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From: Matthew Wilcox <willy@infradead.org>
To: Christoph Hellwig <hch@infradead.org>
Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org,
	linux-fsdevel@vger.kernel.org, linux-cachefs@redhat.com,
	linux-afs@lists.infradead.org
Subject: Re: [PATCH v6 00/27] Memory Folios
Date: Fri, 2 Apr 2021 15:49:15 +0100	[thread overview]
Message-ID: <20210402144915.GP351017@casper.infradead.org> (raw)
In-Reply-To: <20210402143755.GA1843620@infradead.org>

On Fri, Apr 02, 2021 at 03:37:55PM +0100, Christoph Hellwig wrote:
> On Thu, Apr 01, 2021 at 12:26:56PM +0100, Matthew Wilcox wrote:
> > On Thu, Apr 01, 2021 at 08:05:37AM +0100, Christoph Hellwig wrote:
> > > On Wed, Mar 31, 2021 at 07:47:01PM +0100, Matthew Wilcox (Oracle) wrote:
> > > >  - Mirror members of struct page (for pagecache / anon) into struct folio,
> > > >    so (eg) you can use folio->mapping instead of folio->page.mapping
> > > 
> > > Eww, why?
> > 
> > So that eventually we can rename page->mapping to page->_mapping and
> > prevent the bugs from people doing page->mapping on a tail page.  eg
> > https://lore.kernel.org/linux-mm/alpine.LSU.2.11.2103102214170.7159@eggly.anvils/
> 
> I'm not sure I like this.  This whole concept of structures that do need
> the same layout is very problematic, even with the safe guards you've
> added.  So if it was up to me I'd prefer the folio as a simple container
> as it was in the previous revisions.  At some point members should move
> from the page to the folio, but I'd rather do that over a shorter period
> an in targeted series.  We need the basic to go in first.

That was my original plan, but it'll be another round of churn, and I'm
not sure there'll be the appetite for it.  There's not a lot of appetite
for this round, and this one has measurable performance gains!



  reply	other threads:[~2021-04-02 14:49 UTC|newest]

