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 6A1D0D1266D for ; Wed, 3 Dec 2025 09:23:28 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id C22696B0031; Wed, 3 Dec 2025 04:23:27 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id BFAC96B0032; Wed, 3 Dec 2025 04:23:27 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id B37326B008A; Wed, 3 Dec 2025 04:23:27 -0500 (EST) 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 A26816B0031 for ; Wed, 3 Dec 2025 04:23:27 -0500 (EST) Received: from smtpin21.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay05.hostedemail.com (Postfix) with ESMTP id 7E75558E29 for ; Wed, 3 Dec 2025 09:23:25 +0000 (UTC) X-FDA: 84177621570.21.E2B06C5 Received: from mail-qt1-f177.google.com (mail-qt1-f177.google.com [209.85.160.177]) by imf06.hostedemail.com (Postfix) with ESMTP id AEC3618000B for ; Wed, 3 Dec 2025 09:23:23 +0000 (UTC) Authentication-Results: imf06.hostedemail.com; dkim=pass header.d=gourry.net header.s=google header.b=k49+nHHp; spf=pass (imf06.hostedemail.com: domain of gourry@gourry.net designates 209.85.160.177 as permitted sender) smtp.mailfrom=gourry@gourry.net; dmarc=none ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1764753803; 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: in-reply-to:in-reply-to:references:references:dkim-signature; bh=EFjX7Gas1ZYIoPQgX1ANr0djeVn/uypCOzwVMV3za7w=; b=dMTEnBq6AlyGo/sh7x+PMC8SFb53zyjRAHYTTyKY55l6TY5QIT0J2gWbHzt4w50dVC38mK kjdb/1gxxdvkoYXDkM1Xf/4kM00KBh+8AwZ2PrdjJ/ehYbVHoh6AFPbp7QoSNegjnmUdfH 5ubJqf4DNhNcx5CNiTRhR/pgU+UNMiw= ARC-Authentication-Results: i=1; imf06.hostedemail.com; dkim=pass header.d=gourry.net header.s=google header.b=k49+nHHp; spf=pass (imf06.hostedemail.com: domain of gourry@gourry.net designates 209.85.160.177 as permitted sender) smtp.mailfrom=gourry@gourry.net; dmarc=none ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1764753803; a=rsa-sha256; cv=none; b=D9HJfGrv/wwGX95ga/D58WL9pPGBxEewJXM8xpbIyhtqmsok/qY9KOjCUC6Sva5JgZqxJz rr6x1/F6BZSD/LsaTialr/eqpW8VbfPXp66RcAIJ5wer/K4Vs3Ov1RGqtCUijUwuSOUPk6 X/vk4EgBb9cDzQ8jK3BEtO0fXg7jyaQ= Received: by mail-qt1-f177.google.com with SMTP id d75a77b69052e-4eda6a8cc12so62553971cf.0 for ; Wed, 03 Dec 2025 01:23:23 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gourry.net; s=google; t=1764753803; x=1765358603; darn=kvack.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=EFjX7Gas1ZYIoPQgX1ANr0djeVn/uypCOzwVMV3za7w=; b=k49+nHHptx5Lyehd1zb97BWKVLXFE/xWKIkvnfIYUF+Ajzpp5fYLpzrcpWV4bqBWaZ 0WLVQSoHcYXEr2fOTkLglXksMvvrwgd/5mI1PvN2q+t2drTxl6tDDUZ5olNawcsotE22 ps640HJPNHHP0cpHOX8ErYmvZCQtQrs9DCL+iJ6rgut2UC/lq/VzFsMBcIzDtzArpjpA pZ4uelLM63QGmDrYpxqO2H3MxgCTvDJHmJA3sBWTk6L1UQFzwuNFBEm2qTVlTcdGg6EZ lU4Z6l1VNJ8971Y6wxjoaE6Nuklo93VX21k/vQ4/fUF9gcWWCbDk+X3rJzavCi8kOpTq 8jHw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1764753803; x=1765358603; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-gg:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=EFjX7Gas1ZYIoPQgX1ANr0djeVn/uypCOzwVMV3za7w=; b=BTEizDzremx8sRgI42fn6MocyHOyT7e0gI2zxJcj1zzTumSIWxDIQ+IPKZhE24UDus OKadx2XJkyuYZ3MDmtmkYRWqX7mCc02ox1e/bnVIDmiId1uNAPe83dcRqQxtdqsrqvrg 3CvD2MCp1lRr2syie3MdlIlB1+NYH/eYoeuLsUcCDUpazvclmKumw+hhx828oCX3USnP JPaYtoJIGqTmnOm04+hGI2IaDfJUmk59jPMX9yY0AkH1ti0qHAuDruEGAlk8kj+yHzB0 /t5H6VXnh9ZomKV72d2hNvDV8bSjmdvWBJiUHksYM2h4XwyO0jm73IHHLt+FW4H3K4x9 grpA== X-Forwarded-Encrypted: i=1; AJvYcCX0CU2L2Kn3i1JwBx0OWoDcfJiD8/uX8IWtRfRsHKQ7wiWAczmP0uD43GVbFQ497EN96NHJyQP+kg==@kvack.org X-Gm-Message-State: AOJu0Yyz9hs7I9dtVCeGi2BdZF8B7Q4kOHIKsfdBA9FiN8gXlUyoG85i ai/WtAaYTA5lI8jjXP9ZbopQEMuSnXpKRZPcsiOrz+7aNAoxd3KY0JgBcdRjLg/pljY= X-Gm-Gg: ASbGnctDZNLVZ0uh4zZSmWBxP6IqiAv32p+EUzlrNAHnPF25oZGR5fpxKF1br+I11wY rspoopAMPo6AHULDzGBbEeWhn9UkX5r8SyHVgs+S5VmcgvtBZVg74eURzHUCBkcI0Y1mC9XGSbw ha5JGsNfsqGJl8c/Vro9x54rKP3ZAq5+50PWewwhFe88lniAE6hmTJuDxFqt99YWV8Wyt4dLRhC jwRHqjz6BRKgArWV87WKP909biSzhjYd5vXznfdaaFmOEUzyV5ZmsWIT48gjGsmHMAsHlrEmW10 HlC2a11aLLrxZhQplUIRbR0X2PR7DUGCe0G+HzN0iqrKkeAe3ZLMrRT6MfebehkJZIx4IItiXGt Z/HOwjDVMrFTvmkvCwfaaFc/mgKX/BtklAmOOzatiSie4oNA8GHvXOEyu3Tivq043Wz6doMx2kS xFVbMJCkygVHRw+IXDx7aF5eTzYfg3MTHX3smZlSjgZ9MRT5a3ZtzDtUV6zIFZ3hodCndKeA== X-Google-Smtp-Source: AGHT+IHqPQaHW1DZ4s4jpY2crTNj/JQPWH3xZfsJp1SX8T9ifTYZwnPrkGsw5JGaEAmGRsm1E+BRkQ== X-Received: by 2002:ac8:5dc7:0:b0:4eb:a192:de99 with SMTP id d75a77b69052e-4f017695341mr21786921cf.76.1764753802764; Wed, 03 Dec 2025 01:23:22 -0800 (PST) Received: from gourry-fedora-PF4VCD3F (pool-96-255-20-138.washdc.ftas.verizon.net. [96.255.20.138]) by smtp.gmail.com with ESMTPSA id 6a1803df08f44-88652b492b3sm123488176d6.33.2025.12.03.01.23.20 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 03 Dec 2025 01:23:21 -0800 (PST) Date: Wed, 3 Dec 2025 04:23:20 -0500 From: Gregory Price To: "David Hildenbrand (Red Hat)" Cc: Michal Hocko , Andrew Morton , Aboorva Devarajan , vbabka@suse.cz, surenb@google.com, jackmanb@google.com, hannes@cmpxchg.org, ziy@nvidia.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Oscar Salvador , Juan Yescas Subject: Re: [PATCH] mm/page_alloc: make percpu_pagelist_high_fraction reads lock-free Message-ID: References: <20251201060009.1420792-1-aboorvad@linux.ibm.com> <20251201094112.07eb1e588b6da2ee70c4641d@linux-foundation.org> <47a8b4d5-f4d2-4772-b1b2-ee96bc21e742@kernel.org> <9de2f7e2-a202-499d-8858-6936beb251d9@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <9de2f7e2-a202-499d-8858-6936beb251d9@kernel.org> X-Rspamd-Queue-Id: AEC3618000B X-Rspamd-Server: rspam02 X-Stat-Signature: gbj39fz97uqt4niiahgr9oc9xupmhkjs X-Rspam-User: X-HE-Tag: 1764753803-730230 X-HE-Meta: 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 oe6wlTlA Z/G8fbEzXa0yEKXKLrb5q0o0hlyAWS+g2efrwfQ43AYLirzGiwchFbK6Mu8wMeFD/G58AzPQoT3UcYR4= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Wed, Dec 03, 2025 at 10:08:55AM +0100, David Hildenbrand (Red Hat) wrote: > On 12/3/25 10:02, Gregory Price wrote: > > > > My transient failure (although i'm not sure it was actually transient, i > > killed it and retried after a few minutes and it succeeded immediately) > > was on a ZONE_MOVABLE block. > > Okay, so that one should not bail out. Longterm pinnins must never end up on > such memory, and if it happens, we have to identify why and fix it. > > We have this known problem of "stream of short-term pinnings" that can > temporarily turn memory effectively unmovable. Juan will talk about that at > LPC [1]. Nice, fun, good topic. Looking forward to Japan n_n > > We have another set of problematic cases (vmsplice(), fuse) but I would > assume that these are not the cases you are hitting. > We do