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authorDave Hansen <haveblue@us.ibm.com>2005-10-29 18:16:53 -0700
committerLinus Torvalds <torvalds@g5.osdl.org>2005-10-29 21:40:44 -0700
commitbdc8cb984576ab5b550c8b24c6fa111a873503e3 (patch)
treef94548988874caa10d770e6e65bc50c925abf825 /mm
parent208d54e5513c0c02d85af0990901354c74364d5c (diff)
[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 <haveblue@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'mm')
-rw-r--r--mm/page_alloc.c19
1 files changed, 14 insertions, 5 deletions
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 32fad6d2320..817635f2ab6 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -33,6 +33,7 @@
#include <linux/sysctl.h>
#include <linux/cpu.h>
#include <linux/cpuset.h>
+#include <linux/memory_hotplug.h>
#include <linux/nodemask.h>
#include <linux/vmalloc.h>
@@ -80,12 +81,19 @@ unsigned long __initdata nr_all_pages;
static int page_outside_zone_boundaries(struct zone *zone, struct page *page)
{
- if (page_to_pfn(page) >= zone->zone_start_pfn + zone->spanned_pages)
- return 1;
- if (page_to_pfn(page) < zone->zone_start_pfn)
- return 1;
+ int ret = 0;
+ unsigned seq;
+ unsigned long pfn = page_to_pfn(page);
- return 0;
+ do {
+ seq = zone_span_seqbegin(zone);
+ if (pfn >= zone->zone_start_pfn + zone->spanned_pages)
+ ret = 1;
+ else if (pfn < zone->zone_start_pfn)
+ ret = 1;
+ } while (zone_span_seqretry(zone, seq));
+
+ return ret;
}
static int page_is_consistent(struct zone *zone, struct page *page)
@@ -1980,6 +1988,7 @@ static void __init free_area_init_core(struct pglist_data *pgdat,
zone->name = zone_names[j];
spin_lock_init(&zone->lock);
spin_lock_init(&zone->lru_lock);
+ zone_seqlock_init(zone);
zone->zone_pgdat = pgdat;
zone->free_pages = 0;