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 F31C929BDAD for ; Wed, 25 Feb 2026 08:49:34 +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=1772009375; cv=none; b=X8ayKGICIeu59EAE+07yTucIA63J3k1I/n7G0zpBw5XZQUSU0o5qk1VZgV3JH3QWBWQkcKWwjs++3a7WW/g8++xRgXByrtuJaZLC3fF89de8tk87nvcgARPdHYdLbdB2GDAaGx57vH/El2xUVjPHxArHiXBVzBCALYcWf3QlQUQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772009375; c=relaxed/simple; bh=iGFhhjWcf3fh9QEg/MjC3BBzlLN2UyZMh4sP5/wvP5E=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=kf1A2fd3Sj/yzeIBXFRbeDDep4MhM/tQd5sb4TtEIer6n6s8lcYuUXaX9F2HbUA+8I36Tof6rWhUpC/IFlI1dulV/hw6cHR9J8TQtXebc4x1znXpJbXZtoUtk3ciBvUZByhJj4E/nVV4nUnPG3rAiWKvBQNMV9mklYTlMJs9jak= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=SqcPgtBX; 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="SqcPgtBX" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7E351C116D0; Wed, 25 Feb 2026 08:49:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1772009374; bh=iGFhhjWcf3fh9QEg/MjC3BBzlLN2UyZMh4sP5/wvP5E=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=SqcPgtBX//yxnuuwt/5NH7ngw6V/v3KrTHUgBKjE6cU8V7B5uzOEa5xidi+zNpD5z nhv8EQEWsgWYCSmydRlN2I0Cb9buH9WZMz+uOW4bD4UYBjaNd2tUgJ+SJtpU/lrZyb 8Xh6N0YlNJp1FQiXqiQJxzeQbd2sIjyLcDNZH67QAzg9CaqkYYrfTMaPQjYFHbgT7f bn6nK5+5ZtxX5lZYJzbLoTw2YAhoEOueKwAfwJ+83XLQV6cC0p62v6DQ8Lf00wsbL6 6vkSEqzbFybuqL0LzaDv7v+FYhsE3i9aIrrok5PtFSYwsZE43QmQo4MuJQcMCewEfE Au+Pd6NoumD8A== Message-ID: Date: Wed, 25 Feb 2026 09:49:29 +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] mm/cma: move put_page_testzero() out of VM_WARN_ON in cma_release() To: Zi Yan , Andrew Morton Cc: Lorenzo Stoakes , "Liam R. Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Kefeng Wang , linux-mm@kvack.org, linux-kernel@vger.kernel.org, SeongJae Park , Ron Economos References: <20260225031231.2352011-1-ziy@nvidia.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: <20260225031231.2352011-1-ziy@nvidia.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 2/25/26 04:12, Zi Yan wrote: > When CONFIG_DEBUG_VM is not set, VM_WARN_ON is a NOP. Putting any statement > with side effect inside it is incorrect. Collect all !put_page_testzero() > results and check the sum using WARN instead after the loop. It restores > the same check in free_contig_range() before commit > e0c1326779cc ("mm: page_alloc: add alloc_contig_frozen_{range,pages}()"), > the commit prior to the Fixes one. > > Fixes: 9bda131c6093 ("mm: cma: add cma_alloc_frozen{_compound}()") > Reported-by: Ron Economos > Closes: https://lore.kernel.org/all/1b17c38f-30d3-4bb4-a7e1-e74b19ada885@w6rz.net/ > Suggested-by: Kefeng Wang > Signed-off-by: Zi Yan > --- > From V2: > - Collect !put_page_testzero() to get the right result. > > From V1: > - Collect all put_page_testzero() results and do a single WARN after the > loop. > > mm/cma.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/mm/cma.c b/mm/cma.c > index 94b5da468a7d..15cc0ae76c8e 100644 > --- a/mm/cma.c > +++ b/mm/cma.c > @@ -1013,6 +1013,7 @@ bool cma_release(struct cma *cma, const struct page *pages, > unsigned long count) > { > struct cma_memrange *cmr; > + unsigned long ret = 0; > unsigned long i, pfn; > > cmr = find_cma_memrange(cma, pages, count); > @@ -1021,7 +1022,9 @@ bool cma_release(struct cma *cma, const struct page *pages, > > pfn = page_to_pfn(pages); > for (i = 0; i < count; i++, pfn++) > - VM_WARN_ON(!put_page_testzero(pfn_to_page(pfn))); > + ret += !put_page_testzero(pfn_to_page(pfn)); > + > + WARN(ret, "%lu pages are still in use!\n", ret); > > __cma_release_frozen(cma, cmr, pages, count); > Thanks for taking care of the fix. Debugged-by: David Hildenbrand (Arm) Acked-by: David Hildenbrand (Arm) -- Cheers, David