From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 673E3478875 for ; Wed, 3 Jun 2026 12:03:16 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780488197; cv=none; b=tAL/QiSeIrTHB8ynXKWvF9EVfsbLQbkwDnaBwV4U9+AwfjwoZp/dFiWpJdLAqx/lrhWXX7V0hg0+AgaaH5szFEuOXqvR67bM2XPxGVIehxCJMegxxQ1vdyAakCIo1banZLGiEMZ2bgzbwMK/Tk14WPx5eZQO/pSNUbTPo7AQnhM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780488197; c=relaxed/simple; bh=YZ8vK3HC2sRMrekbQe5FpqwT3EUVVHK9LMOs49ACfSA=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=VnYVSmM9JMoZmV/MIFWEpXlca+JD9Ms2N9yI3rLjQWdm6e64dE67t2R6tcd3N9SpOTUVDjJQGy8kCvZjZ+U5XqAtqbbDg4PZEtkDdard3s7wzDistLFfQ20JFp1hZqdKOSFsa3WCmvdgR5tNet2trdA7LOwHDT3rFD1DD9c8cXQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=MoOFKsN7; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="MoOFKsN7" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 335FB1F00893; Wed, 3 Jun 2026 12:03:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1780488196; bh=5d4xRFPbP4Xfog839Pinex43yBWGt94sNmIfZBMoWz0=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=MoOFKsN7iFLlD2JoCjCFxOTgfgpJv1D0eJNUp4QNUqw6CrVwonSbGD7FY3NAOHMt/ FS/x8cDFTtbLvduRxbQSfG46Smzaj2FMiY6/0n0U9AL6vBrK88UIjX2pIUBUcu9pzw e+ekA7HEqgVcPf5yIl73tlAFj+pa7bMl9Jz/d8aBxHrHAIULOjJ1QV5Xl3DNtlQVa+ w5pFbuF5CdCdQ1I9drd6+2BKkBw06QtfPbClInhXPH6DTeREfESyTFBicevQ/YFFys rPCvapVR/0KQiFm1A235nhA2qDMQjleyJEIiKszfPAUz8RI3mkaxUPFHm2q08b38/v /ijZ94/SwkA4g== Date: Wed, 3 Jun 2026 13:03:06 +0100 From: Lorenzo Stoakes To: Baoquan He Cc: Matthew Wilcox , Jianyue Wu , Tal Zussman , Andrew Morton , Chris Li , Kairui Song , Kemeng Shi , Nhat Pham , Baoquan He , Barry Song , Youngjun Park , Qi Zheng , Shakeel Butt , Axel Rasmussen , Yuanchu Xie , Wei Xu , Johannes Weiner , David Hildenbrand , Michal Hocko , "Liam R. Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Hugh Dickins , Baolin Wang , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v3 2/3] mm: move folio LRU code out of swap Message-ID: References: <20260602-ch-swap-series-plus-folio-lru-cleanup-v3-0-5bbb567f8c99@gmail.com> <20260602-ch-swap-series-plus-folio-lru-cleanup-v3-2-5bbb567f8c99@gmail.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Wed, Jun 03, 2026 at 06:49:16PM +0800, Baoquan He wrote: > On 06/02/26 at 04:57pm, Matthew Wilcox wrote: > > On Tue, Jun 02, 2026 at 09:01:16AM +0800, Jianyue Wu wrote: > > > Rename mm/swap.c to mm/folio_lru.c so the filename better matches > > > the code's main responsibility. > > > > > > This keeps the implementation split from swap-specific code without > > > changing the published LRU helper interfaces. > > > > At the same time, we have Tal trying to split folio_wait.c out > > of filemap.c. https://lore.kernel.org/linux-mm/20260520-filemap-split-v1-0-c36ddc2b6cf2@columbia.edu/ > > > > I wonder if instead of folio_lru.c and folio_wait.c, we shouldn't simply > > have folio.c. Tal has 700 lines in his diffstat, you'll have about 1100 > > lines, so that's about 1800 llines which seems like a good size. > > There's some functions from mm/util.c that would fit nicely too -- > > folio_mapping(), folio_anon_vma(), folio_copy(), flush_dcache_folio() > > I think folio_lru.c and folio_wait.c are better than a single folio.c. > > A single folio.c with all of them would have no clear boundary for what > belongs there and what doesn't. For comparison, page_alloc.c isn't called > page.c (we have files called mm/page*.c). Well page_alloc.c doesn't only contain things that operate on struct page * right? Whereas folio.c is strictly operations literally performed on folios which seems like a good match to me. I find folio_lru.c and folio_wait.c far more difficult to figure out what goes where and there'll be a bunch of miscellaneous stuff all over the place. I vote for folio.c. > > > > > Other people have thoughts? > > Thanks, Lorenzo