Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1361613

Re: [PATCH 43/71] jbd2: get rid of PAGE_CACHE_* and page_cache_{get,release} macros

Show all headers | View raw

On Sun 20-03-16 21:40:50, Kirill A. Shutemov wrote:
> PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time ago
> with promise that one day it will be possible to implement page cache with
> bigger chunks than PAGE_SIZE.
> 
> This promise never materialized. And unlikely will.
> 
> We have many places where PAGE_CACHE_SIZE assumed to be equal to
> PAGE_SIZE. And it's constant source of confusion on whether PAGE_CACHE_*
> or PAGE_* constant should be used in a particular case, especially on the
> border between fs and mm.
> 
> Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much
> breakage to be doable.
> 
> Let's stop pretending that pages in page cache are special. They are not.
> 
> The changes are pretty straight-forward:
> 
>  - <foo> << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;
> 
>  - PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN};
> 
>  - page_cache_get() -> get_page();
> 
>  - page_cache_release() -> put_page();
> 
> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
> Cc: "Theodore Ts'o" <tytso@mit.edu>
> Cc: Jan Kara <jack@suse.com>

Reviewed-by: Jan Kara <jack@suse.cz>

								Honza
-- 
Jan Kara <jack@suse.com>
SUSE Labs, CR

Back to linux.kernel | Previous | Next — Previous in thread | Find similar | Unroll thread

Thread

[PATCH 43/71] jbd2: get rid of PAGE_CACHE_* and page_cache_{get,release} macros "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> - 2016-03-20 19:50 +0100
  Re: [PATCH 43/71] jbd2: get rid of PAGE_CACHE_* and  page_cache_{get,release} macros Jan Kara <jack@suse.cz> - 2016-03-21 09:50 +0100

csiph-web