lkml.org 
[lkml]   [2018]   [Mar]   [2]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH v4 2/4] mm: Split page_type out from _map_count
On Thu, Mar 01, 2018 at 01:15:21PM -0800, Matthew Wilcox wrote:
> From: Matthew Wilcox <mawilcox@microsoft.com>
>
> We're already using a union of many fields here, so stop abusing the
> _map_count and make page_type its own field. That implies renaming some

s/_map_count/_mapcount/

and in subject.

> of the machinery that creates PageBuddy, PageBalloon and PageKmemcg;
> bring back the PG_buddy, PG_balloon and PG_kmemcg names.
>
> As suggested by Kirill, make page_type a bitmask. Because it starts out
> life as -1 (thanks to sharing the storage with _map_count), setting a
> page flag means clearing the appropriate bit. This gives us space for
> probably twenty or so extra bits (depending how paranoid we want to be
> about _mapcount underflow).
>
> Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>

Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>

--
Kirill A. Shutemov

\
 
 \ /
  Last update: 2018-03-02 09:18    [W:0.056 / U:0.192 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site