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 <haveblue@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
35 lines
945 B
C
35 lines
945 B
C
#ifndef __LINUX_MEMORY_HOTPLUG_H
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#define __LINUX_MEMORY_HOTPLUG_H
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#include <linux/mmzone.h>
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#include <linux/spinlock.h>
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#ifdef CONFIG_MEMORY_HOTPLUG
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/*
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* pgdat resizing functions
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*/
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static inline
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void pgdat_resize_lock(struct pglist_data *pgdat, unsigned long *flags)
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{
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spin_lock_irqsave(&pgdat->node_size_lock, *flags);
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}
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static inline
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void pgdat_resize_unlock(struct pglist_data *pgdat, unsigned long *flags)
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{
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spin_lock_irqrestore(&pgdat->node_size_lock, *flags);
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}
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static inline
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void pgdat_resize_init(struct pglist_data *pgdat)
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{
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spin_lock_init(&pgdat->node_size_lock);
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}
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#else /* ! CONFIG_MEMORY_HOTPLUG */
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/*
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* Stub functions for when hotplug is off
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*/
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static inline void pgdat_resize_lock(struct pglist_data *p, unsigned long *f) {}
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static inline void pgdat_resize_unlock(struct pglist_data *p, unsigned long *f) {}
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static inline void pgdat_resize_init(struct pglist_data *pgdat) {}
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#endif
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#endif /* __LINUX_MEMORY_HOTPLUG_H */
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