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authorDave Hansen <haveblue@us.ibm.com>2005-10-29 21:16:52 -0400
committerLinus Torvalds <torvalds@g5.osdl.org>2005-10-30 00:40:44 -0400
commit208d54e5513c0c02d85af0990901354c74364d5c (patch)
tree83922f1d4a83f19bffcbff299044f421bd7e9c73 /include/linux/mmzone.h
parentc6a57e19e464db118dc4ab9cfe9e9748c6d630a0 (diff)
[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 <haveblue@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'include/linux/mmzone.h')
-rw-r--r--include/linux/mmzone.h12
1 files changed, 12 insertions, 0 deletions
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index 4674145bb63d..e050d68963a1 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -273,6 +273,16 @@ typedef struct pglist_data {
273 struct page *node_mem_map; 273 struct page *node_mem_map;
274#endif 274#endif
275 struct bootmem_data *bdata; 275 struct bootmem_data *bdata;
276#ifdef CONFIG_MEMORY_HOTPLUG
277 /*
278 * Must be held any time you expect node_start_pfn, node_present_pages
279 * or node_spanned_pages stay constant. Holding this will also
280 * guarantee that any pfn_valid() stays that way.
281 *
282 * Nests above zone->lock and zone->size_seqlock.
283 */
284 spinlock_t node_size_lock;
285#endif
276 unsigned long node_start_pfn; 286 unsigned long node_start_pfn;
277 unsigned long node_present_pages; /* total number of physical pages */ 287 unsigned long node_present_pages; /* total number of physical pages */
278 unsigned long node_spanned_pages; /* total size of physical page 288 unsigned long node_spanned_pages; /* total size of physical page
@@ -293,6 +303,8 @@ typedef struct pglist_data {
293#endif 303#endif
294#define nid_page_nr(nid, pagenr) pgdat_page_nr(NODE_DATA(nid),(pagenr)) 304#define nid_page_nr(nid, pagenr) pgdat_page_nr(NODE_DATA(nid),(pagenr))
295 305
306#include <linux/memory_hotplug.h>
307
296extern struct pglist_data *pgdat_list; 308extern struct pglist_data *pgdat_list;
297 309
298void __get_zone_counts(unsigned long *active, unsigned long *inactive, 310void __get_zone_counts(unsigned long *active, unsigned long *inactive,