diff options
Diffstat (limited to 'include/linux/mmzone.h')
-rw-r--r-- | include/linux/mmzone.h | 25 |
1 files changed, 19 insertions, 6 deletions
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index 34cbefd2ebde..ebfc238cc243 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 @@ -149,15 +160,17 @@ struct zone { unsigned long pages_scanned; /* since last reclaim */ int all_unreclaimable; /* All pages pinned */ - /* - * Does the allocator try to reclaim pages from the zone as soon - * as it fails a watermark_ok() in __alloc_pages? - */ - int reclaim_pages; /* A count of how many reclaimers are scanning this zone */ atomic_t reclaim_in_progress; /* + * timestamp (in jiffies) of the last zone reclaim that did not + * result in freeing of pages. This is used to avoid repeated scans + * if all memory in the zone is in use. + */ + unsigned long last_unsuccessful_zone_reclaim; + + /* * prev_priority holds the scanning priority for this zone. It is * defined as the scanning priority at which we achieved our reclaim * target at the previous try_to_free_pages() or balance_pgdat() |