From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 3B9743F20E2 for ; Wed, 1 Apr 2026 11:38:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775043517; cv=none; b=SRp+nFD+VEEKCG8Q1tVJfMOhmTtH4TI34LL8SG9ZdGgWWedOEubSXay4mH6QJwNBIrWOz5hT8OYm02/dGGo5eojHmn/OYrakqXI8xxpaXJm+f9S6AGduw1qATTtfN04f9CVF9nDMlSSuwBGK8lEuB8N1v9zbobQakTLV/6NZFsE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775043517; c=relaxed/simple; bh=12Rf9M+2EKOvcfXCBti89IrItim3hAHjNLiB9TnixCQ=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=B72rcKSFw56Vi8OnZkrn5WW6rOWxWZPL4hJkD1NBDyMZZn1CCs/tlOUCd2TIQiSL3Q0vjOSL60YsRqh38erfM8DCzZAV33fN2/CK/yiQdPK9YseYiP8mqiobFx+2EmJgS0orKB9bHnNc3xCChTOHBRAjiC7c7hrZ9rLWL0/q4W8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=eBskjXCM; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="eBskjXCM" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6EA01C4CEF7; Wed, 1 Apr 2026 11:38:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1775043516; bh=12Rf9M+2EKOvcfXCBti89IrItim3hAHjNLiB9TnixCQ=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=eBskjXCMmhOraxNGx+vZqaYVnU5l86LDX6mfpAY1dKa57LU8E8GKl1rCNXfnKyMg4 2912PlpapGG309BgU76kWmHig8RQDTa/B5VZQjXEwoonF3p3O0/auiYuokgn6m0o8P achUE6LNxyC3jVsCYP+4dMTq5MNtI52SIbyLmwS8hDbYqWeYpDO4QBH2X908dbtZC/ lfYkMN20zAo7Na+hKKWmAiB4AJWUVnQYV2Wayjt87WYgg692yVu8zhW31ETnGHKMD5 bT6kAoI9ecmVeELOCw/uWpbMvKim+tvo3SCub6PfpKI7Y67I5FC/eg0l2RM0F2AuDs BZ2pplF3Nri6Q== Message-ID: Date: Wed, 1 Apr 2026 13:38:31 +0200 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [syzbot] [mm?] WARNING in deferred_split_folio To: Lance Yang Cc: kartikey406@gmail.com, usama.arif@linux.dev, Liam.Howlett@oracle.com, ziy@nvidia.com, syzbot+a7067a757858ac8eb085@syzkaller.appspotmail.com, akpm@linux-foundation.org, baohua@kernel.org, baolin.wang@linux.alibaba.com, dev.jain@arm.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, ljs@kernel.org, npache@redhat.com, ryan.roberts@arm.com, syzkaller-bugs@googlegroups.com References: <38a347dc-8a1c-4d04-926d-7a6318e93ca2@kernel.org> <20260401113434.29369-1-lance.yang@linux.dev> From: "David Hildenbrand (Arm)" Content-Language: en-US Autocrypt: addr=david@kernel.org; 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charset=UTF-8 Content-Transfer-Encoding: 7bit On 4/1/26 13:34, Lance Yang wrote: > > On Wed, Apr 01, 2026 at 01:22:58PM +0200, David Hildenbrand (Arm) wrote: >> On 4/1/26 13:20, Lance Yang wrote: >>> >>> >>> Ouch, you're right, I was wrong - the trylock drop is a pre-existing >>> issue, not caused by the reorder ;) >>> >>> >>> Nice, LGTM! >>> >>> Given that the "trylock -> drop" behavior seems to exist already today, >>> do you think it's worth fixing that together with the reorder? >> >> I'd do it in a single shot if possible. > > ACK. > >> Can you craft something? (cc stable etc) > > certainly, will do! But commit[1] ("mm: migrate: requeue destination > folio on deferred split queue") is only in mm-stable now, not yet > upstream/stable ... It's tricky. The original commit will be backported to stable kernels, so we want also the fix to be backported to the same stable kernels. The commit id in mm-stable is "stable" now. -- Cheers, David