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authorDavid Rientjes <rientjes@google.com>2009-12-14 17:58:33 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2009-12-15 08:53:13 -0800
commit8fe23e057172223fe2048768a4d87ab7de7477bc (patch)
treed176d8e588fca088adfcb110e7c1bc53a839dc84
parent9b5e5d0fdc91b73bba8cf5e0fbe3521a953e4e4d (diff)
mm: clear node in N_HIGH_MEMORY and stop kswapd when all memory is offlined
When memory is hot-removed, its node must be cleared in N_HIGH_MEMORY if there are no present pages left. In such a situation, kswapd must also be stopped since it has nothing left to do. Signed-off-by: David Rientjes <rientjes@google.com> Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: Yasunori Goto <y-goto@jp.fujitsu.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Rafael J. Wysocki <rjw@sisk.pl> Cc: Rik van Riel <riel@redhat.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Randy Dunlap <randy.dunlap@oracle.com> Cc: Nishanth Aravamudan <nacc@us.ibm.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: David Rientjes <rientjes@google.com> Cc: Adam Litke <agl@us.ibm.com> Cc: Andy Whitcroft <apw@canonical.com> Cc: Eric Whitney <eric.whitney@hp.com> Cc: Christoph Lameter <cl@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--include/linux/swap.h1
-rw-r--r--mm/memory_hotplug.c4
-rw-r--r--mm/vmscan.c28
3 files changed, 27 insertions, 6 deletions
diff --git a/include/linux/swap.h b/include/linux/swap.h
index 4ec90019c1a..abce8a0b250 100644
--- a/include/linux/swap.h
+++ b/include/linux/swap.h
@@ -273,6 +273,7 @@ extern int scan_unevictable_register_node(struct node *node);
extern void scan_unevictable_unregister_node(struct node *node);
extern int kswapd_run(int nid);
+extern void kswapd_stop(int nid);
#ifdef CONFIG_MMU
/* linux/mm/shmem.c */
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index e8116f8bdff..bc5a08138f1 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -853,6 +853,10 @@ repeat:
setup_per_zone_wmarks();
calculate_zone_inactive_ratio(zone);
+ if (!node_present_pages(node)) {
+ node_clear_state(node, N_HIGH_MEMORY);
+ kswapd_stop(node);
+ }
vm_total_pages = nr_free_pagecache_pages();
writeback_set_ratelimit();
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 777af57fd8c..d0a631a428a 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -2173,6 +2173,7 @@ static int kswapd(void *p)
order = 0;
for ( ; ; ) {
unsigned long new_order;
+ int ret;
prepare_to_wait(&pgdat->kswapd_wait, &wait, TASK_INTERRUPTIBLE);
new_order = pgdat->kswapd_max_order;
@@ -2184,19 +2185,23 @@ static int kswapd(void *p)
*/
order = new_order;
} else {
- if (!freezing(current))
+ if (!freezing(current) && !kthread_should_stop())
schedule();
order = pgdat->kswapd_max_order;
}
finish_wait(&pgdat->kswapd_wait, &wait);
- if (!try_to_freeze()) {
- /* We can speed up thawing tasks if we don't call
- * balance_pgdat after returning from the refrigerator
- */
+ ret = try_to_freeze();
+ if (kthread_should_stop())
+ break;
+
+ /*
+ * We can speed up thawing tasks if we don't call balance_pgdat
+ * after returning from the refrigerator
+ */
+ if (!ret)
balance_pgdat(pgdat, order);
- }
}
return 0;
}
@@ -2451,6 +2456,17 @@ int kswapd_run(int nid)
return ret;
}
+/*
+ * Called by memory hotplug when all memory in a node is offlined.
+ */
+void kswapd_stop(int nid)
+{
+ struct task_struct *kswapd = NODE_DATA(nid)->kswapd;
+
+ if (kswapd)
+ kthread_stop(kswapd);
+}
+
static int __init kswapd_init(void)
{
int nid;