diff options
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/memory_hotplug.h | 39 | ||||
| -rw-r--r-- | include/linux/mmzone.h | 15 |
2 files changed, 52 insertions, 2 deletions
diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h index e8103be9d528..4b08bc947578 100644 --- a/include/linux/memory_hotplug.h +++ b/include/linux/memory_hotplug.h @@ -16,13 +16,36 @@ void pgdat_resize_lock(struct pglist_data *pgdat, unsigned long *flags) static inline void pgdat_resize_unlock(struct pglist_data *pgdat, unsigned long *flags) { - spin_lock_irqrestore(&pgdat->node_size_lock, *flags); + spin_unlock_irqrestore(&pgdat->node_size_lock, *flags); } static inline void pgdat_resize_init(struct pglist_data *pgdat) { spin_lock_init(&pgdat->node_size_lock); } +/* + * Zone resizing functions + */ +static inline unsigned zone_span_seqbegin(struct zone *zone) +{ + return read_seqbegin(&zone->span_seqlock); +} +static inline int zone_span_seqretry(struct zone *zone, unsigned iv) +{ + return read_seqretry(&zone->span_seqlock, iv); +} +static inline void zone_span_writelock(struct zone *zone) +{ + write_seqlock(&zone->span_seqlock); +} +static inline void zone_span_writeunlock(struct zone *zone) +{ + write_sequnlock(&zone->span_seqlock); +} +static inline void zone_seqlock_init(struct zone *zone) +{ + seqlock_init(&zone->span_seqlock); +} #else /* ! CONFIG_MEMORY_HOTPLUG */ /* * Stub functions for when hotplug is off @@ -30,5 +53,17 @@ void pgdat_resize_init(struct pglist_data *pgdat) static inline void pgdat_resize_lock(struct pglist_data *p, unsigned long *f) {} static inline void pgdat_resize_unlock(struct pglist_data *p, unsigned long *f) {} static inline void pgdat_resize_init(struct pglist_data *pgdat) {} -#endif + +static inline unsigned zone_span_seqbegin(struct zone *zone) +{ + return 0; +} +static inline int zone_span_seqretry(struct zone *zone, unsigned iv) +{ + return 0; +} +static inline void zone_span_writelock(struct zone *zone) {} +static inline void zone_span_writeunlock(struct zone *zone) {} +static inline void zone_seqlock_init(struct zone *zone) {} +#endif /* ! CONFIG_MEMORY_HOTPLUG */ #endif /* __LINUX_MEMORY_HOTPLUG_H */ diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index e050d68963a1..f5fa3082fd6a 100644 --- a/include/linux/mmzone.h +++ b/include/linux/mmzone.h @@ -12,6 +12,7 @@ #include <linux/threads.h> #include <linux/numa.h> #include <linux/init.h> +#include <linux/seqlock.h> #include <asm/atomic.h> /* Free memory management - zoned buddy allocator. */ @@ -137,6 +138,10 @@ struct zone { * free areas of different sizes */ spinlock_t lock; +#ifdef CONFIG_MEMORY_HOTPLUG + /* see spanned/present_pages for more description */ + seqlock_t span_seqlock; +#endif struct free_area free_area[MAX_ORDER]; @@ -220,6 +225,16 @@ struct zone { /* zone_start_pfn == zone_start_paddr >> PAGE_SHIFT */ unsigned long zone_start_pfn; + /* + * zone_start_pfn, spanned_pages and present_pages are all + * protected by span_seqlock. It is a seqlock because it has + * to be read outside of zone->lock, and it is done in the main + * allocator path. But, it is written quite infrequently. + * + * The lock is declared along with zone->lock because it is + * frequently read in proximity to zone->lock. It's good to + * give them a chance of being in the same cacheline. + */ unsigned long spanned_pages; /* total size, including holes */ unsigned long present_pages; /* amount of memory (excluding holes) */ |
