From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=115.124.30.132 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793958068; b=bFV7dN8k6j7hAfNcCsK6k2iiMvr94a5h+NZcs0ugjR0ogfDs44j6kbYs4QON2uBIYxfv T0Yj39gNSWupugqBxC7QpojLoRPv6zyWwGJIhRkR/gvAKnK9OvdeZ4J71W4f7sRkgFZAY /cnXEEXOiG2A+3+EfQG79fupT+t8UTyL1oiKIUfeiWuxhDx10YVeqWFUk8ph9/Nuewlw7 nFZwxitH/CwVuMV9RtDA3l0GjJJ9fMJTRZOUJlQYIB9YJqZcLEqIAiqeRin23eTw/Q7D6 BAjErT74594wENdx8ka6elOw0PH4KbIowlS+KP+06H5Uhi7XXP6tBOFVrVLAPTo8CiQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793958068; h=DMARC-Filter:DKIM-Signature:X-Alimail-AntiSpam:Received:Message-ID: Date:MIME-Version:User-Agent:Subject:To:Cc:References:From: In-Reply-To:Content-Type:Content-Transfer-Encoding; bh=u++veeV2UEGzavVifT+Wy9EXLAeW8NwCQG/jN4kumaY=; b=0XPUKRcCUtR3ElOniGz6IQfwjgm37AjvKekgni+SWWoRZZc86wYHsY4vQYuT2uU/PQbv KulIsVfdDfTZyLBylWIwJFUezFRFWUF/9NpkJ1pmi5Ftmy9aaU66ELxGLP2qwrkZKQ70y ghArKdysYg+DIu0I5e1vgTwKSUpDZA1S4xecWuaZwYMQbFGzy1LiWuxCk+dHu0z1mDKZO ckAfYx+lRznVPT7mV6W8UB+nxY9N8noQ4ULSB84hMKP6soV3cql+81pzjThbEkH+M58t/ wUlxw+3XX28kBmZNiJnwm0kIPVmTbHD0mFgZ1+al0lbW2h2dNLzHQfZCWIBpr0nO7kg== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=linux.alibaba.com; spf=pass smtp.mailfrom=linux.alibaba.com; dkim=pass header.d=linux.alibaba.com header.i=@linux.alibaba.com header.a=rsa-sha256 header.s=default header.b=DkFigBwS; arc=none smtp.remote-ip=115.124.30.132 Received: from out30-132.freemail.mail.aliyun.com (out30-132.freemail.mail.aliyun.com [115.124.30.132]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E7939606A337 for ; Fri, 6 Nov 2026 09:41:06 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org E7939606A337 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.a=rsa-sha256 header.s=default header.b=DkFigBwS DKIM-Signature:v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.alibaba.com; s=default; t=1793958063; h=Message-ID:Date:MIME-Version:Subject:To:From:Content-Type; bh=u++veeV2UEGzavVifT+Wy9EXLAeW8NwCQG/jN4kumaY=; b=DkFigBwSugDesKuPqOGRhlGh/bpYVZBR8orKBKf1vZinqoGkmrFJAbKp9yP1uL2Vu/bdHFXzLPpeV/c6NMNoJq6hazGym3lWLYJzSQaIPgPC0tO4bG4IkPbN5DWXJIRKKvYe2EDQQsfzbOWJCVTKPFd20l/FNtY6GNurEB8oPDk= X-Alimail-AntiSpam:AC=PASS;BC=-1|-1;BR=01201311R161e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=maildocker-contentspam033032089153;MF=baolin.wang@linux.alibaba.com;NM=1;PH=DS;RN=14;SR=0;TI=SMTPD_---0XEBIttq_1793958062; Received: from 30.74.144.130(mailfrom:baolin.wang@linux.alibaba.com fp:SMTPD_---0XEBIttq_1793958062 cluster:ay36) by smtp.aliyun-inc.com; Fri, 06 Nov 2026 17:41:03 +0800 Message-ID: <76e89362-6c79-4231-9d0c-0688c026b9b0@linux.alibaba.com> Date: Fri, 6 Nov 2026 17:41:01 +0800 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 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2 1/3] Revert "mm/khugepaged: remove definition of struct khugepaged_mm_slot" To: "Lorenzo Stoakes (ARM)" , David Hildenbrand , Zi Yan , "Liam R. Howlett" , Nico Pache , Ryan Roberts , Dev Jain , Barry Song , Lance Yang , Usama Arif , Kiryl Shutsemau , Andrew Morton Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org References: <20261105-khugepaged-latency-fix-v2-0-4384bbfe4606@kernel.org> <20261105-khugepaged-latency-fix-v2-1-4384bbfe4606@kernel.org> From: Baolin Wang In-Reply-To: <20261105-khugepaged-latency-fix-v2-1-4384bbfe4606@kernel.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 11/6/26 4:57 AM, Lorenzo Stoakes (ARM) wrote: > This partially reverts commit b4c9ffb54b32 ("mm/khugepaged: remove > definition of struct khugepaged_mm_slot"), as a subsequent commit needs to > resurrect this type to store additional data alongside the mm_slot. > > The stated intent of the commit was to address a NULL check in > __khugepaged_exit(): > > mm_slot = mm_slot_entry(slot, struct khugepaged_mm_slot, slot); > > slot can be NULL and mm_slot_entry() is an alias for container_of(), so > this is container_of() a NULL value. > > This was benign as there was only 1 field in khugepaged_mm_slot (offsetting > NULL at 0 results in NULL), however it was right to fix this, so retain the > fix. > > It also unwrapped KMEM_CACHE() in khugepaged_init(). This was a mistake, > and was itself reverted in commit c14bdcc9f274 ("mm/khugepaged: use > KMEM_CACHE()"). Therefore, retain the KMEM_CACHE() form in this revert. > > Reviewed-by: David Hildenbrand (Arm) > Reviewed-by: Lance Yang > Signed-off-by: Lorenzo Stoakes (ARM) > --- LGTM. Reviewed-by: Baolin Wang