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From: Dan Williams <dan.j.williams@intel.com>
To: Matthew Wilcox <willy@infradead.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>,
	"Darrick J. Wong" <djwong@kernel.org>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	linux-mm <linux-mm@kvack.org>,
	linux-fsdevel <linux-fsdevel@vger.kernel.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	Andrew Morton <akpm@linux-foundation.org>
Subject: Re: [GIT PULL] Memory folios for v5.15
Date: Fri, 27 Aug 2021 14:41:11 -0700	[thread overview]
Message-ID: <CAA9_cmeVK9S2e8ECh3dTaNzUgQHC8uo7DBhENgnvoR3s+w-2Mg@mail.gmail.com> (raw)
In-Reply-To: <YSkyjcX9Ih816mB9@casper.infradead.org>

On Fri, Aug 27, 2021 at 11:47 AM Matthew Wilcox <willy@infradead.org> wrote:
>
> On Fri, Aug 27, 2021 at 10:07:16AM -0400, Johannes Weiner wrote:
> > We have the same thoughts in MM and growing memory sizes. The DAX
> > stuff said from the start it won't be built on linear struct page
> > mappings anymore because we expect the memory modules to be too big to
> > manage them with such fine-grained granularity.
>
> Well, I did.  Then I left Intel, and Dan took over.  Now we have a struct
> page for each 4kB of PMEM.  I'm not particularly happy about this change
> of direction.

Page-less DAX left more problems than it solved. Meanwhile,
ZONE_DEVICE has spawned other useful things like peer-to-peer DMA.

I am more encouraged by efforts to make the 'struct page' overhead
disappear, first from Muchun Song for hugetlbfs and recently Joao
Martins for device-dax.  If anything, I think 'struct page' for PMEM /
DAX *strengthens* the case for folios / better mechanisms to reduce
the overhead of tracking 4K pages.

  reply	other threads:[~2021-08-27 21:41 UTC|newest]

