[PATCH 2/3] mm: Enable HugeTLB allocation isolation for CDM nodes

From: Anshuman Khandual
Date: Wed Feb 08 2017 - 12:30:52 EST


HugeTLB allocation/release/accounting currently spans across all the nodes
under N_MEMORY node mask. Coherent memory nodes should not be part of these
allocations. So use system_mem_nodemask() call to fetch system RAM only
nodes on the platform which can then be used for HugeTLB allocation purpose
instead of N_MEMORY node mask. This isolates coherent device memory nodes
from HugeTLB allocations.

Signed-off-by: Anshuman Khandual <khandual@xxxxxxxxxxxxxxxxxx>
---
mm/hugetlb.c | 25 ++++++++++++++++---------
1 file changed, 16 insertions(+), 9 deletions(-)

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index c7025c1..9a46d9f 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -1790,6 +1790,7 @@ static void return_unused_surplus_pages(struct hstate *h,
unsigned long unused_resv_pages)
{
unsigned long nr_pages;
+ nodemask_t system_mem = system_mem_nodemask();

/* Cannot return gigantic pages currently */
if (hstate_is_gigantic(h))
@@ -1816,7 +1817,7 @@ static void return_unused_surplus_pages(struct hstate *h,
while (nr_pages--) {
h->resv_huge_pages--;
unused_resv_pages--;
- if (!free_pool_huge_page(h, &node_states[N_MEMORY], 1))
+ if (!free_pool_huge_page(h, &system_mem, 1))
goto out;
cond_resched_lock(&hugetlb_lock);
}
@@ -2107,8 +2108,9 @@ int __weak alloc_bootmem_huge_page(struct hstate *h)
{
struct huge_bootmem_page *m;
int nr_nodes, node;
+ nodemask_t system_mem = system_mem_nodemask();

- for_each_node_mask_to_alloc(h, nr_nodes, node, &node_states[N_MEMORY]) {
+ for_each_node_mask_to_alloc(h, nr_nodes, node, &system_mem) {
void *addr;

addr = memblock_virt_alloc_try_nid_nopanic(
@@ -2177,13 +2179,14 @@ static void __init gather_bootmem_prealloc(void)
static void __init hugetlb_hstate_alloc_pages(struct hstate *h)
{
unsigned long i;
+ nodemask_t system_mem = system_mem_nodemask();
+

for (i = 0; i < h->max_huge_pages; ++i) {
if (hstate_is_gigantic(h)) {
if (!alloc_bootmem_huge_page(h))
break;
- } else if (!alloc_fresh_huge_page(h,
- &node_states[N_MEMORY]))
+ } else if (!alloc_fresh_huge_page(h, &system_mem))
break;
}
h->max_huge_pages = i;
@@ -2420,6 +2423,8 @@ static ssize_t __nr_hugepages_store_common(bool obey_mempolicy,
unsigned long count, size_t len)
{
int err;
+ nodemask_t system_mem = system_mem_nodemask();
+
NODEMASK_ALLOC(nodemask_t, nodes_allowed, GFP_KERNEL | __GFP_NORETRY);

if (hstate_is_gigantic(h) && !gigantic_page_supported()) {
@@ -2434,7 +2439,7 @@ static ssize_t __nr_hugepages_store_common(bool obey_mempolicy,
if (!(obey_mempolicy &&
init_nodemask_of_mempolicy(nodes_allowed))) {
NODEMASK_FREE(nodes_allowed);
- nodes_allowed = &node_states[N_MEMORY];
+ nodes_allowed = &system_mem;
}
} else if (nodes_allowed) {
/*
@@ -2444,11 +2449,11 @@ static ssize_t __nr_hugepages_store_common(bool obey_mempolicy,
count += h->nr_huge_pages - h->nr_huge_pages_node[nid];
init_nodemask_of_node(nodes_allowed, nid);
} else
- nodes_allowed = &node_states[N_MEMORY];
+ nodes_allowed = &system_mem;

h->max_huge_pages = set_max_huge_pages(h, count, nodes_allowed);

- if (nodes_allowed != &node_states[N_MEMORY])
+ if (nodes_allowed != &system_mem)
NODEMASK_FREE(nodes_allowed);

return len;
@@ -2745,9 +2750,10 @@ static void hugetlb_register_node(struct node *node)
*/
static void __init hugetlb_register_all_nodes(void)
{
+ nodemask_t nodes = system_mem_nodemask();
int nid;

- for_each_node_state(nid, N_MEMORY) {
+ for_each_node_mask(nid, nodes) {
struct node *node = node_devices[nid];
if (node->dev.id == nid)
hugetlb_register_node(node);
@@ -3019,11 +3025,12 @@ void hugetlb_show_meminfo(void)
{
struct hstate *h;
int nid;
+ nodemask_t system_mem = system_mem_nodemask();

if (!hugepages_supported())
return;

- for_each_node_state(nid, N_MEMORY)
+ for_each_node_mask(nid, system_mem)
for_each_hstate(h)
pr_info("Node %d hugepages_total=%u hugepages_free=%u hugepages_surp=%u hugepages_size=%lukB\n",
nid,
--
2.9.3