From: Nick Piggin <nickpiggin@yahoo.com.au>
Date: Wed, 4 Oct 2006 09:15:23 +0000 (-0700)
Subject: [PATCH] mm: micro optimise zone_watermark_ok
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=e80ee884ae0e3794ef2b65a18a767d502ad712ee;p=GitHub%2Fmoto-9609%2Fandroid_kernel_motorola_exynos9610.git

[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>
---

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 4f59d90b81e6..b5468de49869 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -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)