Thread overview: 175+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-08-23 19:01 [GIT PULL] Memory folios for v5.15 Matthew Wilcox
2021-08-23 21:26 ` Johannes Weiner
2021-08-23 22:06   ` Linus Torvalds
2021-08-23 22:06     ` Linus Torvalds
2021-08-24  2:20     ` Matthew Wilcox
2021-08-24 13:04     ` Matthew Wilcox
2021-08-23 22:15   ` Matthew Wilcox
2021-08-24 18:32     ` Johannes Weiner
2021-08-24 18:59       ` Linus Torvalds
2021-08-24 18:59         ` Linus Torvalds
2021-08-25  6:39         ` Christoph Hellwig
2021-08-24 19:44       ` Matthew Wilcox
2021-08-25 15:13         ` Johannes Weiner
2021-08-26  0:45           ` Darrick J. Wong
2021-08-27 14:07             ` Johannes Weiner
2021-08-27 18:44               ` Matthew Wilcox
2021-08-27 21:41                 ` Dan Williams [this message]
2021-08-27 21:41                   ` Dan Williams
2021-08-27 21:49                   ` Matthew Wilcox
2021-08-30 17:32                 ` Johannes Weiner
2021-08-30 18:22                   ` Matthew Wilcox
2021-08-30 20:27                     ` Johannes Weiner
2021-08-30 21:38                       ` Matthew Wilcox
2021-08-31 17:40                         ` Vlastimil Babka
2021-09-01 17:43                         ` Johannes Weiner
2021-09-02 15:13                           ` Zi Yan
2021-09-06 14:00                             ` Vlastimil Babka
2021-08-31 18:50                       ` Eric W. Biederman
2021-08-31 18:50                         ` Eric W. Biederman
2021-08-26  8:58         ` David Howells
2021-08-27 10:03           ` Johannes Weiner
2021-08-27 12:05             ` Matthew Wilcox
2021-08-27 10:49           ` David Howells
2021-08-24 15:54   ` David Howells
2021-08-24 17:56     ` Matthew Wilcox
2021-08-24 18:26       ` Linus Torvalds
2021-08-24 18:26         ` Linus Torvalds
2021-08-24 18:29         ` Linus Torvalds
2021-08-24 18:29           ` Linus Torvalds
2021-08-24 19:26           ` Theodore Ts'o
2021-08-24 19:34           ` David Howells
2021-08-24 20:02             ` Theodore Ts'o
2021-08-24 21:32             ` David Howells
2021-08-25 12:08               ` Jeff Layton
2021-08-24 19:01         ` Matthew Wilcox
2021-08-24 19:11           ` Linus Torvalds
2021-08-24 19:11             ` Linus Torvalds
2021-08-24 19:23             ` Matthew Wilcox
2021-08-24 19:44               ` Theodore Ts'o
2021-08-24 20:00                 ` Matthew Wilcox
2021-08-25  6:32                 ` Christoph Hellwig
2021-08-25  9:01                   ` Rasmus Villemoes
2021-08-26  6:32                     ` Amir Goldstein
2021-08-26  6:32                       ` Amir Goldstein
2021-08-25 12:03                   ` Jeff Layton
2021-08-25 12:03                     ` Jeff Layton
2021-08-26  0:59                     ` Darrick J. Wong
2021-08-26  4:02                   ` Nicholas Piggin
2021-09-01 12:58                 ` Mike Rapoport
2021-08-24 19:35             ` David Howells
2021-08-24 20:35               ` Vlastimil Babka
2021-08-24 20:40                 ` Vlastimil Babka
2021-08-24 19:11         ` David Howells
2021-08-24 19:25           ` Linus Torvalds
2021-08-24 19:25             ` Linus Torvalds
2021-08-24 19:38             ` Linus Torvalds
2021-08-24 19:38               ` Linus Torvalds
2021-08-24 19:48               ` Linus Torvalds
2021-08-24 19:48                 ` Linus Torvalds
2021-08-26 17:18                 ` Matthew Wilcox
2021-08-24 19:59             ` David Howells
2021-10-05 13:52   ` Matthew Wilcox
2021-10-05 17:29     ` Johannes Weiner
2021-10-05 17:32       ` David Hildenbrand
2021-10-05 18:30       ` Matthew Wilcox
2021-10-05 19:56         ` Jason Gunthorpe
2021-08-28  3:29 ` Matthew Wilcox
2021-09-09 12:43 ` Christoph Hellwig
2021-09-09 13:56   ` Vlastimil Babka
2021-09-09 18:16     ` Johannes Weiner
2021-09-09 18:44       ` Matthew Wilcox
2021-09-09 22:03         ` Johannes Weiner
2021-09-09 22:48           ` Matthew Wilcox
2021-09-09 19:17     ` John Hubbard
2021-09-09 19:23       ` Matthew Wilcox
2021-09-10 20:16 ` Folio discussion recap Kent Overstreet
2021-09-11  1:23   ` Kirill A. Shutemov
2021-09-13 11:32     ` Michal Hocko
2021-09-13 18:12       ` Johannes Weiner
2021-09-15 15:40   ` Johannes Weiner
2021-09-15 17:55     ` Damian Tometzki
2021-09-16  2:58     ` Darrick J. Wong
2021-09-16 16:54       ` Johannes Weiner
2021-09-17  5:24         ` Dave Chinner
2021-09-17  7:18           ` Christoph Hellwig
2021-09-17 16:31           ` Johannes Weiner
2021-09-17 20:57             ` Kirill A. Shutemov
2021-09-17 21:17               ` Kent Overstreet
2021-09-17 22:02                 ` Kirill A. Shutemov
