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 8AED12E22B5; Tue, 14 Apr 2026 08:15:04 +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=1776154504; cv=none; b=e7A/meGx94OUzNqLxvx3+iABZyhjyYKxz+0CV5BXwuL2rF0wkVqaC6aoCO7mHujuV2Olm5ugaiswbWQ8xqekA+qNP/P++tbCxBRS2LvFe1sYRLp6tZZKXWROOpcutvUa9k/peoQ/HsN37MZ3NZpQahVpeK40TcabtJ8kUTpcytI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776154504; c=relaxed/simple; bh=i+61MYwPhyBU9c2P6PAHwEwjeACa/kQ2i7soG6qp95o=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=dO/YDFYSLaOm57N+MSrizbW2KedB7X0o/S/0joiJgxfyRat9r0EytKydaABPXno2xhBGSoHDKiFy5vYR2jA3RRONG1gyr1uhaTJxAcro267JR0A8pSp2o/3ovInOpTVnvGZhsItlZDPb4YFHG1Y+Oq2AeHvw2K8oLG82QoUlyS0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=OMCkt5Vj; 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="OMCkt5Vj" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6AD84C19425; Tue, 14 Apr 2026 08:15:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1776154504; bh=i+61MYwPhyBU9c2P6PAHwEwjeACa/kQ2i7soG6qp95o=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=OMCkt5VjSw6kunvIIqZ5OYLfnoIvIQ8TBCG06q1EoPeLYvh7fia6rjTK7MCT1AYhO mwz/6KJOe98IMgnm3lpvLQ5tKWZKZ2QGtjhl5F/IMgm/rKKyvjYsFwubauGFtR+/p9 GsHxJQuE3R4+sq7g47rBbDOpxpHIL9ZPoGYKjaheuLzvY/6xHLh7z/MoxMCgo9zvhi +CmhxEARIuy5IbMpPW1d5e7FJN+faRgWl8LAy5RBqoKYEeCYWwZnfvLBJrNSEc4eU6 gLh48F3XacTq72Ikk6Nwfe6GSMfMNQTXlOYflZUshbcfStdNlNYa9CyEqDC7tJjWQr b1FrDQTMndxiQ== Message-ID: Date: Tue, 14 Apr 2026 10:14:57 +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: [PATCH 1/2] mm: fix mmap errno value when MAP_DROPPABLE is not supported To: anthony.yznaga@oracle.com, Andrew Morton Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, ljs@kernel.org, Liam.Howlett@oracle.com, vbabka@kernel.org, rppt@kernel.org, surenb@google.com, mhocko@suse.com, jannh@google.com, pfalcato@suse.de, Jason@zx2c4.com, shuah@kernel.org References: <20260402003417.438037-1-anthony.yznaga@oracle.com> <20260402003417.438037-2-anthony.yznaga@oracle.com> <20260401174440.0f85ea303f0a027b50d99e5d@linux-foundation.org> <2f59c4e3-303f-4e13-a0a5-e1b5e5c1a37f@oracle.com> <43370425-00b0-4853-bc82-63064eae2b8e@oracle.com> From: "David Hildenbrand (Arm)" Content-Language: