mm/compaction: split freepages without holding the zone lock
We don't need to split freepages with holding the zone lock. It will
cause more contention on zone lock so not desirable.
[rientjes@google.com: if __isolate_free_page() fails, avoid adding to freelist so we don't call map_pages() with it]
Link: http://lkml.kernel.org/r/alpine.DEB.2.10.1606211447001.43430@chino.kir.corp.google.com
Link: http://lkml.kernel.org/r/1464230275-25791-1-git-send-email-iamjoonsoo.kim@lge.com
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Alexander Potapenko <glider@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/compaction.c b/mm/compaction.c
index 6095055..3cda954 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -64,13 +64,31 @@
static void map_pages(struct list_head *list)
{
- struct page *page;
+ unsigned int i, order, nr_pages;
+ struct page *page, *next;
+ LIST_HEAD(tmp_list);
- list_for_each_entry(page, list, lru) {
- arch_alloc_page(page, 0);
- kernel_map_pages(page, 1, 1);
- kasan_alloc_pages(page, 0);
+ list_for_each_entry_safe(page, next, list, lru) {
+ list_del(&page->lru);
+
+ order = page_private(page);
+ nr_pages = 1 << order;
+ set_page_private(page, 0);
+ set_page_refcounted(page);
+
+ arch_alloc_page(page, order);
+ kernel_map_pages(page, nr_pages, 1);
+ kasan_alloc_pages(page, order);
+ if (order)
+ split_page(page, order);
+
+ for (i = 0; i < nr_pages; i++) {
+ list_add(&page->lru, &tmp_list);
+ page++;
+ }
}
+
+ list_splice(&tmp_list, list);
}
static inline bool migrate_async_suitable(int migratetype)
@@ -405,12 +423,13 @@
unsigned long flags = 0;
bool locked = false;
unsigned long blockpfn = *start_pfn;
+ unsigned int order;
cursor = pfn_to_page(blockpfn);
/* Isolate free pages. */
for (; blockpfn < end_pfn; blockpfn++, cursor++) {
- int isolated, i;
+ int isolated;
struct page *page = cursor;
/*
@@ -476,17 +495,17 @@
goto isolate_fail;
}
- /* Found a free page, break it into order-0 pages */
- isolated = split_free_page(page);
+ /* Found a free page, will break it into order-0 pages */
+ order = page_order(page);
+ isolated = __isolate_free_page(page, order);
if (!isolated)
break;
+ set_page_private(page, order);
total_isolated += isolated;
cc->nr_freepages += isolated;
- for (i = 0; i < isolated; i++) {
- list_add(&page->lru, freelist);
- page++;
- }
+ list_add_tail(&page->lru, freelist);
+
if (!strict && cc->nr_migratepages <= cc->nr_freepages) {
blockpfn += isolated;
break;
@@ -605,7 +624,7 @@
*/
}
- /* split_free_page does not map the pages */
+ /* __isolate_free_page() does not map the pages */
map_pages(&freelist);
if (pfn < end_pfn) {
@@ -1102,7 +1121,7 @@
}
}
- /* split_free_page does not map the pages */
+ /* __isolate_free_page() does not map the pages */
map_pages(freelist);
/*