From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-174.mta1.migadu.com (out-174.mta1.migadu.com [95.215.58.174]) (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 8A9E3372661 for ; Wed, 1 Apr 2026 11:41:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.174 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775043682; cv=none; b=lcFRCbCVwimYhzYh1T+bH9FXcw8pfbDvOpVpWmSOEFLKq+7pk4ZfI8sZGFIAvb7wSdB2YEroAYxoDm52zb/MnhwWVuoP0skGyhgVyl+8l1Lb9Ylj2N7+NTKzOmr44ZukAIrlAPrGp10D7vhSHMVlPVLlj0Y3ddZH+IVbPHdOusw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775043682; c=relaxed/simple; bh=7K8P2ibDYnYINkm1dXGZk5zRyUOfDk0WCEAiRvMh23E=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=J/CJ9ERsO0uijtmO+AA3gVc0h8iNnbM2HnfGiJeXgGYq0DRP6pHG8SlJXXRYuOQR17XC1IrellE7YmMl/ebtvMw+GtwQRsmmOSyRdscHa0s7cJ5xxZh+ZtxaZkt0dt7DXKAnJw9AWkora6rsza2wBuXPQzmfhRa3vsnRHTidVm8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=Z5igplaL; arc=none smtp.client-ip=95.215.58.174 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) header.d=linux.dev header.i=@linux.dev header.b="Z5igplaL" Message-ID: <7176f8a2-8830-4fe9-b00e-fae67e2ac81d@linux.dev> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1775043678; 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=b13KGvyLogtVdL0iQImh9QPPdc4i4Vx371Gruxsxw98=; b=Z5igplaLxy29+thTrFyJCAfRPzl/HshpDrD3dnFTkZn6ogDxQZJiNOfhfblTCiY3+NctKA QE3k2hPAWTAjw6fzQcLS3PYLC2TLC0y8Xut0V0MixZIRyTgUus6yyUnSvKogvtYveleKNp YoI5uDwS+YFCHEG2lTtSzkWl6NnW1r4= Date: Wed, 1 Apr 2026 19:41:04 +0800 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Subject: Re: [syzbot] [mm?] WARNING in deferred_split_folio Content-Language: en-US To: "David Hildenbrand (Arm)" 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> X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Lance Yang In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Migadu-Flow: FLOW_OUT On 2026/4/1 19:38, David Hildenbrand (Arm) wrote: > 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. Emm... Not a big deal, I guess. We can always submit a stable backport once that fix gets merged into stable :D