en-US Autocrypt: addr=david@kernel.org; keydata= xsFNBFXLn5EBEAC+zYvAFJxCBY9Tr1xZgcESmxVNI/0ffzE/ZQOiHJl6mGkmA1R7/uUpiCjJ dBrn+lhhOYjjNefFQou6478faXE6o2AhmebqT4KiQoUQFV4R7y1KMEKoSyy8hQaK1umALTdL QZLQMzNE74ap+GDK0wnacPQFpcG1AE9RMq3aeErY5tujekBS32jfC/7AnH7I0v1v1TbbK3Gp XNeiN4QroO+5qaSr0ID2sz5jtBLRb15RMre27E1ImpaIv2Jw8NJgW0k/D1RyKCwaTsgRdwuK Kx/Y91XuSBdz0uOyU/S8kM1+ag0wvsGlpBVxRR/xw/E8M7TEwuCZQArqqTCmkG6HGcXFT0V9 PXFNNgV5jXMQRwU0O/ztJIQqsE5LsUomE//bLwzj9IVsaQpKDqW6TAPjcdBDPLHvriq7kGjt WhVhdl0qEYB8lkBEU7V2Yb+SYhmhpDrti9Fq1EsmhiHSkxJcGREoMK/63r9WLZYI3+4W2rAc UucZa4OT27U5ZISjNg3Ev0rxU5UH2/pT4wJCfxwocmqaRr6UYmrtZmND89X0KigoFD/XSeVv jwBRNjPAubK9/k5NoRrYqztM9W6sJqrH8+UWZ1Idd/DdmogJh0gNC0+N42Za9yBRURfIdKSb B3JfpUqcWwE7vUaYrHG1nw54pLUoPG6sAA7Mehl3nd4pZUALHwARAQABzS5EYXZpZCBIaWxk ZW5icmFuZCAoQ3VycmVudCkgPGRhdmlkQGtlcm5lbC5vcmc+wsGQBBMBCAA6AhsDBQkmWAik AgsJBBUKCQgCFgICHgUCF4AWIQQb2cqtc1xMOkYN/MpN3hD3AP+DWgUCaYJt/AIZAQAKCRBN 3hD3AP+DWriiD/9BLGEKG+N8L2AXhikJg6YmXom9ytRwPqDgpHpVg2xdhopoWdMRXjzOrIKD g4LSnFaKneQD0hZhoArEeamG5tyo32xoRsPwkbpIzL0OKSZ8G6mVbFGpjmyDLQCAxteXCLXz ZI0VbsuJKelYnKcXWOIndOrNRvE5eoOfTt2XfBnAapxMYY2IsV+qaUXlO63GgfIOg8RBaj7x 3NxkI3rV0SHhI4GU9K6jCvGghxeS1QX6L/XI9mfAYaIwGy5B68kF26piAVYv/QZDEVIpo3t7 /fjSpxKT8plJH6rhhR0epy8dWRHk3qT5tk2P85twasdloWtkMZ7FsCJRKWscm1BLpsDn6EQ4 jeMHECiY9kGKKi8dQpv3FRyo2QApZ49NNDbwcR0ZndK0XFo15iH708H5Qja/8TuXCwnPWAcJ DQoNIDFyaxe26Rx3ZwUkRALa3iPcVjE0//TrQ4KnFf+lMBSrS33xDDBfevW9+Dk6IISmDH1R HFq2jpkN+FX/PE8eVhV68B2DsAPZ5rUwyCKUXPTJ/irrCCmAAb5Jpv11S7hUSpqtM/6oVESC 3z/7CzrVtRODzLtNgV4r5EI+wAv/3PgJLlMwgJM90Fb3CB2IgbxhjvmB1WNdvXACVydx55V7 LPPKodSTF29rlnQAf9HLgCphuuSrrPn5VQDaYZl4N/7zc2wcWM7BTQRVy5+RARAA59fefSDR 9nMGCb9LbMX+TFAoIQo/wgP5XPyzLYakO+94GrgfZjfhdaxPXMsl2+o8jhp/hlIzG56taNdt VZtPp3ih1AgbR8rHgXw1xwOpuAd5lE1qNd54ndHuADO9a9A0vPimIes78Hi1/yy+ZEEvRkHk /kDa6F3AtTc1m4rbbOk2fiKzzsE9YXweFjQvl9p+AMw6qd/iC4lUk9g0+FQXNdRs+o4o6Qvy iOQJfGQ4UcBuOy1IrkJrd8qq5jet1fcM2j4QvsW8CLDWZS1L7kZ5gT5EycMKxUWb8LuRjxzZ 3QY1aQH2kkzn6acigU3HLtgFyV1gBNV44ehjgvJpRY2cC8VhanTx0dZ9mj1YKIky5N+C0f21 zvntBqcxV0+3p8MrxRRcgEtDZNav+xAoT3G0W4SahAaUTWXpsZoOecwtxi74CyneQNPTDjNg azHmvpdBVEfj7k3p4dmJp5i0U66Onmf6mMFpArvBRSMOKU9DlAzMi4IvhiNWjKVaIE2Se9BY FdKVAJaZq85P2y20ZBd08ILnKcj7XKZkLU5FkoA0udEBvQ0f9QLNyyy3DZMCQWcwRuj1m73D