltzCn4SitIvhli4vYVlvcbZBjPAaDhOu1s5x8tfeP2YU9EDJT+6Dd85AfQu44TzcCtcoJwBE6Bb2nibuU9SmTau+8xnDFswzXlz8UW2WzxA7yP3Y7zdpCNL9X1PiAbjho0oCgRRrTGQrV+DHK3ghMhgpmCR67s0sv9VCz1TWi/caI0OIGs+X4V9rs6vKM0UMTdaz1i6Q15nSmjpycqAITVrTny98M/irB1fbIxoEw2na7CvALmlMp/K/dvhmMzG0ptIk/XWYZ39r6KjH5DfYXSV94tzEvd8ND0N8= Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 4/24/26 09:05, Thomas Hellström wrote: > On Thu, 2026-04-23 at 15:21 -0700, Matthew Brost wrote: >> On Thu, Apr 23, 2026 at 12:08:36PM -0700, Matthew Brost wrote: >>> >>> If the order were included in shrink_control, there is about a 95% >>> certain that this change would allow TTM / Xe to break the >>> problematic >>> kswapd feedback loop. This may also better express the intent of >>> the >>> problem we are trying to fix here. >>> >>> For reference, the cover letter [1] details the problem. >>> >>> Any guidance from the core MM folks would be appreciated—would >>> adding >>> the order to shrink_control be an acceptable solution? >>> >>> Matt >>> >>> [1] https://patchwork.freedesktop.org/series/165330/ >>> >> >> It doesn't look like __GFP_NORETRY, __GFP_RETRY_MAYFAIL, __GFP_NOFAIL >> make it to the sc->gfp_mask flags from the caller and get into kswapd >> loop... > > Perhaps that's because they mostly (only?) make sense from direct > reclaim? Looks like the trace is from kswapd. kswap obtains the desired order through pgdat->kswapd_order, as a hint from allocation code (wakeup_kswapd). The order can be easily merged (just use the max) We do have the gfp_flags there, but merging them from different wakeups is a bit more tricky (and when to reset?). Assume we have one urgent request for order-0 and one non-urgent (noretry,nofail, ...) request for order-9, we'd have to figure out a way how to represent that. Gets more complicated for more orders. Of course, we could have some kind of array, and try to store some "priority" per order. But I assume plumbing that into the rest of kswapd might not be that easy. -- Cheers, David