Commit e80ee884 authored Oct 04, 2006 by Nick Piggin Committed by Linus Torvalds Oct 04, 2006

[PATCH] mm: micro optimise zone_watermark_ok



Having min be a signed quantity means gcc can't turn high latency divides
into shifts.  There happen to be two such divides for GFP_ATOMIC (ie.
networking, ie.  important) allocations, one of which depends on the other.
 Fixing this makes code smaller as a bonus.

Shame on somebody (probably me).

Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

parent b2abacf3

mm/page_alloc.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -900,7 +900,8 @@ int zone_watermark_ok(struct zone *z, int order, unsigned long mark,
		int classzone_idx, int alloc_flags)
		{
		/* free_pages my go negative - that's OK */
		long min = mark, free_pages = z->free_pages - (1 << order) + 1;
		unsigned long min = mark;
		long free_pages = z->free_pages - (1 << order) + 1;
		int o;

		if (alloc_flags & ALLOC_HIGH)