From: Zi Yan <z...@nvidia.com>
Users are expected to set memcg max size to reflect their memory
resource allocation policy. The syscall simply migrates pages belong
to the application's memcg between from_node to to_node, where
from_node is considered fast memory and to_node is considered slow
memory. In common cases, active(hot) pages are migrated from to_node
to from_node and inactive(cold) pages are migrated from from_node to
to_node.
Separate migration for base pages and huge pages to achieve high
throughput.
1. They are migrated via different calls.
2. 4KB base pages are not transferred via multi-threaded.
3. All pages are migrated together if no optimization is used.
Signed-off-by: Zi Yan <z...@nvidia.com>
---
mm/memory_manage.c | 275 +++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 275 insertions(+)
diff --git a/mm/memory_manage.c b/mm/memory_manage.c
index e8dddbf..d63ad25 100644
--- a/mm/memory_manage.c
+++ b/mm/memory_manage.c
@@ -6,6 +6,7 @@
#include <linux/cpuset.h>
#include <linux/mempolicy.h>
#include <linux/memcontrol.h>
+#include <linux/migrate.h>
#include <linux/mm_inline.h>
#include <linux/nodemask.h>
#include <linux/rmap.h>
@@ -15,6 +16,11 @@
#include "internal.h"
+enum isolate_action {
+ ISOLATE_COLD_PAGES = 1,
+ ISOLATE_HOT_PAGES,
+ ISOLATE_HOT_AND_COLD_PAGES,
+};
static unsigned long shrink_lists_node_memcg(pg_data_t *pgdat,
struct mem_cgroup *memcg, unsigned long nr_to_scan)
@@ -78,6 +84,272 @@ static int shrink_lists(struct task_struct *p, struct
mm_struct *mm,
return err;
}
+static unsigned long isolate_pages_from_lru_list(pg_data_t *pgdat,
+ struct mem_cgroup *memcg, unsigned long nr_pages,
+ struct list_head *base_page_list,
+ struct list_head *huge_page_list,
+ unsigned long *nr_taken_base_page,
+ unsigned long *nr_taken_huge_page,
+ enum isolate_action action)
+{
+ struct lruvec *lruvec = mem_cgroup_lruvec(pgdat, memcg);
+ enum lru_list lru;
+ unsigned long nr_all_taken = 0;
+
+ if (nr_pages == ULONG_MAX)
+ nr_pages = memcg_size_node(memcg, pgdat->node_id);
+
+ lru_add_drain_all();
+
+ for_each_evictable_lru(lru) {
+ unsigned long nr_scanned, nr_taken;
+ int file = is_file_lru(lru);
+ struct scan_control sc = {.may_unmap = 1};
+
+ if (action == ISOLATE_COLD_PAGES && is_active_lru(lru))
+ continue;
+ if (action == ISOLATE_HOT_PAGES && !is_active_lru(lru))
+ continue;
+
+ spin_lock_irq(&pgdat->lru_lock);
+
+ /* Isolate base pages */
+ sc.isolate_only_base_page = 1;
+ nr_taken = isolate_lru_pages(nr_pages, lruvec, base_page_list,
+ &nr_scanned, &sc, lru);
+ /* Isolate huge pages */
+ sc.isolate_only_base_page = 0;
+ sc.isolate_only_huge_page = 1;
+ nr_taken += isolate_lru_pages(nr_pages - nr_scanned, lruvec,
+ huge_page_list, &nr_scanned, &sc, lru);
+
+ __mod_node_page_state(pgdat, NR_ISOLATED_ANON + file, nr_taken);
+
+ spin_unlock_irq(&pgdat->lru_lock);
+
+ nr_all_taken += nr_taken;
+
+ if (nr_all_taken > nr_pages)
+ break;
+ }
+
+ return nr_all_taken;
+}
+
+static int migrate_to_node(struct list_head *page_list, int nid,
+ enum migrate_mode mode)
+{
+ bool migrate_concur = mode & MIGRATE_CONCUR;
+ int num = 0;
+ int from_nid;
+ int err;
+
+ if (list_empty(page_list))
+ return num;
+
+ from_nid = page_to_nid(list_first_entry(page_list, struct page, lru));
+
+ if (migrate_concur)
+ err = migrate_pages_concur(page_list, alloc_new_node_page,
+ NULL, nid, mode, MR_SYSCALL);
+ else
+ err = migrate_pages(page_list, alloc_new_node_page,
+ NULL, nid, mode, MR_SYSCALL);
+
+ if (err) {
