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 CA1B026A0B9 for ; Wed, 26 Nov 2025 09:55:01 +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=1764150901; cv=none; b=C+wGIE5Hw9yWcsCXGIFfAgBME+6F4L4c00Rr0dWG8N16D+EXLwYwaaENx2inBYV4XH1WMV9YVQ/w97PO2crfay9KGJze02850FJCLfmra/uxjjO9tLVCWpuOD2BZI31yQPy6nccV4E3GogZUe0lUnFbjXTm4ZWfSrQ//xx6uKqk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764150901; c=relaxed/simple; bh=czA4ih43T4jn7HUj1yePBK4UCqlTH0yuZ/2smSik6Rs=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=L+mWbUkMLJFRrH3K93N+CfiqzQdvLqP/qFyCKOky5JGHWcN+uhUL2/DlKrhAc5jZ6/LJsXpxCLjrHsm4SNGeWgPV5CZYktVGJhLzxOnkLVoY/T9IX3OOnLOho0BarRe5deeC5A+eIpFjt0VgMFCzfHZ3c/uARGddCKvk8sxJG6Y= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Oqpgj7Ow; 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="Oqpgj7Ow" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 35452C113D0; Wed, 26 Nov 2025 09:54:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1764150901; bh=czA4ih43T4jn7HUj1yePBK4UCqlTH0yuZ/2smSik6Rs=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=Oqpgj7OwpnbjF3Gon/H88dlNFNGUz/S0mI9/Bj2EfEfLqOL73oGbbwy2jQk6SNdy+ BEZD8piEQuUs3QohS8fcr4YnDJs5kRkPiUY9DvfL/uag/KZ7wl0+hSdw9qK5RAjHzc MpnwcInM2atrOTxy2B4OMGmeDq3PKsm3284dR7wP76kIOI4+ALA3MreyVE3YBOolB2 bv0qxJvaTdL/t88wb7ONDGiAN+5HuGLNST6sIq69+bnmZZ1trt+0M4CQoLudCWxjH9 8kF9QOwNAoOEHncgd7OhLcmEdP+VPTjAoPgxCWzV/rbea5qiQNaIDIOyFuARIiIEQs bPUsS7jvgnC/w== Message-ID: <46d5090c-a6c5-41de-91c4-dacac58e1f9b@kernel.org> Date: Wed, 26 Nov 2025 10:54:55 +0100 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: [PATCH v3 1/4] mm/huge_memory: change folio_split_supported() to folio_check_splittable() To: Zi Yan , Lorenzo Stoakes Cc: Andrew Morton , Baolin Wang , "Liam R. Howlett" , Nico Pache , Ryan Roberts , Dev Jain , Barry Song , Lance Yang , Miaohe Lin , Naoya Horiguchi , Wei Yang , Balbir Singh , linux-mm@kvack.org, linux-kernel@vger.kernel.org References: <20251126035008.1919461-1-ziy@nvidia.com> <20251126035008.1919461-2-ziy@nvidia.com> From: "David Hildenbrand (Red Hat)" Content-Language: en-US In-Reply-To: <20251126035008.1919461-2-ziy@nvidia.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit > - /* > - * Folios that just got truncated cannot get split. Signal to the > - * caller that there was a race. > - * > - * TODO: this will also currently refuse shmem folios that are in the > - * swapcache. > - */ > - if (!is_anon && !folio->mapping) > - return -EBUSY; > - > if (new_order >= old_order) > return -EINVAL; > > - if (!folio_split_supported(folio, new_order, split_type, /* warn = */ true)) > - return -EINVAL; > - > - is_hzp = is_huge_zero_folio(folio); > - if (is_hzp) { > - pr_warn_ratelimited("Called split_huge_page for huge zero page\n"); > - return -EBUSY; As we are changing that case to a VM_WARN_ONCE(), is there some path where we might trigger that? I'm wondering about the split_huge_pages_all() function in particular. I guess the "!folio_test_lru(folio)" would protect us? Apart from that LGTM Acked-by: David Hildenbrand (Red Hat) -- Cheers David