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From: William Kucharski <william.kucharski@oracle.com>
To: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>,
	"linux-fsdevel@vger.kernel.org" <linux-fsdevel@vger.kernel.org>,
	"linux-mm@kvack.org" <linux-mm@kvack.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v10 00/33] Memory folios
Date: Sat, 15 May 2021 10:26:29 +0000	[thread overview]
Message-ID: <26A8948B-00BC-49F1-A0B7-CE6310FA7A71@oracle.com> (raw)
In-Reply-To: <20210511214735.1836149-1-willy@infradead.org>

I have a nit on part 01/33, but will respond directly there.

For the series:

Reviewed-by: William Kucharski <william.kucharski@oracle.com>

> On May 11, 2021, at 3:47 PM, Matthew Wilcox (Oracle) <willy@infradead.org> wrote:
> 
> Managing memory in 4KiB pages is a serious overhead.  Many benchmarks
> benefit from a larger "page size".  As an example, an earlier iteration
> of this idea which used compound pages (and wasn't particularly tuned)
> got a 7% performance boost when compiling the kernel.
> 
> Using compound pages or THPs exposes a weakness of our type system.
> Functions are often unprepared for compound pages to be passed to them,
> and may only act on PAGE_SIZE chunks.  Even functions which are aware of
> compound pages may expect a head page, and do the wrong thing if passed
> a tail page.
> 
> We also waste a lot of instructions ensuring that we're not looking at
> a tail page.  Almost every call to PageFoo() contains one or more hidden
> calls to compound_head().  This also happens for get_page(), put_page()
> and many more functions.  There does not appear to be a way to tell gcc
> that it can cache the result of compound_head(), nor is there a way to
> tell it that compound_head() is idempotent.
> 
> This patch series uses a new type, the struct folio, to manage memory.
> It provides some basic infrastructure that's worthwhile in its own right,
> shrinking the kernel by about 5kB of text.
> 
> Since v9:
> - Rebase onto mmotm 2021-05-10-21-46
> - Add folio_memcg() definition for !MEMCG (intel lkp)
> - Change folio->private from an unsigned long to a void *
> - Use folio_page() to implement folio_file_page()
> - Add folio_try_get() and folio_try_get_rcu()
> - Trim back down to just the first few patches, which are better-reviewed.
> v9: https://lore.kernel.org/linux-mm/20210505150628.111735-1-willy@infradead.org/
> v8: https://lore.kernel.org/linux-mm/20210430180740.2707166-1-willy@infradead.org/
> 
> Matthew Wilcox (Oracle) (33):
>  mm: Introduce struct folio
>  mm: Add folio_pgdat and folio_zone
>  mm/vmstat: Add functions to account folio statistics
>  mm/debug: Add VM_BUG_ON_FOLIO and VM_WARN_ON_ONCE_FOLIO
>  mm: Add folio reference count functions
>  mm: Add folio_put
>  mm: Add folio_get
>  mm: Add folio_try_get_rcu
>  mm: Add folio flag manipulation functions
>  mm: Add folio_young and folio_idle
>  mm: Handle per-folio private data
>  mm/filemap: Add folio_index, folio_file_page and folio_contains
>  mm/filemap: Add folio_next_index
>  mm/filemap: Add folio_offset and folio_file_offset
>  mm/util: Add folio_mapping and folio_file_mapping
>  mm: Add folio_mapcount
>  mm/memcg: Add folio wrappers for various functions
>  mm/filemap: Add folio_unlock
>  mm/filemap: Add folio_lock
>  mm/filemap: Add folio_lock_killable
>  mm/filemap: Add __folio_lock_async
>  mm/filemap: Add __folio_lock_or_retry
>  mm/filemap: Add folio_wait_locked
>  mm/swap: Add folio_rotate_reclaimable
>  mm/filemap: Add folio_end_writeback
>  mm/writeback: Add folio_wait_writeback
>  mm/writeback: Add folio_wait_stable
>  mm/filemap: Add folio_wait_bit
>  mm/filemap: Add folio_wake_bit
>  mm/filemap: Convert page wait queues to be folios
>  mm/filemap: Add folio private_2 functions
>  fs/netfs: Add folio fscache functions
>  mm: Add folio_mapped
> 
> Documentation/core-api/mm-api.rst           |   4 +
> Documentation/filesystems/netfs_library.rst |   2 +
> fs/afs/write.c                              |   9 +-
> fs/cachefiles/rdwr.c                        |  16 +-
> fs/io_uring.c                               |   2 +-
> include/linux/memcontrol.h                  |  63 ++++
> include/linux/mm.h                          | 174 ++++++++--
> include/linux/mm_types.h                    |  71 ++++
> include/linux/mmdebug.h                     |  20 ++
> include/linux/netfs.h                       |  77 +++--
> include/linux/page-flags.h                  | 230 ++++++++++---
> include/linux/page_idle.h                   |  99 +++---
> include/linux/page_ref.h                    | 158 ++++++++-
> include/linux/pagemap.h                     | 358 ++++++++++++--------
> include/linux/swap.h                        |   7 +-
> include/linux/vmstat.h                      | 107 ++++++
> mm/Makefile                                 |   2 +-
> mm/filemap.c                                | 315 ++++++++---------
> mm/folio-compat.c                           |  43 +++
> mm/internal.h                               |   1 +
> mm/memory.c                                 |   8 +-
> mm/page-writeback.c                         |  72 ++--
> mm/page_io.c                                |   4 +-
> mm/swap.c                                   |  18 +-
> mm/swapfile.c                               |   8 +-
> mm/util.c                                   |  59 ++--
> 26 files changed, 1374 insertions(+), 553 deletions(-)
> create mode 100644 mm/folio-compat.c
> 
> -- 
> 2.30.2
> 
> 


