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authorKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>2007-10-16 01:26:11 -0700
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-10-16 09:43:02 -0700
commita5d76b54a3f3a40385d7f76069a2feac9f1bad63 (patch)
treef58c432a4224b3be032bd4a4afa79dfa55d198a6 /include
parent75884fb1c6388f3713ddcca662f3647b3129aaeb (diff)
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memory unplug: page isolation
Implement generic chunk-of-pages isolation method by using page grouping ops. This patch add MIGRATE_ISOLATE to MIGRATE_TYPES. By this - MIGRATE_TYPES increases. - bitmap for migratetype is enlarged. pages of MIGRATE_ISOLATE migratetype will not be allocated even if it is free. By this, you can isolated *freed* pages from users. How-to-free pages is not a purpose of this patch. You may use reclaim and migrate codes to free pages. If start_isolate_page_range(start,end) is called, - migratetype of the range turns to be MIGRATE_ISOLATE if its type is MIGRATE_MOVABLE. (*) this check can be updated if other memory reclaiming works make progress. - MIGRATE_ISOLATE is not on migratetype fallback list. - All free pages and will-be-freed pages are isolated. To check all pages in the range are isolated or not, use test_pages_isolated(), To cancel isolation, use undo_isolate_page_range(). Changes V6 -> V7 - removed unnecessary #ifdef There are HOLES_IN_ZONE handling codes...I'm glad if we can remove them.. Signed-off-by: Yasunori Goto <y-goto@jp.fujitsu.com> Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include')
-rw-r--r--include/linux/mmzone.h3
-rw-r--r--include/linux/page-isolation.h37
-rw-r--r--include/linux/pageblock-flags.h2
3 files changed, 40 insertions, 2 deletions
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index 20ea42c45e4a..f4bfe824834f 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -37,7 +37,8 @@
#define MIGRATE_RECLAIMABLE 1
#define MIGRATE_MOVABLE 2
#define MIGRATE_RESERVE 3
-#define MIGRATE_TYPES 4
+#define MIGRATE_ISOLATE 4 /* can't allocate from here */
+#define MIGRATE_TYPES 5
#define for_each_migratetype_order(order, type) \
for (order = 0; order < MAX_ORDER; order++) \
diff --git a/include/linux/page-isolation.h b/include/linux/page-isolation.h
new file mode 100644
index 000000000000..051c1b1ede4e
--- /dev/null
+++ b/include/linux/page-isolation.h
@@ -0,0 +1,37 @@
+#ifndef __LINUX_PAGEISOLATION_H
+#define __LINUX_PAGEISOLATION_H
+
+/*
+ * Changes migrate type in [start_pfn, end_pfn) to be MIGRATE_ISOLATE.
+ * If specified range includes migrate types other than MOVABLE,
+ * this will fail with -EBUSY.
+ *
+ * For isolating all pages in the range finally, the caller have to
+ * free all pages in the range. test_page_isolated() can be used for
+ * test it.
+ */
+extern int
+start_isolate_page_range(unsigned long start_pfn, unsigned long end_pfn);
+
+/*
+ * Changes MIGRATE_ISOLATE to MIGRATE_MOVABLE.
+ * target range is [start_pfn, end_pfn)
+ */
+extern int
+undo_isolate_page_range(unsigned long start_pfn, unsigned long end_pfn);
+
+/*
+ * test all pages in [start_pfn, end_pfn)are isolated or not.
+ */
+extern int
+test_pages_isolated(unsigned long start_pfn, unsigned long end_pfn);
+
+/*
+ * Internal funcs.Changes pageblock's migrate type.
+ * Please use make_pagetype_isolated()/make_pagetype_movable().
+ */
+extern int set_migratetype_isolate(struct page *page);
+extern void unset_migratetype_isolate(struct page *page);
+
+
+#endif
diff --git a/include/linux/pageblock-flags.h b/include/linux/pageblock-flags.h
index 9ea130829fb4..e875905f7b12 100644
--- a/include/linux/pageblock-flags.h
+++ b/include/linux/pageblock-flags.h
@@ -31,7 +31,7 @@
/* Bit indices that affect a whole block of pages */
enum pageblock_bits {
- PB_range(PB_migrate, 2), /* 2 bits required for migrate types */
+ PB_range(PB_migrate, 3), /* 3 bits required for migrate types */
NR_PAGEBLOCK_BITS
};