The patch titled
mm: clear node in N_HIGH_MEMORY and stop kswapd when all memory is offlined
has been added to the -mm tree. Its filename is
mm-clear-node-in-n_high_memory-and-stop-kswapd-when-all-memory-is-offlined.patch
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------------------------------------------------------
Subject: mm: clear node in N_HIGH_MEMORY and stop kswapd when all memory is offlined
From: David Rientjes <rientjes@xxxxxxxxxx>
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@xxxxxxxxxx>
Signed-off-by: Lee Schermerhorn <lee.schermerhorn@xxxxxx>
Cc: Christoph Lameter <cl@xxxxxxxxxxxxxxxxxxxx>
Cc: Yasunori Goto <y-goto@xxxxxxxxxxxxxx>
Cc: Mel Gorman <mel@xxxxxxxxx>
Cc: Rafael J. Wysocki <rjw@xxxxxxx>
Cc: Rik van Riel <riel@xxxxxxxxxx>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>
Cc: Lee Schermerhorn <lee.schermerhorn@xxxxxx>
Cc: Mel Gorman <mel@xxxxxxxxx>
Cc: Randy Dunlap <randy.dunlap@xxxxxxxxxx>
Cc: Nishanth Aravamudan <nacc@xxxxxxxxxx>
Cc: Andi Kleen <andi@xxxxxxxxxxxxxx>
Cc: David Rientjes <rientjes@xxxxxxxxxx>
Cc: Adam Litke <agl@xxxxxxxxxx>
Cc: Andy Whitcroft <apw@xxxxxxxxxxxxx>
Cc: Eric Whitney <eric.whitney@xxxxxx>
Cc: Christoph Lameter <cl@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
diff -puN include/linux/swap.h~mm-clear-node-in-n_high_memory-and-stop-kswapd-when-all-memory-is-offlined include/linux/swap.h
--- a/include/linux/swap.h~mm-clear-node-in-n_high_memory-and-stop-kswapd-when-all-memory-is-offlined
+++ a/include/linux/swap.h
@@ -273,6 +273,7 @@ extern int scan_unevictable_register_nod
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 -puN mm/memory_hotplug.c~mm-clear-node-in-n_high_memory-and-stop-kswapd-when-all-memory-is-offlined mm/memory_hotplug.c
--- a/mm/memory_hotplug.c~mm-clear-node-in-n_high_memory-and-stop-kswapd-when-all-memory-is-offlined
+++ a/mm/memory_hotplug.c
@@ -842,6 +842,10 @@ 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 -puN mm/vmscan.c~mm-clear-node-in-n_high_memory-and-stop-kswapd-when-all-memory-is-offlined mm/vmscan.c
--- a/mm/vmscan.c~mm-clear-node-in-n_high_memory-and-stop-kswapd-when-all-memory-is-offlined
+++ a/mm/vmscan.c
@@ -2167,6 +2167,7 @@ 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;
@@ -2178,19 +2179,23 @@ 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;
}
@@ -2445,6 +2450,17 @@ 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;
_
Patches currently in -mm which might be from rientjes@xxxxxxxxxx are
linux-next.patch
revert-mm-oom-analysis-add-buffer-cache-information-to-show_free_areas.patch
oom-dump-stack-and-vm-state-when-oom-killer-panics.patch
nodemask-make-nodemask_alloc-more-general.patch
hugetlb-rework-hstate_next_node_-functions.patch
hugetlb-add-nodemask-arg-to-huge-page-alloc-free-and-surplus-adjust-functions.patch
hugetlb-add-nodemask-arg-to-huge-page-alloc-free-and-surplus-adjust-functions-fix.patch
hugetlb-factor-init_nodemask_of_node.patch
hugetlb-derive-huge-pages-nodes-allowed-from-task-mempolicy.patch
hugetlb-add-generic-definition-of-numa_no_node.patch
hugetlb-add-per-node-hstate-attributes.patch
hugetlb-update-hugetlb-documentation-for-numa-controls.patch
hugetlb-use-only-nodes-with-memory-for-huge-pages.patch
mm-clear-node-in-n_high_memory-and-stop-kswapd-when-all-memory-is-offlined.patch
hugetlb-handle-memory-hot-plug-events.patch
hugetlb-offload-per-node-attribute-registrations.patch
mm-add-gfp-flags-for-nodemask_alloc-slab-allocations.patch
do_wait-optimization-do-not-place-sub-threads-on-task_struct-children-list.patch
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