mirror of
https://github.com/team-infusion-developers/android_kernel_samsung_msm8976.git
synced 2024-10-31 18:09:19 +00:00
ksm: allocate roots when needed
It is a pity to have MAX_NUMNODES+MAX_NUMNODES tree roots statically allocated, particularly when very few users will ever actually tune merge_across_nodes 0 to use more than 1+1 of those trees. Not a big deal (only 16kB wasted on each machine with CONFIG_MAXSMP), but a pity. Start off with 1+1 statically allocated, then if merge_across_nodes is ever tuned, allocate for nr_node_ids+nr_node_ids. Do not attempt to free up the extra if it's tuned back, that would be a waste of effort. Signed-off-by: Hugh Dickins <hughd@google.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Petr Holasek <pholasek@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Izik Eidus <izik.eidus@ravellosystems.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
parent
56f31801cc
commit
ef53d16cde
1 changed files with 49 additions and 23 deletions
72
mm/ksm.c
72
mm/ksm.c
|
@ -183,8 +183,10 @@ struct rmap_item {
|
|||
#define STABLE_FLAG 0x200 /* is listed from the stable tree */
|
||||
|
||||
/* The stable and unstable tree heads */
|
||||
static struct rb_root root_unstable_tree[MAX_NUMNODES];
|
||||
static struct rb_root root_stable_tree[MAX_NUMNODES];
|
||||
static struct rb_root one_stable_tree[1] = { RB_ROOT };
|
||||
static struct rb_root one_unstable_tree[1] = { RB_ROOT };
|
||||
static struct rb_root *root_stable_tree = one_stable_tree;
|
||||
static struct rb_root *root_unstable_tree = one_unstable_tree;
|
||||
|
||||
/* Recently migrated nodes of stable tree, pending proper placement */
|
||||
static LIST_HEAD(migrate_nodes);
|
||||
|
@ -224,8 +226,10 @@ static unsigned int ksm_thread_sleep_millisecs = 20;
|
|||
#ifdef CONFIG_NUMA
|
||||
/* Zeroed when merging across nodes is not allowed */
|
||||
static unsigned int ksm_merge_across_nodes = 1;
|
||||
static int ksm_nr_node_ids = 1;
|
||||
#else
|
||||
#define ksm_merge_across_nodes 1U
|
||||
#define ksm_nr_node_ids 1
|
||||
#endif
|
||||
|
||||
#define KSM_RUN_STOP 0
|
||||
|
@ -508,7 +512,7 @@ static void remove_node_from_stable_tree(struct stable_node *stable_node)
|
|||
list_del(&stable_node->list);
|
||||
else
|
||||
rb_erase(&stable_node->node,
|
||||
&root_stable_tree[NUMA(stable_node->nid)]);
|
||||
root_stable_tree + NUMA(stable_node->nid));
|
||||
free_stable_node(stable_node);
|
||||
}
|
||||
|
||||
|
@ -644,7 +648,7 @@ static void remove_rmap_item_from_tree(struct rmap_item *rmap_item)
|
|||
BUG_ON(age > 1);
|
||||
if (!age)
|
||||
rb_erase(&rmap_item->node,
|
||||
&root_unstable_tree[NUMA(rmap_item->nid)]);
|
||||
root_unstable_tree + NUMA(rmap_item->nid));
|
||||
ksm_pages_unshared--;
|
||||
rmap_item->address &= PAGE_MASK;
|
||||
}
|
||||
|
@ -742,7 +746,7 @@ static int remove_all_stable_nodes(void)
|
|||
int nid;
|
||||
int err = 0;
|
||||
|
||||
for (nid = 0; nid < nr_node_ids; nid++) {
|
||||
for (nid = 0; nid < ksm_nr_node_ids; nid++) {
|
||||
while (root_stable_tree[nid].rb_node) {
|
||||