+ struct page *page;
+
+ list_for_each_entry(page, page_list, lru)
+ num += hpage_nr_pages(page);
+ pr_debug("%d pages failed to migrate from %d to %d\n",
+ num, from_nid, nid);
+
+ putback_movable_pages(page_list);
+ }
+ return num;
+}
+
+static inline int _putback_overflow_pages(unsigned long max_nr_pages,
+ struct list_head *page_list, unsigned long *nr_remaining_pages)
+{
+ struct page *page;
+ LIST_HEAD(putback_list);
+
+ if (list_empty(page_list))
+ return max_nr_pages;
+
+ *nr_remaining_pages = 0;
+ /* in case we need to drop the whole list */
+ page = list_first_entry(page_list, struct page, lru);
+ if (max_nr_pages <= (2 * hpage_nr_pages(page))) {
+ max_nr_pages = 0;
+ putback_movable_pages(page_list);
+ goto out;
+ }
+
+ list_for_each_entry(page, page_list, lru) {
+ int nr_pages = hpage_nr_pages(page);
+ /* drop just one more page to avoid using up free space */
+ if (max_nr_pages <= (2 * nr_pages)) {
+ max_nr_pages = 0;
+ break;
+ }
+ max_nr_pages -= nr_pages;
+ *nr_remaining_pages += nr_pages;
+ }
+
+ /* we did not scan all pages in page_list, we need to put back some */
+ if (&page->lru != page_list) {
+ list_cut_position(&putback_list, page_list, &page->lru);
+ putback_movable_pages(page_list);
+ list_splice(&putback_list, page_list);
+ }
+out:
+ return max_nr_pages;
+}
+
+static int putback_overflow_pages(unsigned long max_nr_base_pages,
+ unsigned long max_nr_huge_pages,
+ long nr_free_pages,
+ struct list_head *base_page_list,
+ struct list_head *huge_page_list,
+ unsigned long *nr_base_pages,
+ unsigned long *nr_huge_pages)
+{
+ if (nr_free_pages < 0) {
+ if ((-nr_free_pages) > max_nr_base_pages) {
+ nr_free_pages += max_nr_base_pages;
+ max_nr_base_pages = 0;
+ }
+
+ if ((-nr_free_pages) > max_nr_huge_pages) {
+ nr_free_pages = 0;
+ max_nr_base_pages = 0;
+ }
+ }
+ /*
+ * counting pages in page lists and substract the number from max_nr_*
+ * when max_nr_* go to zero, drop the remaining pages
+ */
+ max_nr_huge_pages += _putback_overflow_pages(nr_free_pages/2 +
max_nr_base_pages,
+ base_page_list, nr_base_pages);
+ return _putback_overflow_pages(nr_free_pages/2 + max_nr_huge_pages,
+ huge_page_list, nr_huge_pages);
+}
+
+static int do_mm_manage(struct task_struct *p, struct mm_struct *mm,
+ const nodemask_t *slow, const nodemask_t *fast,
+ unsigned long nr_pages, int flags)
+{
+ bool migrate_mt = flags & MPOL_MF_MOVE_MT;
+ bool migrate_concur = flags & MPOL_MF_MOVE_CONCUR;
+ bool migrate_dma = flags & MPOL_MF_MOVE_DMA;
+ bool move_hot_and_cold_pages = flags & MPOL_MF_MOVE_ALL;
+ struct mem_cgroup *memcg = mem_cgroup_from_task(p);
+ int err = 0;
+ unsigned long nr_isolated_slow_pages;
+ unsigned long nr_isolated_slow_base_pages = 0;
+ unsigned long nr_isolated_slow_huge_pages = 0;
+ unsigned long nr_isolated_fast_pages;
+ /* in case no migration from to node, we migrate all isolated pages from
+ * slow node */
+ unsigned long nr_isolated_fast_base_pages = ULONG_MAX;
+ unsigned long nr_isolated_fast_huge_pages = ULONG_MAX;
+ unsigned long max_nr_pages_fast_node, nr_pages_fast_node;
+ unsigned long nr_pages_slow_node, nr_active_pages_slow_node;
+ long nr_free_pages_fast_node;
+ int slow_nid, fast_nid;
+ enum migrate_mode mode = MIGRATE_SYNC |
+ (migrate_mt ? MIGRATE_MT : MIGRATE_SINGLETHREAD) |
+ (migrate_dma ? MIGRATE_DMA : MIGRATE_SINGLETHREAD) |
+ (migrate_concur ? MIGRATE_CONCUR : MIGRATE_SINGLETHREAD);
+ enum isolate_action isolate_action =
+
move_hot_and_cold_pages?ISOLATE_HOT_AND_COLD_PAGES:ISOLATE_HOT_PAGES;
