diff options
author | Dave Kleikamp <shaggy@austin.ibm.com> | 2006-03-14 17:05:45 -0600 |
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committer | Dave Kleikamp <shaggy@austin.ibm.com> | 2006-03-14 17:05:45 -0600 |
commit | c5111f504d2a9b0d258d7c4752b4093523315989 (patch) | |
tree | 6a52864aff79691689aea21cb0cb928327d5de5b /include/linux/mmzone.h | |
parent | 69eb66d7da7dba2696281981347698e1693c2340 (diff) | |
parent | a488edc914aa1d766a4e2c982b5ae03d5657ec1b (diff) |
Merge with /home/shaggy/git/linus-clean/
Diffstat (limited to 'include/linux/mmzone.h')
-rw-r--r-- | include/linux/mmzone.h | 13 |
1 files changed, 12 insertions, 1 deletions
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index 93a849f742d..ebfc238cc24 100644 --- a/include/linux/mmzone.h +++ b/include/linux/mmzone.h @@ -91,10 +91,21 @@ struct per_cpu_pageset { * be 8 (2 ** 3) zonelists. GFP_ZONETYPES defines the number of possible * combinations of zone modifiers in "zone modifier space". * + * As an optimisation any zone modifier bits which are only valid when + * no other zone modifier bits are set (loners) should be placed in + * the highest order bits of this field. This allows us to reduce the + * extent of the zonelists thus saving space. For example in the case + * of three zone modifier bits, we could require up to eight zonelists. + * If the left most zone modifier is a "loner" then the highest valid + * zonelist would be four allowing us to allocate only five zonelists. + * Use the first form for GFP_ZONETYPES when the left most bit is not + * a "loner", otherwise use the second. + * * NOTE! Make sure this matches the zones in <linux/gfp.h> */ #define GFP_ZONEMASK 0x07 -#define GFP_ZONETYPES 5 +/* #define GFP_ZONETYPES (GFP_ZONEMASK + 1) */ /* Non-loner */ +#define GFP_ZONETYPES ((GFP_ZONEMASK + 1) / 2 + 1) /* Loner */ /* * On machines where it is needed (eg PCs) we divide physical memory |