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 34DF63ACF07 for ; Mon, 11 May 2026 08:07:21 +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=1778486842; cv=none; b=g6A4AoV6DpwHIhHSoXMbicid0LAiF754940jkkIJgKIMlsTd2qU/lbpPRPLoPl3z4Gz0ZXb7/Ar3FJfUwjVhi5p40rku2wki9o6P95dgz7HAQXx46iyiKIfLk4LI7hkOTdJBwKFd68WBs7MiPRbI06F6nT1qGyf6PGp3VCALH5M= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778486842; c=relaxed/simple; bh=Hv2TUTOaDojfumEKJhQdOH+FpyV8uE5bZuGwDm9nbkk=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=h2y9zjUCs19nsI/W34gElL0VerLt6K6eOC7mIkqZ9KKraSfOp16GlSDZHkKkUqh35ZVW7QavaSR8hF53Qj9Kr/YDzCEPsQoLBnNBl2oNvVYloGAC4Ki/jUFgF9rJ74Vpt8db4HPDEoS32hgtI3vgiJLlsjwex2VQgsEOAJyVKBA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=WD/VFGv8; 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="WD/VFGv8" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 04641C2BCB0; Mon, 11 May 2026 08:07:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1778486840; bh=Hv2TUTOaDojfumEKJhQdOH+FpyV8uE5bZuGwDm9nbkk=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=WD/VFGv8kN2/OyQghM2iYjaLD4ln290lKMK9comJhQ12fNWKOG9sRzzbUoZ2eBfG9 A1IXMNifd3PUEGDyWE5aXD/mvB88fD8ggMUuQY6xsrLaatGWCzHJhQGDnD7YGlw6Ke vgPI1wyEKCTCH4Ju3+UJHcus+ZP0C/UavhmhrdBzhRRlJnGLuFR4Fq7/DDg08nyDy3 Bc6BUsptQOLCD16SvO5CdItW6Rdkux3e4kWk3H0J5LEFHCpEFqoqVJxxRLAgDf7chs IY7Z1vfZD09fV+m2ragb80trDFPY3nyOP4t9yxSFwF2WBmIB3emZqRGe0w5wOItgo9 CXS2hCpLxSeCQ== Message-ID: <37a2531b-7b27-4574-838e-558ba310261b@kernel.org> Date: Mon, 11 May 2026 10:07:13 +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 v3 7/9] mm/swapfile: Add batched version of folio_put_swap To: Dev Jain , akpm@linux-foundation.org, ljs@kernel.org, hughd@google.com, chrisl@kernel.org, kasong@tencent.com Cc: riel@surriel.com, liam@infradead.org, vbabka@kernel.org, harry@kernel.org, jannh@google.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, qi.zheng@linux.dev, shakeel.butt@linux.dev, baohua@kernel.org, axelrasmussen@google.com, yuanchu@google.com, weixugc@google.com, rppt@kernel.org, surenb@google.com, mhocko@suse.com, baolin.wang@linux.alibaba.com, shikemeng@huaweicloud.com, nphamcs@gmail.com, bhe@redhat.com, youngjun.park@lge.com, pfalcato@suse.de, ryan.roberts@arm.com, anshuman.khandual@arm.com References: <20260506094504.2588857-1-dev.jain@arm.com> <20260506094504.2588857-8-dev.jain@arm.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: <20260506094504.2588857-8-dev.jain@arm.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 5/6/26 11:45, Dev Jain wrote: > Add folio_put_swap_pages to handle a batch of consecutive pages. Note > that folio_put_swap already can handle a subset of this: nr_pages == 1 and > nr_pages == folio_nr_pages(folio). Generalize this to any nr_pages. > > Currently we have a not-so-nice logic of passing in subpage == NULL if > we mean to exercise the logic on the entire folio, and subpage != NULL if > we want to exercise the logic on only that subpage. Remove this > indirection: the caller invokes folio_put_swap_pages() if it wants to > operate on a range of pages in the folio (i.e nr_pages may be anything > between 1 till folio_nr_pages()), and invokes folio_put_swap() if it > wants to operate on the entire folio. > > Signed-off-by: Dev Jain > --- [...] > > -static inline void folio_put_swap(struct folio *folio, struct page *page) > +static inline void folio_put_swap(struct folio *folio) > +{ > +} Same comment regarding common function. > + > +static inline void folio_put_swap_pages(struct folio *folio, struct page *page, > + unsigned long nr_pages) > { > } > > diff --git a/mm/swapfile.c b/mm/swapfile.c > index 28daf92839e77..ac576cc63b194 100644 > --- a/mm/swapfile.c > +++ b/mm/swapfile.c > @@ -1778,31 +1778,34 @@ int folio_dup_swap(struct folio *folio) > } > > /** > - * folio_put_swap() - Decrease swap count of swap entries of a folio. > + * folio_put_swap_pages() - Decrease swap count of swap entries of a folio. > * @folio: folio with swap entries bounded, must be in swap cache and locked. > - * @subpage: if not NULL, only decrease the swap count of this subpage. > + * @page: the first page in the folio to decrease the swap count for. > + * @nr_pages: the number of pages in the folio to decrease the swap count for. > * > * This won't free the swap slots even if swap count drops to zero, they are > * still pinned by the swap cache. User may call folio_free_swap to free them. > * Context: Caller must ensure the folio is locked and in the swap cache. > */ > -void folio_put_swap(struct folio *folio, struct page *subpage) > +void folio_put_swap_pages(struct folio *folio, struct page *page, > + unsigned long nr_pages) > { > swp_entry_t entry = folio->swap; > - unsigned long nr_pages = folio_nr_pages(folio); > struct swap_info_struct *si = __swap_entry_to_info(entry); > > VM_WARN_ON_FOLIO(!folio_test_locked(folio), folio); > VM_WARN_ON_FOLIO(!folio_test_swapcache(folio), folio); > > - if (subpage) { > - entry.val += folio_page_idx(folio, subpage); > - nr_pages = 1; > - } > + entry.val += folio_page_idx(folio, page); > > swap_put_entries_cluster(si, swp_offset(entry), nr_pages, false); > } > > +void folio_put_swap(struct folio *folio) > +{ > + folio_put_swap_pages(folio, folio_page(folio, 0), folio_nr_pages(folio)); > +} Same comment regarding kerneldoc :) ... and same comment that this definitely looks nicer. -- Cheers, David