+ LIST_HEAD(slow_base_page_list);
+ LIST_HEAD(slow_huge_page_list);
+
+ if (!memcg)
+ return 0;
+ /* Let's handle simplest situation first */
+ if (!(nodes_weight(*slow) == 1 && nodes_weight(*fast) == 1))
+ return 0;
+
+ /* Only work on specific cgroup not the global root */
+ if (memcg == root_mem_cgroup)
+ return 0;
+
+ slow_nid = first_node(*slow);
+ fast_nid = first_node(*fast);
+
+ max_nr_pages_fast_node = memcg_max_size_node(memcg, fast_nid);
+ nr_pages_fast_node = memcg_size_node(memcg, fast_nid);
+ nr_active_pages_slow_node = active_inactive_size_memcg_node(memcg,
+ slow_nid, true);
+ nr_pages_slow_node = memcg_size_node(memcg, slow_nid);
+
+ nr_free_pages_fast_node = max_nr_pages_fast_node - nr_pages_fast_node;
+
+ /* do not migrate in more pages than fast node can hold */
+ nr_pages = min_t(unsigned long, max_nr_pages_fast_node, nr_pages);
+ /* do not migrate away more pages than slow node has */
+ nr_pages = min_t(unsigned long, nr_pages_slow_node, nr_pages);
+
+ /* if fast node has enough space, migrate all possible pages in slow
node */
+ if (nr_pages != ULONG_MAX &&
+ nr_free_pages_fast_node > 0 &&
+ nr_active_pages_slow_node < nr_free_pages_fast_node) {
+ isolate_action = ISOLATE_HOT_AND_COLD_PAGES;
+ }
+
+ nr_isolated_slow_pages =
isolate_pages_from_lru_list(NODE_DATA(slow_nid),
+ memcg, nr_pages, &slow_base_page_list,
&slow_huge_page_list,
+ &nr_isolated_slow_base_pages,
&nr_isolated_slow_huge_pages,
+ isolate_action);
+
+ if (max_nr_pages_fast_node != ULONG_MAX &&
+ (nr_free_pages_fast_node < 0 ||
+ nr_free_pages_fast_node < nr_isolated_slow_pages)) {
+ LIST_HEAD(fast_base_page_list);
+ LIST_HEAD(fast_huge_page_list);
+
+ nr_isolated_fast_base_pages = 0;
+ nr_isolated_fast_huge_pages = 0;
+ /* isolate pages on fast node to make space */
+ nr_isolated_fast_pages =
isolate_pages_from_lru_list(NODE_DATA(fast_nid),
+ memcg,
+ nr_isolated_slow_pages - nr_free_pages_fast_node,
+ &fast_base_page_list, &fast_huge_page_list,
+ &nr_isolated_fast_base_pages,
&nr_isolated_fast_huge_pages,
+
move_hot_and_cold_pages?ISOLATE_HOT_AND_COLD_PAGES:ISOLATE_COLD_PAGES);
+
+ /* Migrate pages to slow node */
+ /* No multi-threaded migration for base pages */
+ nr_isolated_fast_base_pages -=
+ migrate_to_node(&fast_base_page_list, slow_nid, mode &
~MIGRATE_MT);
+
+ nr_isolated_fast_huge_pages -=
+ migrate_to_node(&fast_huge_page_list, slow_nid, mode);
+ }
+
+ if (nr_isolated_fast_base_pages != ULONG_MAX &&
+ nr_isolated_fast_huge_pages != ULONG_MAX)
+ putback_overflow_pages(nr_isolated_fast_base_pages,
+ nr_isolated_fast_huge_pages,
nr_free_pages_fast_node,
+ &slow_base_page_list, &slow_huge_page_list,
+ &nr_isolated_slow_base_pages,
+ &nr_isolated_slow_huge_pages);
+
+ /* Migrate pages to fast node */
+ /* No multi-threaded migration for base pages */
+ nr_isolated_slow_base_pages -=
+ migrate_to_node(&slow_base_page_list, fast_nid, mode &
~MIGRATE_MT);
+
+ nr_isolated_slow_huge_pages -=
+ migrate_to_node(&slow_huge_page_list, fast_nid, mode);
+
+ return err;
+}
+
SYSCALL_DEFINE6(mm_manage, pid_t, pid, unsigned long, nr_pages,
unsigned long, maxnode,
const unsigned long __user *, slow_nodes,
@@ -167,6 +439,9 @@ SYSCALL_DEFINE6(mm_manage, pid_t, pid, unsigned long,
nr_pages,
if (flags & MPOL_MF_SHRINK_LISTS)
shrink_lists(task, mm, slow, fast, nr_pages);
+ if (flags & MPOL_MF_MOVE)
+ err = do_mm_manage(task, mm, slow, fast, nr_pages, flags);
+
clear_bit(MMF_MM_MANAGE, &mm->flags);
mmput(mm);
out:
--
2.7.4
