From 208d54e5513c0c02d85af0990901354c74364d5c Mon Sep 17 00:00:00 2001 From: Dave Hansen Date: Sat, 29 Oct 2005 18:16:52 -0700 Subject: [PATCH] memory hotplug locking: node_size_lock pgdat->node_size_lock is basically only neeeded in one place in the normal code: show_mem(), which is the arch-specific sysrq-m printing function. Strictly speaking, the architectures not doing memory hotplug do no need this locking in show_mem(). However, they are all included for completeness. This should also make any future consolidation of all of the implementations a little more straightforward. This lock is also held in the sparsemem code during a memory removal, as sections are invalidated. This is the place there pfn_valid() is made false for a memory area that's being removed. The lock is only required when doing pfn_valid() operations on memory which the user does not already have a reference on the page, such as in show_mem(). Signed-off-by: Dave Hansen Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/memory_hotplug.h | 34 ++++++++++++++++++++++++++++++++++ 1 file changed, 34 insertions(+) create mode 100644 include/linux/memory_hotplug.h (limited to 'include/linux/memory_hotplug.h') diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h new file mode 100644 index 000000000000..e8103be9d528 --- /dev/null +++ b/include/linux/memory_hotplug.h @@ -0,0 +1,34 @@ +#ifndef __LINUX_MEMORY_HOTPLUG_H +#define __LINUX_MEMORY_HOTPLUG_H + +#include +#include + +#ifdef CONFIG_MEMORY_HOTPLUG +/* + * pgdat resizing functions + */ +static inline +void pgdat_resize_lock(struct pglist_data *pgdat, unsigned long *flags) +{ + spin_lock_irqsave(&pgdat->node_size_lock, *flags); +} +static inline +void pgdat_resize_unlock(struct pglist_data *pgdat, unsigned long *flags) +{ + spin_lock_irqrestore(&pgdat->node_size_lock, *flags); +} +static inline +void pgdat_resize_init(struct pglist_data *pgdat) +{ + spin_lock_init(&pgdat->node_size_lock); +} +#else /* ! CONFIG_MEMORY_HOTPLUG */ +/* + * Stub functions for when hotplug is off + */ +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 +#endif /* __LINUX_MEMORY_HOTPLUG_H */ -- cgit v1.2.3 From bdc8cb984576ab5b550c8b24c6fa111a873503e3 Mon Sep 17 00:00:00 2001 From: Dave Hansen Date: Sat, 29 Oct 2005 18:16:53 -0700 Subject: [PATCH] memory hotplug locking: zone span seqlock See the "fixup bad_range()" patch for more information, but this actually creates a the lock to protect things making assumptions about a zone's size staying constant at runtime. Signed-off-by: Dave Hansen Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/memory_hotplug.h | 39 +++++++++++++++++++++++++++++++++++++-- 1 file changed, 37 insertions(+), 2 deletions(-) (limited to 'include/linux/memory_hotplug.h') 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 */ -- cgit v1.2.3 From 3947be1969a9ce455ec30f60ef51efb10e4323d1 Mon Sep 17 00:00:00 2001 From: Dave Hansen Date: Sat, 29 Oct 2005 18:16:54 -0700 Subject: [PATCH] memory hotplug: sysfs and add/remove functions This adds generic memory add/remove and supporting functions for memory hotplug into a new file as well as a memory hotplug kernel config option. Individual architecture patches will follow. For now, disable memory hotplug when swsusp is enabled. There's a lot of churn there right now. We'll fix it up properly once it calms down. Signed-off-by: Matt Tolentino Signed-off-by: Dave Hansen Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/memory_hotplug.h | 35 +++++++++++++++++++++++++++++++++++ 1 file changed, 35 insertions(+) (limited to 'include/linux/memory_hotplug.h') diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h index 4b08bc947578..01f03bc06eff 100644 --- a/include/linux/memory_hotplug.h +++ b/include/linux/memory_hotplug.h @@ -3,6 +3,8 @@ #include #include +#include +#include #ifdef CONFIG_MEMORY_HOTPLUG /* @@ -46,6 +48,19 @@ static inline void zone_seqlock_init(struct zone *zone) { seqlock_init(&zone->span_seqlock); } +extern int zone_grow_free_lists(struct zone *zone, unsigned long new_nr_pages); +extern int zone_grow_waitqueues(struct zone *zone, unsigned long nr_pages); +extern int add_one_highpage(struct page *page, int pfn, int bad_ppro); +/* need some defines for these for archs that don't support it */ +extern void online_page(struct page *page); +/* VM interface that may be used by firmware interface */ +extern int add_memory(u64 start, u64 size); +extern int remove_memory(u64 start, u64 size); +extern int online_pages(unsigned long, unsigned long); + +/* reasonably generic interface to expand the physical pages in a zone */ +extern int __add_pages(struct zone *zone, unsigned long start_pfn, + unsigned long nr_pages); #else /* ! CONFIG_MEMORY_HOTPLUG */ /* * Stub functions for when hotplug is off @@ -65,5 +80,25 @@ static inline int zone_span_seqretry(struct zone *zone, unsigned iv) 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) {} + +static inline int mhp_notimplemented(const char *func) +{ + printk(KERN_WARNING "%s() called, with CONFIG_MEMORY_HOTPLUG disabled\n", func); + dump_stack(); + return -ENOSYS; +} + +static inline int __add_pages(struct zone *zone, unsigned long start_pfn, + unsigned long nr_pages) +{ + return mhp_notimplemented(__FUNCTION__); +} #endif /* ! CONFIG_MEMORY_HOTPLUG */ +static inline int __remove_pages(struct zone *zone, unsigned long start_pfn, + unsigned long nr_pages) +{ + printk(KERN_WARNING "%s() called, not yet supported\n", __FUNCTION__); + dump_stack(); + return -ENOSYS; +} #endif /* __LINUX_MEMORY_HOTPLUG_H */ -- cgit v1.2.3