sq8DEFBdZ5eEkj1dCyx+t/ga6x2rHyc8Sl86oK1tvAkwBNsfKou3v+jP/l14a7DGBvrmlYjO 59o3t6inu6H7pt7OL6u6BQj7DoMAEQEAAcLBfAQYAQgAJgIbDBYhBBvZyq1zXEw6Rg38yk3e EPcA/4NaBQJonNqrBQkmWAihAAoJEE3eEPcA/4NaKtMQALAJ8PzprBEXbXcEXwDKQu+P/vts IfUb1UNMfMV76BicGa5NCZnJNQASDP/+bFg6O3gx5NbhHHPeaWz/VxlOmYHokHodOvtL0WCC 8A5PEP8tOk6029Z+J+xUcMrJClNVFpzVvOpb1lCbhjwAV465Hy+NUSbbUiRxdzNQtLtgZzOV Zw7jxUCs4UUZLQTCuBpFgb15bBxYZ/BL9MbzxPxvfUQIPbnzQMcqtpUs21CMK2PdfCh5c4gS sDci6D5/ZIBw94UQWmGpM/O1ilGXde2ZzzGYl64glmccD8e87OnEgKnH3FbnJnT4iJchtSvx yJNi1+t0+qDti4m88+/9IuPqCKb6Stl+s2dnLtJNrjXBGJtsQG/sRpqsJz5x1/2nPJSRMsx9 5YfqbdrJSOFXDzZ8/r82HgQEtUvlSXNaXCa95ez0UkOG7+bDm2b3s0XahBQeLVCH0mw3RAQg r7xDAYKIrAwfHHmMTnBQDPJwVqxJjVNr7yBic4yfzVWGCGNE4DnOW0vcIeoyhy9vnIa3w1uZ 3iyY2Nsd7JxfKu1PRhCGwXzRw5TlfEsoRI7V9A8isUCoqE2Dzh3FvYHVeX4Us+bRL/oqareJ CIFqgYMyvHj7Q06kTKmauOe4Nf0l0qEkIuIzfoLJ3qr5UyXc2hLtWyT9Ir+lYlX9efqh7mOY qIws/H2t In-Reply-To: <43370425-00b0-4853-bc82-63064eae2b8e@oracle.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit On 4/14/26 02:43, anthony.yznaga@oracle.com wrote: > > On 4/2/26 4:13 PM, anthony.yznaga@oracle.com wrote: >> >> On 4/2/26 12:17 AM, David Hildenbrand (Arm) wrote: >>> >>> Acked-by: David Hildenbrand (Arm) >>> >>> >>> But >>> >>> ~/git/linux/mm$ git grep ENOTSUPP >>> hugetlb_vmemmap.c:                      ret = -ENOTSUPP; >>> mmap.c:                         return -ENOTSUPP; >>> >>> >>> Should we fix up the other one as well? >>> >> I'm looking into this. It's returned for the case where vmemmap >> mappings cannot be split/freed because they are self-hosted due to >> memory hotplug. Many callers end up ignoring the error, but there may >> be a way for it to be propagated to userspace as the errno for a >> failed write to a sysfs file. > > To follow up on this, the ENOTSUPP returned by vmemmap_pmd_entry is not > propagated to user space.  It is used internally to ensure > HPG_vmemmap_optimized is cleared for a hugetlb folio when HVO cannot be > applied due to the vmemmap memory being self-hosted. Thanks for checking, it indeed propagates a bit but never seems to leave the file. It would probably still be better to just clean that one up as well. -- Cheers, David