2021-09-17 22:21                   ` Kent Overstreet
2021-09-17 23:15               ` Johannes Weiner
2021-09-20 10:03                 ` Kirill A. Shutemov
2021-09-17 21:13             ` Kent Overstreet
2021-09-17 22:25               ` Theodore Ts'o
2021-09-17 23:35                 ` Josef Bacik
2021-09-18  1:04             ` Dave Chinner
2021-09-18  4:51               ` Kent Overstreet
2021-09-20  1:04                 ` Dave Chinner
2021-09-16 21:58       ` David Howells
2021-09-20  2:17   ` Matthew Wilcox
2021-09-21 19:47     ` Johannes Weiner
2021-09-21 20:38       ` Matthew Wilcox
2021-09-21 21:11         ` Kent Overstreet
2021-09-21 21:22           ` Folios for 5.15 request - Was: re: Folio discussion recap - Kent Overstreet
2021-09-22 15:08             ` Johannes Weiner
2021-09-22 15:46               ` Kent Overstreet
2021-09-22 16:26                 ` Matthew Wilcox
2021-09-22 16:56                   ` Chris Mason
2021-09-22 19:54                     ` Matthew Wilcox
2021-09-22 20:15                       ` Kent Overstreet
2021-09-22 20:21                       ` Linus Torvalds
2021-09-22 20:21                         ` Linus Torvalds
2021-09-23  5:42               ` Kent Overstreet
2021-09-23 18:00                 ` Johannes Weiner
2021-09-23 19:31                   ` Matthew Wilcox
2021-09-23 20:20                   ` Kent Overstreet
2021-10-16  3:28               ` Matthew Wilcox
2021-10-18 16:47                 ` Johannes Weiner
2021-10-18 18:12                   ` Kent Overstreet
2021-10-18 20:45                     ` Johannes Weiner
2021-10-19 16:11                       ` Splitting struct page into multiple types " Kent Overstreet
2021-10-19 17:06                         ` Gao Xiang
2021-10-19 17:34                           ` Matthew Wilcox
2021-10-19 17:54                             ` Gao Xiang
2021-10-20 17:46                               ` Kent Overstreet
2021-10-19 17:37                         ` Jason Gunthorpe
2021-10-19 21:14                       ` David Howells
2021-10-18 18:28                   ` Folios for 5.15 request " Matthew Wilcox
2021-10-18 21:56                     ` Johannes Weiner
2021-10-18 23:16                       ` Kirill A. Shutemov
2021-10-19 15:16                         ` Johannes Weiner
2021-10-20  3:19                           ` Matthew Wilcox
2021-10-20  7:50                           ` David Hildenbrand
2021-10-20 17:26                             ` Matthew Wilcox
2021-10-20 18:04                               ` David Hildenbrand
2021-10-21  6:51                                 ` Christoph Hellwig
2021-10-21  7:21                                   ` David Hildenbrand
2021-10-21 12:03                                     ` Kent Overstreet
2021-10-21 12:35                                       ` David Hildenbrand
2021-10-21 12:38                                         ` Christoph Hellwig
2021-10-21 13:00                                           ` David Hildenbrand
2021-10-21 12:41                                         ` Matthew Wilcox
2021-10-20 17:39                           ` Kent Overstreet
2021-10-21 21:37                             ` Johannes Weiner
2021-10-22  1:52                               ` Matthew Wilcox
2021-10-22  7:59                                 ` David Hildenbrand
2021-10-22 13:01                                   ` Matthew Wilcox
2021-10-22 14:40                                     ` David Hildenbrand
2021-10-23  2:22                                       ` Matthew Wilcox
2021-10-23  5:02                                         ` Christoph Hellwig
2021-10-23  9:58                                         ` David Hildenbrand
2021-10-23 16:00                                           ` Kent Overstreet
2021-10-23 21:41                                             ` Matthew Wilcox
2021-10-23 22:23                                               ` Kent Overstreet
2021-10-25 15:35                                 ` Johannes Weiner
2021-10-25 15:52                                   ` Matthew Wilcox
2021-10-25 16:05                                   ` Kent Overstreet
2021-10-16 19:07               ` Matthew Wilcox
2021-10-18 17:25                 ` Johannes Weiner
2021-09-21 22:18           ` Folio discussion recap Matthew Wilcox
2021-09-23  0:45             ` Ira Weiny
2021-09-23  3:41               ` Matthew Wilcox
2021-09-23 22:12                 ` Ira Weiny
2021-09-29 15:24                   ` Matthew Wilcox
2021-09-21 21:59         ` Johannes Weiner

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