From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=91.218.175.43 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793933631; b=raV3pR01ksw96+H/SJB+5KR1JGXWn8cuAygIFLnOR/Ymi4kK1huI4Z9y8hQl7xKSXq6a wWke3bNKzwsDGPadw1xWImIvUMCbdkMsrl6+IDy8ZgFRTVsRaqwJwdDXXx1mLwwTQ9cyX prZX06gdp1wXDKy3/ApZdsh9iN6QPeYHKvK5A9IXlZTR/BDPHQ99eOCoGsM2GL64jzKL9 ayIW9Q7YmRH7D/k0Nd7FnZIcjpnEueMZaTWy5R9zwVRPZXCEXaxYMlsoJmkNuRVe8PhvP ug74NBU09AGSoifILqPb8zNURw+2o+U3ydj4gkLC2/Pt634twQecKsojQzORnVE455Q== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793933631; h=DMARC-Filter:X-Envelope-To:DKIM-Signature:X-Envelope-To:Received: X-Mizu-Trace-ID:X-Migadu-Flow:From:To:Cc:Subject:Date:Message-ID: X-Mailer:In-Reply-To:References:MIME-Version:Content-Type: Content-Transfer-Encoding; bh=p/0b0eFgGy6/51XErR0gRmBAyxz+HU1vOEdRkX/jYa4=; b=ALU+NJYCBb5lJxL7rwpGJir3opD6iUmCBtldta9zrWuRaAxEYj2zM3VfbHFbkvKH21ik H6oaUaK71RwQAaFi/3htSoNbsWQvJcmaHOODHrH1kGMwvraYXR2eEHnKhy9dRkuoP5m1a kWBg+K6czdbMTryrI9ccFDF53IEWkpNP0DOUd8NDZlpy1ORBONt2BKfkTJwzQBUWW4DoJ cd1dOJLRsLMgECrjaJSP4KMqB6pS1u3JQeJxyQJMH8VD9Tb0rg906nKA9G8IT56c+BuK3 Exu81ieEmCE0JdaLKMuO7KogHNwPlsweryycgXF75A39URQ4Pbm/eIu/6y+ZnvatbwA== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=M9D9cqel; arc=none smtp.remote-ip=91.218.175.43 Received: from mta0.migadu.com (out-43.mta0.migadu.com [91.218.175.43]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 597C9606A31B for ; Fri, 6 Nov 2026 02:53:50 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 597C9606A31B Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=M9D9cqel X-Envelope-To: linux-kernel@vger.kernel.org DKIM-Signature: a=rsa-sha256; bh=p/0b0eFgGy6/51XErR0gRmBAyxz+HU1vOEdRkX/jYa4=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1793933628; v=1; x=1794538428; b=M9D9cqelqkYY1RFavnCPTWKYqchdbFaEOL/NPoxfxpdqWxDnWVBcD80nohsqwasPMXtUS0V8 4cMUG+IQm5nUilGuUux+Uh8CUg/YuwC0IAI9PTv0wC4puA6XnGTTSSXghUB61WjQMSVj/iqfvqA A/9cBch4N/fOzgxDDXZ+ipR4= X-Envelope-To: linux-kernel@vger.kernel.org Received: by smtp.migadu.com with ESMTPS id ea04818497cd00a3; Fri, 06 Nov 2026 02:53:48 +0000 X-Mizu-Trace-ID: ea04818497cd00a3 X-Migadu-Flow: FLOW_OUT From: Lance Yang To: david@kernel.org Cc: akpm@linux-foundation.org, ziy@nvidia.com, baolin.wang@linux.alibaba.com, hughd@google.com, liam@infradead.org, nico.pache@linux.dev, ryan.roberts@arm.com, dev.jain@arm.com, baohua@kernel.org, lance.yang@linux.dev, usama.arif@linux.dev, kas@kernel.org, zokeefe@google.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, mason@kernel.org, stable@vger.kernel.org Subject: Re: [PATCH] mm/khugepaged: don't map folios that are not uptodate in MADV_COLLAPSE Date: Fri, 6 Nov 2026 10:53:42 +0800 Message-ID: <20261106025342.18229-1-lance.yang@linux.dev> X-Mailer: git-send-email 2.49.0 In-Reply-To: <20261105-set_huge_pmd_uptodate-v1-1-a78d8a1b7117@kernel.org> References: <20261105-set_huge_pmd_uptodate-v1-1-a78d8a1b7117@kernel.org> 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-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit On Thu, Nov 05, 2026 at 07:16:44PM +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. > >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) >--- Nice work1 Reviewed-by: Lance Yang