use fuse, but this system was relatively quiet when i tried this. We do have some proactive reclaim / demotion going on, but i don't think it was that (see below). > > > > Kind of suggested to me there was some bad condition the resolved once I > > took a second to release the lock and try again. > > Hard to tell I'm afraid. Do you still have the dump_folio() calls we print > when migration fails? > What luck, I do! :D And i just noticed it's the same page over and over [ 3404.119270] migrating pfn c06f176 failed ret:1 [ 3404.129152] page: refcount:4 mapcount:0 mapping:0000000061ca20ba index:0xad28e5b pfn:0xc06f176 [ 3404.148284] memcg:ffff88842e855000 [ 3404.155834] aops:btree_aops ino:1 [ 3404.163193] flags: 0x17ffff066c00420c(referenced|uptodate|workingset|private|node=1|zone=3|lastcpupid=0x1ffff) [ 3404.185408] raw: 17ffff066c00420c ffffc90066a13ca0 ffffc90066a13ca0 ffff88812b8502f8 [ 3404.202603] raw: 000000000ad28e5b ffff888859fd42d0 00000004ffffffff ffff88842e855000 [ 3404.219779] page dumped because: migration failure [ 3404.230610] migrating pfn c06f176 failed ret:1 [ 3404.240483] page: refcount:4 mapcount:0 mapping:0000000061ca20ba index:0xad28e5b pfn:0xc06f176 [ 3404.259603] memcg:ffff88842e855000 [ 3404.267152] aops:btree_aops ino:1 [ 3404.274511] flags: 0x17ffff066c00420c(referenced|uptodate|workingset|private|node=1|zone=3|lastcpupid=0x1ffff) [ 3404.296716] raw: 17ffff066c00420c ffffc90066a13ca0 ffffc90066a13ca0 ffff88812b8502f8 [ 3404.313909] raw: 000000000ad28e5b ffff888859fd42d0 00000004ffffffff ffff88842e855000 [ 3404.331102] page dumped because: migration failure [ 3404.341778] migrating pfn c06f176 failed ret:1 [ 3404.351658] page: refcount:4 mapcount:0 mapping:0000000061ca20ba index:0xad28e5b pfn:0xc06f176 [ 3404.370781] memcg:ffff88842e855000 [ 3404.378331] aops:btree_aops ino:1 [ 3404.385687] flags: 0x17ffff066c00420c(referenced|uptodate|workingset|private|node=1|zone=3|lastcpupid=0x1ffff) [ 3404.407895] raw: 17ffff066c00420c ffffc90066a13ca0 ffffc90066a13ca0 ffff88812b8502f8 [ 3404.425073] raw: 000000000ad28e5b ffff888859fd42d0 00000004ffffffff ffff88842e855000 [ 3404.442264] page dumped because: migration failure [ 3404.452928] migrating pfn c06f176 failed ret:1 [ 3404.462809] page: refcount:4 mapcount:0 mapping:0000000061ca20ba index:0xad28e5b pfn:0xc06f176 [ 3404.481948] memcg:ffff88842e855000 [ 3404.489511] aops:btree_aops ino:1 [ 3404.496899] flags: 0x17ffff066c00420c(referenced|uptodate|workingset|private|node=1|zone=3|lastcpupid=0x1ffff) [ 3404.519128] raw: 17ffff066c00420c ffffc90066a13ca0 ffffc90066a13ca0 ffff88812b8502f8 [ 3404.536332] raw: 000000000ad28e5b ffff888859fd42d0 00000004ffffffff ffff88842e855000 [ 3404.553534] page dumped because: migration failure [ 3404.564200] migrating pfn c06f176 failed ret:1 [ 3404.574077] page: refcount:4 mapcount:0 mapping:0000000061ca20ba index:0xad28e5b pfn:0xc06f176 [ 3404.593208] memcg:ffff88842e855000 [ 3404.600769] aops:btree_aops ino:1 [ 3404.608138] flags: 0x17ffff066c00420c(referenced|uptodate|workingset|private|node=1|zone=3|lastcpupid=0x1ffff) [ 3404.630355] raw: 17ffff066c00420c ffffc90066a13ca0 ffffc90066a13ca0 ffff88812b8502f8 [ 3404.647558] raw: 000000000ad28e5b ffff888859fd42d0 00000004ffffffff ffff88842e855000 [ 3404.664761] page dumped because: migration failure