mm: compaction: add /sys trigger for per-node memory compaction

Add a per-node sysfs file called compact. When the file is written to, each zone in that node is compacted. The intention that this would be used by something like a job scheduler in a batch system before a job starts so that the job can allocate the maximum number of hugepages without significant start-up cost. Signed-off-by: Mel Gorman <mel@csn.ul.ie> Acked-by: Rik van Riel <riel@redhat.com> Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Reviewed-by: Christoph Lameter <cl@linux-foundation.org> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> Reviewed-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>

mm: compaction: add /sys trigger for per-node memory compaction
Add a per-node sysfs file called compact. When the file is written to, each zone in that node is compacted. The intention that this would be used by something like a job scheduler in a batch system before a job starts so that the job can allocate the maximum number of hugepages without significant start-up cost. Signed-off-by: Mel Gorman <mel@csn.ul.ie> Acked-by: Rik van Riel <riel@redhat.com> Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Reviewed-by: Christoph Lameter <cl@linux-foundation.org> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> Reviewed-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>
Mel Gorman · Linus Torvalds
1 parent 76ab0f530e
Showing 4 changed files with 49 additions and 0 deletions Side-by-side Diff
Documentation/ABI/testing/sysfs-devices-node
drivers/base/node.c
include/linux/compaction.h
mm/compaction.c
+What:		/sys/devices/system/node/nodeX/compact
+Date:		February 2010
+Contact:	Mel Gorman <mel@csn.ul.ie>
+Description:
+		When this file is written to, all memory within that node
+		will be compacted. When it completes, memory will be freed
+		into blocks which have as many contiguous pages as possible
@@ -9,6 +9,7 @@
 #include <linux/memory.h>
 #include <linux/node.h>
 #include <linux/hugetlb.h>
+#include <linux/compaction.h>
 #include <linux/cpumask.h>
 #include <linux/topology.h>
 #include <linux/nodemask.h>
@@ -246,6 +247,8 @@
 		scan_unevictable_register_node(node);
  
 		hugetlb_register_node(node);
+
+		compaction_register_node(node);
 	}
 	return error;
 }
@@ -12,5 +12,21 @@
 			void __user *buffer, size_t *length, loff_t *ppos);
 #endif /* CONFIG_COMPACTION */
  
+#if defined(CONFIG_COMPACTION) && defined(CONFIG_SYSFS) && defined(CONFIG_NUMA)
+extern int compaction_register_node(struct node *node);
+extern void compaction_unregister_node(struct node *node);
+
+#else
+
+static inline int compaction_register_node(struct node *node)
+{
+	return 0;
+}
+
+static inline void compaction_unregister_node(struct node *node)
+{
+}
+#endif /* CONFIG_COMPACTION && CONFIG_SYSFS && CONFIG_NUMA */
+
 #endif /* _LINUX_COMPACTION_H */
@@ -13,6 +13,7 @@
 #include <linux/mm_inline.h>
 #include <linux/backing-dev.h>
 #include <linux/sysctl.h>
+#include <linux/sysfs.h>
 #include "internal.h"
  
 /*
@@ -453,4 +454,26 @@
  
 	return 0;
 }
+
+#if defined(CONFIG_SYSFS) && defined(CONFIG_NUMA)
+ssize_t sysfs_compact_node(struct sys_device *dev,
+			struct sysdev_attribute *attr,
+			const char *buf, size_t count)
+{
+	compact_node(dev->id);
+
+	return count;
+}
+static SYSDEV_ATTR(compact, S_IWUSR, NULL, sysfs_compact_node);
+
+int compaction_register_node(struct node *node)
+{
+	return sysdev_create_file(&node->sysdev, &attr_compact);
+}
+
+void compaction_unregister_node(struct node *node)
+{
+	return sysdev_remove_file(&node->sysdev, &attr_compact);
+}
+#endif /* CONFIG_SYSFS && CONFIG_NUMA */
	1	+What: /sys/devices/system/node/nodeX/compact
	2	+Date: February 2010
	3	+Contact: Mel Gorman <mel@csn.ul.ie>
	4	+Description:
	5	+ When this file is written to, all memory within that node
	6	+ will be compacted. When it completes, memory will be freed
	7	+ into blocks which have as many contiguous pages as possible
...	...	@@ -9,6 +9,7 @@
9	9	#include <linux/memory.h>
10	10	#include <linux/node.h>
11	11	#include <linux/hugetlb.h>
	12	+#include <linux/compaction.h>
12	13	#include <linux/cpumask.h>
13	14	#include <linux/topology.h>
14	15	#include <linux/nodemask.h>
...	...	@@ -246,6 +247,8 @@
246	247	scan_unevictable_register_node(node);
247	248
248	249	hugetlb_register_node(node);
	250	+
	251	+ compaction_register_node(node);
249	252	}
250	253	return error;
251	254	}
...	...	@@ -12,5 +12,21 @@
12	12	void __user buffer, size_t length, loff_t *ppos);
13	13	#endif /* CONFIG_COMPACTION */
14	14
	15	+#if defined(CONFIG_COMPACTION) && defined(CONFIG_SYSFS) && defined(CONFIG_NUMA)
	16	+extern int compaction_register_node(struct node *node);
	17	+extern void compaction_unregister_node(struct node *node);
	18	+
	19	+#else
	20	+
	21	+static inline int compaction_register_node(struct node *node)
	22	+{
	23	+ return 0;
	24	+}
	25	+
	26	+static inline void compaction_unregister_node(struct node *node)
	27	+{
	28	+}
	29	+#endif /* CONFIG_COMPACTION && CONFIG_SYSFS && CONFIG_NUMA */
	30	+
15	31	#endif /* _LINUX_COMPACTION_H */
...	...	@@ -13,6 +13,7 @@
13	13	#include <linux/mm_inline.h>
14	14	#include <linux/backing-dev.h>
15	15	#include <linux/sysctl.h>
	16	+#include <linux/sysfs.h>
16	17	#include "internal.h"
17	18
18	19	/*
...	...	@@ -453,4 +454,26 @@
453	454
454	455	return 0;
455	456	}
	457	+
	458	+#if defined(CONFIG_SYSFS) && defined(CONFIG_NUMA)
	459	+ssize_t sysfs_compact_node(struct sys_device *dev,
	460	+ struct sysdev_attribute *attr,
	461	+ const char *buf, size_t count)
	462	+{
	463	+ compact_node(dev->id);
	464	+
	465	+ return count;
	466	+}
	467	+static SYSDEV_ATTR(compact, S_IWUSR, NULL, sysfs_compact_node);
	468	+
	469	+int compaction_register_node(struct node *node)
	470	+{
	471	+ return sysdev_create_file(&node->sysdev, &attr_compact);
	472	+}
	473	+
	474	+void compaction_unregister_node(struct node *node)
	475	+{
	476	+ return sysdev_remove_file(&node->sysdev, &attr_compact);
	477	+}
	478	+#endif /* CONFIG_SYSFS && CONFIG_NUMA */