Thread overview: 76+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-03-31 18:47 [PATCH v6 00/27] Memory Folios Matthew Wilcox (Oracle)
2021-03-31 18:47 ` [PATCH v6 01/27] mm: Introduce struct folio Matthew Wilcox (Oracle)
2021-04-06 12:29   ` Kirill A. Shutemov
2021-04-06 12:48     ` Matthew Wilcox
2021-04-06 14:21       ` Kirill A. Shutemov
2021-04-06 14:31       ` Christoph Hellwig
2021-04-06 14:40         ` Matthew Wilcox
2021-04-06 14:47           ` Christoph Hellwig
2021-04-06 14:55             ` Matthew Wilcox
2021-04-06 15:05               ` Christoph Hellwig
2021-04-06 16:25                 ` Matthew Wilcox
2021-04-07  6:09                   ` Christoph Hellwig
2021-04-08  9:01   ` Rasmus Villemoes
2021-03-31 18:47 ` [PATCH v6 02/27] mm: Add folio_pgdat and folio_zone Matthew Wilcox (Oracle)
2021-04-06 13:23   ` Christoph Hellwig
2021-03-31 18:47 ` [PATCH v6 03/27] mm/vmstat: Add functions to account folio statistics Matthew Wilcox (Oracle)
2021-04-06 13:25   ` Christoph Hellwig
2021-03-31 18:47 ` [PATCH v6 04/27] mm/debug: Add VM_BUG_ON_FOLIO and VM_WARN_ON_ONCE_FOLIO Matthew Wilcox (Oracle)
2021-04-06 13:26   ` Christoph Hellwig
2021-03-31 18:47 ` [PATCH v6 05/27] mm: Add folio reference count functions Matthew Wilcox (Oracle)
2021-04-06 13:30   ` Christoph Hellwig
2021-03-31 18:47 ` [PATCH v6 06/27] mm: Add put_folio Matthew Wilcox (Oracle)
2021-04-06 13:31   ` Christoph Hellwig
2021-03-31 18:47 ` [PATCH v6 07/27] mm: Add get_folio Matthew Wilcox (Oracle)
2021-04-06 13:32   ` Christoph Hellwig
2021-03-31 18:47 ` [PATCH v6 08/27] mm: Create FolioFlags Matthew Wilcox (Oracle)
2021-04-06 13:34   ` Christoph Hellwig
2021-03-31 18:47 ` [PATCH v6 09/27] mm: Handle per-folio private data Matthew Wilcox (Oracle)
2021-04-06 13:37   ` Christoph Hellwig
2021-03-31 18:47 ` [PATCH v6 10/27] mm/filemap: Add folio_index, folio_file_page and folio_contains Matthew Wilcox (Oracle)
2021-04-06 13:39   ` Christoph Hellwig
2021-03-31 18:47 ` [PATCH v6 11/27] mm/filemap: Add folio_next_index Matthew Wilcox (Oracle)
2021-04-06 13:40   ` Christoph Hellwig
2021-03-31 18:47 ` [PATCH v6 12/27] mm/filemap: Add folio_offset and folio_file_offset Matthew Wilcox (Oracle)
2021-04-06 13:42   ` Christoph Hellwig
2021-03-31 18:47 ` [PATCH v6 13/27] mm/util: Add folio_mapping and folio_file_mapping Matthew Wilcox (Oracle)
2021-04-06 13:45   ` Christoph Hellwig
2021-03-31 18:47 ` [PATCH v6 14/27] mm: Add folio_mapcount Matthew Wilcox (Oracle)
2021-04-06 13:46   ` Christoph Hellwig
2021-03-31 18:47 ` [PATCH v6 15/27] mm/memcg: Add folio wrappers for various functions Matthew Wilcox (Oracle)
2021-04-06 13:48   ` Christoph Hellwig
2021-03-31 18:47 ` [PATCH v6 16/27] mm/filemap: Add unlock_folio Matthew Wilcox (Oracle)
2021-04-06 13:51   ` Christoph Hellwig
2021-03-31 18:47 ` [PATCH v6 17/27] mm/filemap: Add lock_folio Matthew Wilcox (Oracle)
2021-04-06 13:52   ` Christoph Hellwig
2021-03-31 18:47 ` [PATCH v6 18/27] mm/filemap: Add lock_folio_killable Matthew Wilcox (Oracle)
2021-04-06 13:53   ` Christoph Hellwig
2021-03-31 18:47 ` [PATCH v6 19/27] mm/filemap: Add __lock_folio_async Matthew Wilcox (Oracle)
2021-04-06 13:55   ` Christoph Hellwig
2021-03-31 18:47 ` [PATCH v6 20/27] mm/filemap: Add __lock_folio_or_retry Matthew Wilcox (Oracle)
2021-04-06 13:57   ` Christoph Hellwig
2021-03-31 18:47 ` [PATCH v6 21/27] mm/filemap: Add wait_on_folio_locked Matthew Wilcox (Oracle)
2021-04-06 14:11   ` Christoph Hellwig
2021-03-31 18:47 ` [PATCH v6 22/27] mm/filemap: Add end_folio_writeback Matthew Wilcox (Oracle)
2021-04-06 14:13   ` Christoph Hellwig
2021-03-31 18:47 ` [PATCH v6 23/27] mm/writeback: Add wait_on_folio_writeback Matthew Wilcox (Oracle)
2021-04-06 14:15   ` Christoph Hellwig
2021-03-31 18:47 ` [PATCH v6 24/27] mm/writeback: Add wait_for_stable_folio Matthew Wilcox (Oracle)
2021-04-06 14:18   ` Christoph Hellwig
2021-03-31 18:47 ` [PATCH v6 25/27] mm/filemap: Convert wait_on_page_bit to wait_on_folio_bit Matthew Wilcox (Oracle)
2021-04-06 14:19   ` Christoph Hellwig
2021-03-31 18:47 ` [PATCH v6 26/27] mm/filemap: Convert wake_up_page_bit to wake_up_folio_bit Matthew Wilcox (Oracle)
2021-04-06 14:23   ` Christoph Hellwig
2021-03-31 18:47 ` [PATCH v6 27/27] mm/filemap: Convert page wait queues to be folios Matthew Wilcox (Oracle)
2021-04-06 14:25   ` Christoph Hellwig
2021-04-01  7:05 ` [PATCH v6 00/27] Memory Folios Christoph Hellwig
2021-04-01 11:26   ` Matthew Wilcox
2021-04-01 12:28     ` Jason Gunthorpe
2021-04-01 12:52       ` Matthew Wilcox
2021-04-01 13:30         ` Jason Gunthorpe
2021-04-02 14:37     ` Christoph Hellwig
2021-04-02 14:49       ` Matthew Wilcox [this message]
2021-04-03  0:31 ` Kent Overstreet
2021-04-05 19:14 ` Jeff Layton
2021-04-05 19:31   ` Matthew Wilcox
2021-04-06 15:14     ` Jeff Layton

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