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=1793927304; b=1sZdGaIAnboNbWs4y4K5yMYgK7Je6BA0J5tQmQJONObpOld/P9QOcd7YQ7QdDJaQgkNO g9JKWlkRp57/zReZe5H32gFwPgFSEvb9Hr7ctCin2MQ1/+cBW+z8O6uJ9V3wqYvMkMC+m GZPA1XjydhGCbVZTjig95BsXVnbsJIg7Ocilu6ON0Crz+BNZOuYQSF/HzMEIzc0QOELLl R1Lc6HZOOQFmI9T+7LFmdGIOBTO45ai3zdGm18vIhbnji8hn65EvNS0DtGawlX5Q1laE/ 5T2w5oPjIrKjJst5zjb9JFM5lzrr2hfrgD8nmLW36vfhWR0/7l1/Em6xzsAgCLoI4Ig== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793927304; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:MIME-Version:Content-Transfer-Encoding; bh=o15vljGBPrSpL6tMsJUEx5VdBCBrFc3GWWO7AUCavZk=; b=J+N0GEG3cC3HyHbb8sPtUSLCoI8gdthBbmXXmFmqU1zTLVVA2sRLZ1SxTr+Z+Yq4qn06 jVRUi0GFYwMxEEicOHvYx2Bw09LAcledRGgd6ROYbYwSwoNBbmyIAXOZgd3yY/b0AKzB8 oOLnX0JXNNKN4N0qHHzp6QPsQM+hmKheBeI+e0AVtKXT4ZKiSjDrWhCyTqXECv3vcAAS8 7QSwNB2yIO2lLT4TJAotG80XOXH8zhc36nCudzP3naNNCK5+d+RTzfHGRsCEMCzPWBrWH Ao1+2gsDlTFuSWjOgCsSSGgAi9alKhZerBXjLWVVY63P86kWlW0X7J3NJitA3j6ykEw== 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=eKlv0PJ4; 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 B0CC1606A31B; Fri, 6 Nov 2026 01:08:23 +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=eKlv0PJ4 Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8E4861F0089F; Fri, 6 Nov 2026 01:08:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793927303; bh=o15vljGBPrSpL6tMsJUEx5VdBCBrFc3GWWO7AUCavZk=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=eKlv0PJ4nSS4qNLgELPDMzv0j+nfNuim5X8z1T9q39haF7J6fKy0LDjwoQY4hKCpf fG5ozCC1vmpXNzqHinwk3z1P5OEX3Aq8IHwpy8ooneik6e+xd8An2RRUmeyiyMDSUv QJdtwY7eogm5qP11enkOnLaIkiXmFGG+Oi22Xa5otOOrVjy8LBQxfo6dINM4HFZfJ0 Th5hXodoj0PbDNFQveDNgj9HjI/h6lZ1PafW0JxjZ4qfFTAudhUNUuvXQ3esZ3p1wl c4YVRiRuC3g3oatsyXM5h19dUzKi0fE7HqWOrjZHgz2GpyXCQeoaCJ24wsQzzT+usT L10FfxLsfqhmw== From: SJ Park To: "David Hildenbrand (Arm)" Cc: SJ Park , Andrew Morton , Zi Yan , Baolin Wang , Hugh Dickins , "Liam R. Howlett" , Nico Pache , Ryan Roberts , Dev Jain , Barry Song , Lance Yang , Usama Arif , Kiryl Shutsemau , Zach O'Keefe , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Chris Mason , stable@vger.kernel.org Subject: Re: [PATCH] mm/khugepaged: don't map folios that are not uptodate in MADV_COLLAPSE Date: Thu, 5 Nov 2026 17:08:15 -0800 Message-ID: <20261106010815.96125-1-sj@kernel.org> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20261105-set_huge_pmd_uptodate-v1-1-a78d8a1b7117@kernel.org> References: X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit On Thu, 05 Nov 2026 19:16:44 +0100 "David Hildenbrand (Arm)" wrote: > madvise(MADV_COLLAPSE) can map PMD-sized pagecache folios that are not > uptodate. For example, shmem fallocate() can put such folios into the > page cache. > > collapse_file() already refuses to proceed with folios that are not > uptodate. Let's just do the same in try_collapse_pte_mapped_thp() and skip > such folios, leaving handling to the page faults. > > Note that collapse_file() effectively clears shmem folios through > shmem_get_folio(); let's keep this fix simple and simply let the page > fault path deal with that. Makes sense to me. > > Fixes: 34488399fa08 ("mm/madvise: add file and shmem support to MADV_COLLAPSE") > Reported-by: Chris Mason > Cc: stable@vger.kernel.org > Signed-off-by: David Hildenbrand (Arm) Reviewed-by: SJ Park Thanks, SJ [...]