tree f8d7b2498ec83883d1434abd9042ae8e6863bdb2
parent aa877b3dc9f2a1fdffac4ea36bee97c21db11a69
author Nick Piggin <nickpiggin@yahoo.com.au> 1133214243 -0800
committer Linus Torvalds <torvalds@g5.osdl.org> 1133217744 -0800

[PATCH] mm: __alloc_pages cleanup fix

I believe this patch is required to fix breakage in the asynch reclaim
watermark logic introduced by this patch:

http://www.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=7fb1d9fca5c6e3b06773b69165a73f3fb786b8ee

Just some background of the watermark logic in case it isn't clear...
Basically what we have is this:

 ---  pages_high
   |
   | (a)
   |
 ---  pages_low
   |
   | (b)
   |
 ---  pages_min
   |
   | (c)
   |
 ---  0

Now when pages_low is reached, we want to kick asynch reclaim, which gives us
an interval of "b" before we must start synch reclaim, and gives kswapd an
interval of "a" before it need go back to sleep.

When pages_min is reached, normal allocators must enter synch reclaim, but
PF_MEMALLOC, ALLOC_HARDER, and ALLOC_HIGH (ie.  atomic allocations, recursive
allocations, etc.) get access to varying amounts of the reserve "c".

Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: "Seth, Rohit" <rohit.seth@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>