From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-qt1-f178.google.com (mail-qt1-f178.google.com [209.85.160.178]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E24692DCC1C for ; Wed, 3 Dec 2025 09:23:23 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.160.178 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764753806; cv=none; b=uB1sv/92Yt2dcx+W6qHCOSSmnlwAGvMFG6XLyQqybbn9/3MOeROXPqQsjrPAZZz34+HRwtlDMtSxfour9PFohoRARZultwzTjfd8+Qv72TIrghiiT5SEQE4luT/2UuFgyjDc+rF4M14Oml3SsnWyizrkcRKewGRqrdW8mZmwnbc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764753806; c=relaxed/simple; bh=GfZfkN1PIZvO/MpAoKI4h9bC6/kjcFTWvKgK4g45Sqc=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=I4Y4ZP3D5z+PNexwD+J+7wFopeHBxNNgtkjppVZu2hE5Szjs4W2x3ZSzPTr+DfCNZhxrcK2+DbmNpa6AM09HPVTqHS+LUy7Uw92uf1Bctd9dQyMpYgphMWMdDsD9UVV5qJ/dkTDw37V+QVFwdwBPGtH1GIv339WZhXU1PsAhZNY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=gourry.net; spf=pass smtp.mailfrom=gourry.net; dkim=pass (2048-bit key) header.d=gourry.net header.i=@gourry.net header.b=D/NKKTMW; arc=none smtp.client-ip=209.85.160.178 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=gourry.net Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gourry.net Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gourry.net header.i=@gourry.net header.b="D/NKKTMW" Received: by mail-qt1-f178.google.com with SMTP id d75a77b69052e-4eda26a04bfso71281031cf.2 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=vger.kernel.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=D/NKKTMWBcOQ6vJ2CHiOiwb7nxqC9HVOFBBc5h4yxyEBOTQKXvYCLgdbcfhPLf9dA7 qR1DbzmMco+w6kiPiiNN3h1+K6bTcWCb4T5xVT9j0HyWLbRCJwSuab4Hyv9YJ+hgG+Fl IBPx6MX+ZLrHmF+qaFEvtRbQwkJAiRhBzysB78uWwmq8kSpeqxXin/kY+/Suxokg+cCC 6FRHtuzAAcdKEekM8WzDrbayAmWiCxF7wrHDL3YF0/RQEr28WMEj5P492LRSKj1ldeSr fWEoOAOE1kw7YJzVefVQ+6CfgO0d8uXFN3KR0XMdoXmR0pBWRI2qN6Wd4ICSuu+dh/cj 3UqQ== 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=kvt3gW9lQFG2RDEy64u4lRF3T0Q19zvPTn2EuYtLN26877Tq3oHLaqoNmCFJXVNMJH kE9up/q7PS3xLHCpZZxf3TDa4mW6fL0daohU+y65M1PxGUQIxNjKXcVLzlQn0kk5IH36 FYiy72Me8AW2JVC7oBWOheTjFxRL7Rv/ZW4ldwL/v1KVkHBVw3c7s6abVzKsM3uRHYtt Uud3+zDW4Mya1losyCp/A1nTA20uA11Cte45gVEAbqxU850ZYkb6NOzl5hW4ytyij49b LsPPxDqewYfpQ7/6RkqsUiqQuJCbBxfbJwq/LiXTh3EQRiyQILYoKcfMiDfTfe4tvrDy K2pQ== X-Forwarded-Encrypted: i=1; AJvYcCUuaMNiRKIXf2j3mcxYYrUK1LZjT7XjZV5k3fNxLSHbFQXw2T/U2+lQ5rnUk3vBZ3MMkPeMi9nlbyTbvSc=@vger.kernel.org X-Gm-Message-State: AOJu0YwrfsSK8m2SlVwmLM6gMuGNtLGPjrhF4cw2/poSGdvVImZSxlQy yizd5G1T3Kzx/UrTxma0kjWlbg7kpDx0evqvhbJNqJ8dfICYhOhT1kvzHAoaS04+2U8= X-Gm-Gg: ASbGncvWcVssjUWLBoRfZ/ib+TvcVxnyA3CCWdaRS74A3E+dDWD6K/kr7S935vUMw+b 7v+YjAGuhvoE+M2K0J3/SuBy9/71pb4uAaVuqm2NyEqqXACszwCKero8WD/MOKrG1xTZcKOR5+K k4YL+L9FrNjASqR1TAF6XOn3mt0XoJe0UbY8yBG9lLeg7NjwupDFCxWy5Ueu3JkpugC9+0pwOuc cyv+8qYPRqH1FRRUelnmObqYzmUg0Q5GscTp4NfA+QQWRLCRxpKzJSxrlP7gFrFhpwfT+pipb+6 61Q09xEoI/H+eXFJEXmpkhCXDvU7WtcRtgGVuQihC7oJ8FkFq+ep8kK8bXxoB8zWMOfM1NLQmbB sERHXVhJCXj+LzRZuLX+rE9kOLHggKyvcrQuaFmKqni/9/IiOSjOqgNYRGSjhax18tXg8MsqMHz DAU1BWztrQcZHNZv+Cowxd8Gmbd9gYy0CU8BryjVOfbD19YDZDwc8nFBPI2nDa6xgvYFM1yw== 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> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <9de2f7e2-a202-499d-8858-6936beb251d9@kernel.org> 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