stable_node = rb_entry(root_stable_tree[nid].rb_node,
|
||||
struct stable_node, node);
|
||||
|
@ -1150,6 +1154,7 @@ static struct page *try_to_merge_two_pages(struct rmap_item *rmap_item,
|
|||
static struct page *stable_tree_search(struct page *page)
|
||||
{
|
||||
int nid;
|
||||
struct rb_root *root;
|
||||
struct rb_node **new;
|
||||
struct rb_node *parent;
|
||||
struct stable_node *stable_node;
|
||||
|
@ -1163,8 +1168,9 @@ static struct page *stable_tree_search(struct page *page)
|
|||
}
|
||||
|
||||
nid = get_kpfn_nid(page_to_pfn(page));
|
||||
root = root_stable_tree + nid;
|
||||
again:
|
||||
new = &root_stable_tree[nid].rb_node;
|
||||
new = &root->rb_node;
|
||||
parent = NULL;
|
||||
|
||||
while (*new) {
|
||||
|
@ -1219,7 +1225,7 @@ again:
|
|||
list_del(&page_node->list);
|
||||
DO_NUMA(page_node->nid = nid);
|
||||
rb_link_node(&page_node->node, parent, new);
|
||||
rb_insert_color(&page_node->node, &root_stable_tree[nid]);
|
||||
rb_insert_color(&page_node->node, root);
|
||||
get_page(page);
|
||||
return page;
|
||||
|
||||
|
@ -1227,11 +1233,10 @@ replace:
|
|||
if (page_node) {
|
||||
list_del(&page_node->list);
|
||||
DO_NUMA(page_node->nid = nid);
|
||||
rb_replace_node(&stable_node->node,
|
||||
&page_node->node, &root_stable_tree[nid]);
|
||||
rb_replace_node(&stable_node->node, &page_node->node, root);
|
||||
get_page(page);
|
||||
} else {
|
||||
rb_erase(&stable_node->node, &root_stable_tree[nid]);
|
||||
rb_erase(&stable_node->node, root);
|
||||
page = NULL;
|
||||
}
|
||||
stable_node->head = &migrate_nodes;
|
||||
|
@ -1250,13 +1255,15 @@ static struct stable_node *stable_tree_insert(struct page *kpage)
|
|||
{
|
||||
int nid;
|
||||
unsigned long kpfn;
|
||||
struct rb_root *root;
|
||||
struct rb_node **new;
|
||||
struct rb_node *parent = NULL;
|
||||
struct stable_node *stable_node;
|
||||
|
||||
kpfn = page_to_pfn(kpage);
|
||||
nid = get_kpfn_nid(kpfn);
|
||||
new = &root_stable_tree[nid].rb_node;
|
||||
root = root_stable_tree + nid;
|
||||
new = &root->rb_node;
|
||||
|
||||
while (*new) {
|
||||
struct page *tree_page;
|
||||
|
@ -1295,7 +1302,7 @@ static struct stable_node *stable_tree_insert(struct page *kpage)
|
|||
set_page_stable_node(kpage, stable_node);
|
||||
DO_NUMA(stable_node->nid = nid);
|
||||
rb_link_node(&stable_node->node, parent, new);
|
||||
rb_insert_color(&stable_node->node, &root_stable_tree[nid]);
|
||||
rb_insert_color(&stable_node->node, root);
|
||||
|
||||
return stable_node;
|
||||
}
|
||||
|
@ -1325,7 +1332,7 @@ struct rmap_item *unstable_tree_search_insert(struct rmap_item *rmap_item,
|
|||
int nid;
|
||||
|
||||
nid = get_kpfn_nid(page_to_pfn(page));
|
||||
root = &root_unstable_tree[nid];
|
||||
root = root_unstable_tree + nid;
|
||||
new = &root->rb_node;
|
||||
|
||||
while (*new) {
|
||||
|
@ -1422,7 +1429,7 @@ static void cmp_and_merge_page(struct page *page, struct rmap_item *rmap_item)
|
|||
if (stable_node->head != &migrate_nodes &&
|
||||
get_kpfn_nid(stable_node->kpfn) != NUMA(stable_node->nid)) {
|
||||
rb_erase(&stable_node->node,
