From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=95.215.58.131 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793245305; b=KRE4AzK9U+WBehHn3d8yCDg6EpYuT7FkzzVPs0eNy81/WR9o87ucqWX9GDlNMyJU/bx9 RrwCUJQyg++JrSv0nUCAOIUxSt4KUiaePnqVkiQ5ESsza54Zr7PrQCv5ctJOUTh5UbDlo xG08KXRnmz5EL4s9j3fjVKYCpmavYhgFQp8lOC/1jfw77Qb62PhYrmx075mgG9jgM8Sfb XStgBLu0ArPpLOB/HTtxxrrEAlmYRHE11s9OwBuJcGgDz8grEOH/E3pVlnnI7VE9MaLOX p93Dp5Ip58XOY9AU11StlIgOEk7Nbc1q1hT+P7NSNr5xsprXQoICp0THL2hL7qv6Ppw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793245305; h=DMARC-Filter:X-Envelope-To:DKIM-Signature:X-Envelope-To:Received: X-Mizu-Trace-ID:X-Migadu-Flow:Content-Type:Mime-Version:Subject:From: In-Reply-To:Date:Cc:Content-Transfer-Encoding:Message-Id:References: To:X-Mailer; bh=SfpksgeRXYSviYFeyWHR5mqkoXxAslF2D1vkefSL3uw=; b=FaGO5BomQhPQxmUE6TSdPVtXLB4qwfTHld2XM2Z3ItlDENtq8YQireWAzqpFh6MpezQw FpFfuscceogqmjZtS3KVN4svi9i3iC9PZxDCQjMIRa5y9v6MDOywUXmUNVaGfh/WNgTwp INP8WE1zEh+dvmdO3p3TFM8dPZD7K2sh+QirQYpLXaiGggknQFs9TsBr2XK/8e2Sh9L8C AfyBkhnMWDE3a+EJErQed/r8qDNyjFHD8MAM20V97pnQCKDPNrExW6DvLsJoD5IXFcUPW 6CqCi8ctCMFzyHnHmffjkkPejj3WN+DND/nyia6l+URnrZFyZuPkgJUv2kUeDv4IBpg== 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=NxV2zbRI; arc=none smtp.remote-ip=95.215.58.131 Received: from mta1.migadu.com (out-131.mta1.migadu.com [95.215.58.131]) (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 6C1B8606A31D for ; Thu, 29 Oct 2026 03:41:44 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 6C1B8606A31D 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=NxV2zbRI X-Envelope-To: linux-kernel@vger.kernel.org DKIM-Signature: a=rsa-sha256; bh=SfpksgeRXYSviYFeyWHR5mqkoXxAslF2D1vkefSL3uw=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1793245302; v=1; x=1793850102; b=NxV2zbRImUBwLKbaCg/zWhoTSvWR2eSfQzp5or3rZukb97Uuetb23hfqkeJZqlF/85Uv7SQV 14s70j8cLPyw9jp/T7OE1W8F9ax2XsvgOtzbsLJ+K8zxGU3m0hjhT/SGpjNMU8Qv+D01RB5EhgF NXXHqIlq3oU27FdrMaowEbaY= X-Envelope-To: linux-kernel@vger.kernel.org Received: by mta10.migadu.com with ESMTPS id dc9967750c407019; Thu, 29 Oct 2026 03:41:42 +0000 X-Mizu-Trace-ID: dc9967750c407019 X-Migadu-Flow: FLOW_OUT Content-Type: text/plain; charset=us-ascii 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 (Mac OS X Mail 16.0 \(3901.100.1.1.12\)) Subject: Re: [PATCH 03/15] mm/hugetlb: preserve reservations when shrinking on HIGHMEM From: Muchun Song In-Reply-To: <20261028-fixes_hugetlb-v1-3-a0a033db180f@kernel.org> Date: Thu, 29 Oct 2026 11:41:12 +0800 Cc: Oscar Salvador , Naoya Horiguchi , Andrew Morton , Mel Gorman , Andy Whitcroft , Miaohe Lin , Michal Hocko , Rik van Riel , Hugh Dickins , Baolin Wang , Vivek Kasireddy , Dave Airlie , Jason Gunthorpe , Lorenzo Stoakes , "Liam R. Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Jonathan Corbet , Shuah Khan , Randy Dunlap , Peter Xu , Breno Leitao , Will Deacon , "Aneesh Kumar K.V" , Nick Piggin , Peter Zijlstra , Heiko Carstens , Vasily Gorbik , Alexander Gordeev , Christian Borntraeger , Sven Schnelle , Arnd Bergmann , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Gerd Hoffmann , linux-doc@vger.kernel.org, linux-arch@vger.kernel.org, linux-s390@vger.kernel.org Content-Transfer-Encoding: quoted-printable Message-Id: References: <20261028-fixes_hugetlb-v1-0-a0a033db180f@kernel.org> <20261028-fixes_hugetlb-v1-3-a0a033db180f@kernel.org> To: "David Hildenbrand (Arm)" X-Mailer: Apple Mail (2.3901.100.1.1.12) > On Oct 29, 2026, at 04:13, David Hildenbrand (Arm) = wrote: >=20 > try_to_free_low() drops the hugetlb_lock while freeing lowmem folios. > set_max_huge_pages() then resumes freeing folios using the > min_count computed before that unlock. Reservations created in between > can consequently lose their backing. >=20 > Collect lowmem folios on the caller's existing page_list instead. Keep > the hugetlb_lock held through both selection passes, and free the = combined > list at the caller's existing unlock point. >=20 > Likely not stable-worthy. >=20 > Fixes: 1121828a0c21 ("hugetlb: call update_and_free_page without = hugetlb_lock") > Signed-off-by: David Hildenbrand (Arm) Acked-by: Muchun Song Thanks.