  parent reply	other threads:[~2021-05-15 10:30 UTC|newest]

Thread overview: 96+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-05-11 21:47 Matthew Wilcox (Oracle)
2021-05-11 21:47 ` [PATCH v10 01/33] mm: Introduce struct folio Matthew Wilcox (Oracle)
2021-05-14 10:34   ` Vlastimil Babka
2021-05-14 10:40   ` Vlastimil Babka
2021-05-14 11:47     ` Matthew Wilcox
2021-05-15 10:55   ` William Kucharski
2021-05-15 20:14     ` Matthew Wilcox
2021-05-16 19:26       ` William Kucharski
2021-05-27  8:09   ` Christoph Hellwig
2021-05-11 21:47 ` [PATCH v10 02/33] mm: Add folio_pgdat and folio_zone Matthew Wilcox (Oracle)
2021-05-14 10:35   ` Vlastimil Babka
2021-05-11 21:47 ` [PATCH v10 03/33] mm/vmstat: Add functions to account folio statistics Matthew Wilcox (Oracle)
2021-05-14 10:36   ` Vlastimil Babka
2021-05-11 21:47 ` [PATCH v10 04/33] mm/debug: Add VM_BUG_ON_FOLIO and VM_WARN_ON_ONCE_FOLIO Matthew Wilcox (Oracle)
2021-05-14 10:44   ` Vlastimil Babka
2021-05-11 21:47 ` [PATCH v10 05/33] mm: Add folio reference count functions Matthew Wilcox (Oracle)
2021-05-14 11:04   ` Vlastimil Babka
2021-05-11 21:47 ` [PATCH v10 06/33] mm: Add folio_put Matthew Wilcox (Oracle)
2021-05-14 11:52   ` Vlastimil Babka
2021-05-11 21:47 ` [PATCH v10 07/33] mm: Add folio_get Matthew Wilcox (Oracle)
2021-05-14 11:56   ` Vlastimil Babka
2021-05-14 14:24     ` Matthew Wilcox
2021-05-14 15:39       ` Vlastimil Babka
2021-05-27  8:10       ` Christoph Hellwig
2021-05-27 22:53         ` Andrew Morton
2021-05-11 21:47 ` [PATCH v10 08/33] mm: Add folio_try_get_rcu Matthew Wilcox (Oracle)
2021-05-14 12:11   ` Vlastimil Babka
2021-05-27  8:16   ` Christoph Hellwig
2021-06-05  4:26     ` Matthew Wilcox
2021-06-06 14:13       ` Christoph Hellwig
2021-05-11 21:47 ` [PATCH v10 09/33] mm: Add folio flag manipulation functions Matthew Wilcox (Oracle)
2021-05-14 15:29   ` Vlastimil Babka
2021-05-11 21:47 ` [PATCH v10 10/33] mm: Add folio_young and folio_idle Matthew Wilcox (Oracle)
2021-05-14 15:33   ` Vlastimil Babka
2021-05-27  8:17   ` Christoph Hellwig
2021-05-11 21:47 ` [PATCH v10 11/33] mm: Handle per-folio private data Matthew Wilcox (Oracle)
2021-05-14 15:41   ` Vlastimil Babka
2021-05-11 21:47 ` [PATCH v10 12/33] mm/filemap: Add folio_index, folio_file_page and folio_contains Matthew Wilcox (Oracle)
2021-05-14 15:55   ` Vlastimil Babka
2021-05-15 15:51     ` Matthew Wilcox
2021-05-11 21:47 ` [PATCH v10 13/33] mm/filemap: Add folio_next_index Matthew Wilcox (Oracle)
2021-05-14 17:07   ` Vlastimil Babka
2021-05-11 21:47 ` [PATCH v10 14/33] mm/filemap: Add folio_offset and folio_file_offset Matthew Wilcox (Oracle)
2021-05-14 17:08   ` Vlastimil Babka
2021-05-11 21:47 ` [PATCH v10 15/33] mm/util: Add folio_mapping and folio_file_mapping Matthew Wilcox (Oracle)
2021-05-14 17:29   ` Vlastimil Babka
2021-05-11 21:47 ` [PATCH v10 16/33] mm: Add folio_mapcount Matthew Wilcox (Oracle)
