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smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=ZrKPgrKE; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 50194606A31C; Wed, 11 Nov 2026 07:42:13 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=ZrKPgrKE Received: by smtp.kernel.org (Postfix) with ESMTPSA id EB16B1F00A05; Wed, 11 Nov 2026 07:42:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794382933; bh=173yMYYw7ZcLxgKiy0jg0nsIJyUryKORRWD5GlUnhak=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=ZrKPgrKEYhJ3yrT5CDmjH+84XqAPuC8dBR6n+o7uRVewZeDxtBU2esNhdUhlKZDGE 5/OF8Zp10h+LNC4wePwc242X5r0kA9voZ5MGuPjjE5dVW3bbYyojijX+SXp25q5yz7 pterk5xVQD/sj/5wJ8ps8IK2ZzriKEki/mJ5baXKQLA0xGsjApnODfEKbZLLYvQOzN +HjL8O3rKTiiWnl5jF5TLaKxnviMquCws9mMONye0NSZABK80mzBQnPuPWKNps/mzh InlthapJu41kW/sIjVNzmijcKciWkTZ/IObbE2c61U2ZW++XL25Arq/TAlS9Yu5PsE eDcz2l1F79syw== Message-ID: <0a971398-35d6-457c-81b4-0fd706da12b8@kernel.org> Date: Wed, 11 Nov 2026 08:42:06 +0100 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 v4 2/3] mm: gup: allow long-term pins of CMA-allocated HugeTLB folios To: Qi Zheng , muchun.song@linux.dev, osalvador@suse.de, akpm@linux-foundation.org, azpijr@gmail.com, lance.yang@linux.dev Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, Qi Zheng , stable@vger.kernel.org References: <503c9f6d869e3206c6fd591de962c3d619b73825.1794379433.git.zhengqi.arch@bytedance.com> 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 11/11/26 07:46, Qi Zheng wrote: > From: Qi Zheng > > Long-term pinning treats explicitly CMA-allocated HugeTLB folios as > unpinnable, causing unnecessary migration or pinning failures. > > These folios already own their CMA bitmap ranges, and memory blocks > overlapping CMA areas cannot be offlined. Allow HugeTLB folios with > HPG_cma to be pinned directly, including in ZONE_MOVABLE. You should really describe here what this patch does (move stuff) and why, and document why you decided to add more hugetlb hacks to core-MM that I absolutely hate. -- Cheers, David