|
||||
&root_stable_tree[NUMA(stable_node->nid)]);
|
||||
root_stable_tree + NUMA(stable_node->nid));
|
||||
stable_node->head = &migrate_nodes;
|
||||
list_add(&stable_node->list, stable_node->head);
|
||||
}
|
||||
|
@ -1574,7 +1581,7 @@ static struct rmap_item *scan_get_next_rmap_item(struct page **page)
|
|||
}
|
||||
}
|
||||
|
||||
for (nid = 0; nid < nr_node_ids; nid++)
|
||||
for (nid = 0; nid < ksm_nr_node_ids; nid++)
|
||||
root_unstable_tree[nid] = RB_ROOT;
|
||||
|
||||
spin_lock(&ksm_mmlist_lock);
|
||||
|
@ -2094,8 +2101,8 @@ static void ksm_check_stable_tree(unsigned long start_pfn,
|
|||
struct rb_node *node;
|
||||
int nid;
|
||||
|
||||
for (nid = 0; nid < nr_node_ids; nid++) {
|
||||
node = rb_first(&root_stable_tree[nid]);
|
||||
for (nid = 0; nid < ksm_nr_node_ids; nid++) {
|
||||
node = rb_first(root_stable_tree + nid);
|
||||
while (node) {
|
||||
stable_node = rb_entry(node, struct stable_node, node);
|
||||
if (stable_node->kpfn >= start_pfn &&
|
||||
|
@ -2105,7 +2112,7 @@ static void ksm_check_stable_tree(unsigned long start_pfn,
|
|||
* which is why we keep kpfn instead of page*
|
||||
*/
|
||||
remove_node_from_stable_tree(stable_node);
|
||||
node = rb_first(&root_stable_tree[nid]);
|
||||
node = rb_first(root_stable_tree + nid);
|
||||
} else
|
||||
node = rb_next(node);
|
||||
cond_resched();
|
||||
|
@ -2298,8 +2305,31 @@ static ssize_t merge_across_nodes_store(struct kobject *kobj,
|
|||
if (ksm_merge_across_nodes != knob) {
|
||||
if (ksm_pages_shared || remove_all_stable_nodes())
|
||||
err = -EBUSY;
|
||||
else
|
||||
else if (root_stable_tree == one_stable_tree) {
|
||||
struct rb_root *buf;
|
||||
/*
|
||||
* This is the first time that we switch away from the
|
||||
* default of merging across nodes: must now allocate
|
||||
* a buffer to hold as many roots as may be needed.
|
||||
* Allocate stable and unstable together:
|
||||
* MAXSMP NODES_SHIFT 10 will use 16kB.
|
||||
*/
|
||||
buf = kcalloc(nr_node_ids + nr_node_ids,
|
||||
sizeof(*buf), GFP_KERNEL | __GFP_ZERO);
|
||||
/* Let us assume that RB_ROOT is NULL is zero */
|
||||
if (!buf)
|
||||
err = -ENOMEM;
|
||||
else {
|
||||
root_stable_tree = buf;
|
||||
root_unstable_tree = buf + nr_node_ids;
|
||||
/* Stable tree is empty but not the unstable */
|
||||
root_unstable_tree[0] = one_unstable_tree[0];
|
||||
}
|
||||
}
|
||||
if (!err) {
|
||||
ksm_merge_across_nodes = knob;
|
||||
ksm_nr_node_ids = knob ? 1 : nr_node_ids;
|
||||
}
|
||||
}
|
||||
mutex_unlock(&ksm_thread_mutex);
|
||||
|
||||
|
@ -2378,15 +2408,11 @@ static int __init ksm_init(void)
|
|||
{
|
||||
struct task_struct *ksm_thread;
|
||||
int err;
|
||||
int nid;
|
||||
|
||||
err = ksm_slab_init();
|
||||
if (err)
|
||||
goto out;
|
||||
|
||||
for (nid = 0; nid < nr_node_ids; nid++)
|
||||
root_stable_tree[nid] = RB_ROOT;
|
||||
|
||||
ksm_thread = kthread_run(ksm_scan_thread, NULL, "ksmd");
|
||||
if (IS_ERR(ksm_thread)) {
|
||||
printk(KERN_ERR "ksm: creating kthread failed\n");
|
||||
|
|
Loading…
Reference in a new issue