2021-05-14 17:39   ` Vlastimil Babka
2021-05-18 18:45   ` Matthew Wilcox
2021-05-11 21:47 ` [PATCH v10 17/33] mm/memcg: Add folio wrappers for various functions Matthew Wilcox (Oracle)
2021-05-18  9:57   ` Vlastimil Babka
2021-05-11 21:47 ` [PATCH v10 18/33] mm/filemap: Add folio_unlock Matthew Wilcox (Oracle)
2021-05-18 10:06   ` Vlastimil Babka
2021-05-18 11:30     ` Matthew Wilcox
2021-05-11 21:47 ` [PATCH v10 19/33] mm/filemap: Add folio_lock Matthew Wilcox (Oracle)
2021-05-18 10:26   ` Vlastimil Babka
2021-05-11 21:47 ` [PATCH v10 20/33] mm/filemap: Add folio_lock_killable Matthew Wilcox (Oracle)
2021-05-18 10:31   ` Vlastimil Babka
2021-05-11 21:47 ` [PATCH v10 21/33] mm/filemap: Add __folio_lock_async Matthew Wilcox (Oracle)
2021-05-18 10:34   ` Vlastimil Babka
2021-05-11 21:47 ` [PATCH v10 22/33] mm/filemap: Add __folio_lock_or_retry Matthew Wilcox (Oracle)
2021-05-18 10:38   ` Vlastimil Babka
2021-05-18 10:45     ` Vlastimil Babka
2021-05-18 13:35     ` Matthew Wilcox
2021-05-11 21:47 ` [PATCH v10 23/33] mm/filemap: Add folio_wait_locked Matthew Wilcox (Oracle)
2021-05-18 10:41   ` Vlastimil Babka
2021-05-11 21:47 ` [PATCH v10 24/33] mm/swap: Add folio_rotate_reclaimable Matthew Wilcox (Oracle)
2021-05-18 10:48   ` Vlastimil Babka
2021-05-27  8:19   ` Christoph Hellwig
2021-05-11 21:47 ` [PATCH v10 25/33] mm/filemap: Add folio_end_writeback Matthew Wilcox (Oracle)
2021-05-18 11:08   ` Vlastimil Babka
2021-05-11 21:47 ` [PATCH v10 26/33] mm/writeback: Add folio_wait_writeback Matthew Wilcox (Oracle)
2021-05-18 11:12   ` Vlastimil Babka
2021-05-11 21:47 ` [PATCH v10 27/33] mm/writeback: Add folio_wait_stable Matthew Wilcox (Oracle)
2021-05-18 11:42   ` Vlastimil Babka
2021-05-18 13:55     ` Matthew Wilcox
2021-05-11 21:47 ` [PATCH v10 28/33] mm/filemap: Add folio_wait_bit Matthew Wilcox (Oracle)
2021-05-18 11:51   ` Vlastimil Babka
2021-05-11 21:47 ` [PATCH v10 29/33] mm/filemap: Add folio_wake_bit Matthew Wilcox (Oracle)
2021-05-18 11:53   ` Vlastimil Babka
2021-05-11 21:47 ` [PATCH v10 30/33] mm/filemap: Convert page wait queues to be folios Matthew Wilcox (Oracle)
2021-05-18 12:23   ` Vlastimil Babka
2021-05-11 21:47 ` [PATCH v10 31/33] mm/filemap: Add folio private_2 functions Matthew Wilcox (Oracle)
2021-05-18 12:26   ` Vlastimil Babka
2021-05-27  8:21   ` Christoph Hellwig
2021-05-11 21:47 ` [PATCH v10 32/33] fs/netfs: Add folio fscache functions Matthew Wilcox (Oracle)
2021-05-18 13:48   ` Vlastimil Babka
2021-05-27  8:23   ` Christoph Hellwig
2021-05-11 21:47 ` [PATCH v10 33/33] mm: Add folio_mapped Matthew Wilcox (Oracle)
2021-05-18 14:17   ` Vlastimil Babka
2021-05-27  8:31   ` Christoph Hellwig
2021-05-13 14:50 ` [PATCH v10 00/33] Memory folios Matthew Wilcox
2021-05-15 10:26 ` William Kucharski [this message]
2021-06-04  1:07 ` Matteo Croce
2021-06-04  2:13   ` Matthew Wilcox
2021-06-08 14:56     ` Matteo Croce

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