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]) by smtp.lore.kernel.org (Postfix) with ESMTP id CFB37C77B7C for ; Wed, 2 Jul 2025 17:39:06 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 55FD56B00C5; Wed, 2 Jul 2025 13:39:06 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 536D36B00C6; Wed, 2 Jul 2025 13:39:06 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 4263B6B00C7; Wed, 2 Jul 2025 13:39:06 -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 32AAF6B00C5 for ; Wed, 2 Jul 2025 13:39:06 -0400 (EDT) Received: from smtpin26.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay03.hostedemail.com (Postfix) with ESMTP id 04109B8A68 for ; Wed, 2 Jul 2025 17:39:05 +0000 (UTC) X-FDA: 83620035492.26.415BC10 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by imf19.hostedemail.com (Postfix) with ESMTP id 9A23A1A000A for ; Wed, 2 Jul 2025 17:39:03 +0000 (UTC) Authentication-Results: imf19.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=LCb65INa; spf=pass (imf19.hostedemail.com: domain of luizcap@redhat.com designates 170.10.129.124 as permitted sender) smtp.mailfrom=luizcap@redhat.com; dmarc=pass (policy=quarantine) header.from=redhat.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1751477943; 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=t5kc7QGkeiDNyd1vpvu2YlBzltMT97zD9Hu2apFeViM=; b=pEOrN6YEtlQerTio2cqM2GzRCj+lP5jFAdSzn2+pbDITomkbbaMfYpbelqud9cpb76/U7G pBe2O45TjtHWMQRUr0Cx/RLEJ4qbq8oxoHTtHZv1xB36+l2oLY1gffgNkAyDS3khsPTVc6 KVUuwcErpwHQiBgVPFzxqzgKAEI97r4= ARC-Authentication-Results: i=1; imf19.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=LCb65INa; spf=pass (imf19.hostedemail.com: domain of luizcap@redhat.com designates 170.10.129.124 as permitted sender) smtp.mailfrom=luizcap@redhat.com; dmarc=pass (policy=quarantine) header.from=redhat.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1751477943; a=rsa-sha256; cv=none; b=SSxt4Yrh+XERuEZx7mr6zGEeocfE1HiGDiILbCJTNUDt3eQDh1toaLW7+Y++NnXvdUvjgs UIpdWcIXYxjmC1nOYG1GREzD3eIEpLMeA0IclVXO9GvgObVgYW9l63hir5vaT/Xf8mRx05 xHO8GlhhA+L6wZgRDazM47cNZZQnHts= DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1751477942; h=from:from: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; bh=t5kc7QGkeiDNyd1vpvu2YlBzltMT97zD9Hu2apFeViM=; b=LCb65INadY7wU1g/XzZHAyJ6dYatu5RMgeoCQMY5uup5aXWeUDKzyN2BOyHhQ9uqVgWjjf RqqwFoiaULuuEXD94DQaZISvLwtAKIwznK4dQakXspJy1F75dVicn2IqmzBR2bUidJP2CS dWxSF/1/b+Hf1vMvKHpAvrxF5iygmNg= Received: from mail-oi1-f197.google.com (mail-oi1-f197.google.com [209.85.167.197]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-167-8uSBNTWTPNii8vlfjQe5Nw-1; Wed, 02 Jul 2025 13:38:59 -0400 X-MC-Unique: 8uSBNTWTPNii8vlfjQe5Nw-1 X-Mimecast-MFC-AGG-ID: 8uSBNTWTPNii8vlfjQe5Nw_1751477938 Received: by mail-oi1-f197.google.com with SMTP id 5614622812f47-40b6a97ccb9so2507607b6e.0 for ; Wed, 02 Jul 2025 10:38:59 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1751477938; x=1752082738; h=content-transfer-encoding:in-reply-to:from:content-language :references:cc:to:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=t5kc7QGkeiDNyd1vpvu2YlBzltMT97zD9Hu2apFeViM=; b=sEqNTpLHGXEAnNcj2ypyOMBWzyD57ps8P+GkdaFLcLAAlOCpoLHzxHUBpgd6SyDUkC dvUdq8L/tyUoBmmVjrj62fNpmmuMaq9JH4GCCJQN1x/tTXyegeq6nsASGMl7FK/c227a 9P91chYRPy4UOQ6de8r4Qkq0sTpYmFBsTx7jRX5J0kPtH0/e/QDffjW25OtX5n9zCo7L A69FLYWQuEJPSBJCdZrM5PRh9PbbSl0LPO4fNFz/iFZKwyBgHgjAHS6GyK2a5NH8YhsV 3MiX1fE9Je7N1QYkJ/xWajgD08tl89E2Cp2Obb3QGSlFD4zSiJapII/INeAQ1OUrJM8A BL+w== X-Forwarded-Encrypted: