Now hugepages are definitely movable. So allocating hugepages from
ZONE_MOVABLE is natural and we have no reason to keep this parameter.
In order to allow userspace to prepare for the removal, let's leave
this sysctl handler as noop for a while.
ChangeLog v3:
- use WARN_ON_ONCE
ChangeLog v2:
- shift to noop function instead of completely removing the parameter
- rename patch title
Signed-off-by: Naoya Horiguchi <n-horiguchi@xxxxxxxxxxxxx>
Acked-by: Andi Kleen <ak@xxxxxxxxxxxxxxx>
Reviewed-by: Wanpeng Li <liwanp@xxxxxxxxxxxxxxxxxx>
---
Documentation/sysctl/vm.txt | 13 ++-----------
mm/hugetlb.c | 17 ++++++-----------
2 files changed, 8 insertions(+), 22 deletions(-)
diff --git v3.11-rc1.orig/Documentation/sysctl/vm.txt v3.11-rc1/Documentation/sysctl/vm.txt
index 36ecc26..6e211a1 100644
--- v3.11-rc1.orig/Documentation/sysctl/vm.txt
+++ v3.11-rc1/Documentation/sysctl/vm.txt
@@ -200,17 +200,8 @@ fragmentation index is <= extfrag_threshold. The default value is 500.
hugepages_treat_as_movable
-This parameter is only useful when kernelcore= is specified at boot time to
-create ZONE_MOVABLE for pages that may be reclaimed or migrated. Huge pages
-are not movable so are not normally allocated from ZONE_MOVABLE. A non-zero
-value written to hugepages_treat_as_movable allows huge pages to be allocated
-from ZONE_MOVABLE.
-
-Once enabled, the ZONE_MOVABLE is treated as an area of memory the huge
-pages pool can easily grow or shrink within. Assuming that applications are
-not running that mlock() a lot of memory, it is likely the huge pages pool
-can grow to the size of ZONE_MOVABLE by repeatedly entering the desired value
-into nr_hugepages and triggering page reclaim.
+This parameter is obsolete and planned to be removed. The value has no effect
+on kernel's behavior.
==============================================================
diff --git v3.11-rc1.orig/mm/hugetlb.c v3.11-rc1/mm/hugetlb.c
index 75bbdc0..30456e5 100644
--- v3.11-rc1.orig/mm/hugetlb.c
+++ v3.11-rc1/mm/hugetlb.c
@@ -34,7 +34,6 @@
#include "internal.h"
const unsigned long hugetlb_zero = 0, hugetlb_infinity = ~0UL;
-static gfp_t htlb_alloc_mask = GFP_HIGHUSER;
unsigned long hugepages_treat_as_movable;
int hugetlb_max_hstate __read_mostly;
@@ -550,7 +549,7 @@ static struct page *dequeue_huge_page_vma(struct hstate *h,
retry_cpuset:
cpuset_mems_cookie = get_mems_allowed();
zonelist = huge_zonelist(vma, address,
- htlb_alloc_mask, &mpol, &nodemask);
+ GFP_HIGHUSER_MOVABLE, &mpol, &nodemask);
/*
* A child process with MAP_PRIVATE mappings created by their parent
* have no page reserves. This check ensures that reservations are
@@ -566,7 +565,7 @@ static struct page *dequeue_huge_page_vma(struct hstate *h,
for_each_zone_zonelist_nodemask(zone, z, zonelist,
MAX_NR_ZONES - 1, nodemask) {
- if (cpuset_zone_allowed_softwall(zone, htlb_alloc_mask)) {
+ if (cpuset_zone_allowed_softwall(zone, GFP_HIGHUSER_MOVABLE)) {
page = dequeue_huge_page_node(h, zone_to_nid(zone));
if (page) {
if (!avoid_reserve)
@@ -723,7 +722,7 @@ static struct page *alloc_fresh_huge_page_node(struct hstate *h, int nid)
return NULL;
page = alloc_pages_exact_node(nid,
- htlb_alloc_mask|__GFP_COMP|__GFP_THISNODE|
+ GFP_HIGHUSER_MOVABLE|__GFP_COMP|__GFP_THISNODE|
__GFP_REPEAT|__GFP_NOWARN,
huge_page_order(h));
if (page) {
@@ -948,12 +947,12 @@ static struct page *alloc_buddy_huge_page(struct hstate *h, int nid)
spin_unlock(&hugetlb_lock);
if (nid == NUMA_NO_NODE)
- page = alloc_pages(htlb_alloc_mask|__GFP_COMP|
+ page = alloc_pages(GFP_HIGHUSER_MOVABLE|__GFP_COMP|
__GFP_REPEAT|__GFP_NOWARN,
huge_page_order(h));
else
page = alloc_pages_exact_node(nid,
- htlb_alloc_mask|__GFP_COMP|__GFP_THISNODE|
+ GFP_HIGHUSER_MOVABLE|__GFP_COMP|__GFP_THISNODE|
__GFP_REPEAT|__GFP_NOWARN, huge_page_order(h));
if (page && arch_prepare_hugepage(page)) {
@@ -2132,11 +2131,7 @@ int hugetlb_treat_movable_handler(struct ctl_table *table, int write,
void __user *buffer,
size_t *length, loff_t *ppos)
{
- proc_dointvec(table, write, buffer, length, ppos);
- if (hugepages_treat_as_movable)
- htlb_alloc_mask = GFP_HIGHUSER_MOVABLE;
- else
- htlb_alloc_mask = GFP_HIGHUSER;
+ WARN_ON_ONCE("This knob is obsolete and has no effect. It is scheduled for removal.\n");
return 0;
}
--
1.8.3.1
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