i=1; AJvYcCXoM+KCP/4g0GjwivpaoteCqRVNFhQ02iI5uUBEV/1ZWJKDC6NaCHI83sc2h9qfMfKz88CYzZpSbw==@kvack.org X-Gm-Message-State: AOJu0Yzc2EOEUaDpYoDRpj4m9vCFetJaiXviMx1g28TSqMsN6KV0evZy kWcMU63RnkilHSPQ9JB+5wHIB8HZ1tJ8OYBK4aAGmBQop3Cp7vPUxDIf/jaJgYiAPenWt7rsF+D CLVaqnAFvMN9UGz+nFs6bTKhOv/DDprSyHYHGdbizkvSsk9PdU33r X-Gm-Gg: ASbGncul0X/iS4mxSTYUSYGOR30PkhULKpLG27GvUkKHmtzFwc2kX8IEBVEe9r9AewB uI8FUj5yA3J2+ziAIVO5WUoS3h6M3zV8OIeI4LAuz84NAgn0F31q0o+E3ZRi9juCH/iIrI2KFTZ fXh2oGIDWtMmEgxMnDOSdC//TS5jUriXf6jFw7vmuM1ee6lDpXo4XmalOJ+8rLtes3unnrYFN9e 4r+UVgctYMc1GP1ArOgBRF5I13jjKV/jFPcp/QwuB7cEFPNSx1xgYcW202kb2Aui82/QKA1mCgx pr/DjNwQrBOP+gphsHh5l/q7 X-Received: by 2002:a05:6808:1a17:b0:40b:4436:46b6 with SMTP id 5614622812f47-40b8911280cmr2880869b6e.37.1751477938424; Wed, 02 Jul 2025 10:38:58 -0700 (PDT) X-Google-Smtp-Source: AGHT+IHdmoKE0spR7/KmpsUBXOZZSNIqASQZlCpgekGVNMtn3ZdZbAeHx4Uw+Ze21QoFB0abDOfubQ== X-Received: by 2002:a05:6808:1a17:b0:40b:4436:46b6 with SMTP id 5614622812f47-40b8911280cmr2880834b6e.37.1751477937870; Wed, 02 Jul 2025 10:38:57 -0700 (PDT) Received: from [192.168.2.110] ([69.156.206.24]) by smtp.gmail.com with ESMTPSA id 5614622812f47-40b3241f829sm2629594b6e.35.2025.07.02.10.38.56 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 02 Jul 2025 10:38:57 -0700 (PDT) Message-ID: <3c0eb35d-86e2-45ea-b933-32989c28963a@redhat.com> Date: Wed, 2 Jul 2025 13:38:45 -0400 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 2/3] proc: kpagecount: use snapshot_page() To: Shivank Garg , david@redhat.com, willy@infradead.org Cc: akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, lcapitulino@gmail.com References: <5e94d287b6174098938ddd9959cf3c0619fb610a.1750961812.git.luizcap@redhat.com> <3ee3adfc-5efc-43dd-9c75-23564fade7b3@amd.com> From: Luiz Capitulino In-Reply-To: <3ee3adfc-5efc-43dd-9c75-23564fade7b3@amd.com> X-Mimecast-Spam-Score: 0 X-Mimecast-MFC-PROC-ID: ImLQgJL430UGpwir1GZBBwGnG7wGaQxdmOFJaNvCn4E_1751477938 X-Mimecast-Originator: redhat.com Content-Language: en-US, en-CA Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Rspam-User: X-Rspamd-Server: rspam10 X-Rspamd-Queue-Id: 9A23A1A000A X-Stat-Signature: 37uicupb1g168b53r3sjyo4kjyp3gonu X-HE-Tag: 1751477943-104934 X-HE-Meta: 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 vY6FROwS KIzcDRItZqVzKwPqOo6GcAnKzrmZ9qqpZeFIrU3JgsplZfzRU8zeoCage8cp6NnCmGWMXR70Egi2o+At5vBUKSZDjX9ZyLlpLBhnGFB9DkHTCifUw6c0ffL6G8unizVPWsqhsmIzanKz0rj1BljXA+02tu/RQ8X0SR7N+BNUHiHo3OurckR7nWZrAuXPvU0yC1QPGvCZNpZT0om7bhuDFLuLHXnF3W145nY5xcBsL+OC0vHyIZ/czKFSnjbsWL6rF9QHxGRz05kKl00ZI+KcoKDzoOJwajPfZmhl8e2983ZWQQJQiGMBIiGGLXBXZOr/GFq9+oXaoLmVweQ7tJGhNfRP7GyWAImTbhUx+sa3zavb1aUPGelcewwo8pgtqZdxKtaOfWAZ2fedHlYjacjwHVQSkEYzjvoMF+yXgLKb000sqggy+qu/gWLucY0Cv+GIJOKyZklGTqBkR0lar7tKve1bmQHDlcqiUvrTwAzLa67WsnL3FJCrCtMVWEES62dcY89LJTXx4jw+GVFFqsyJAhK+iWyyIXtpSZqiRfWzF9GwWoeU= 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 2025-07-02 02:25, Shivank Garg wrote: > > > On 6/26/2025 11:46 PM, Luiz Capitulino wrote: >> Currently, the call to folio_precise_page_mapcount() from kpage_read() >> can race with a folio split. When the race happens we trigger a >> VM_BUG_ON_FOLIO() in folio_entire_mapcount() (see splat below). >> >> This commit fixes this race by using snapshot_page() so that we >> retreive the folio mapcount using a folio snapshot. > > s/retreive/retrieve/ > checkpatch.pl would have flagged this. Thanks for pointing this out. I do run checkpatch.pl before sending patches, I don't know how I missed this. > > Rest looks good to me. > > Thanks, > Shivank >