1 files changed, 19 insertions, 5 deletions

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index d4096f4a5c1f..7e5e775e97f4 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -2507,10 +2507,6 @@ void drain_all_pages(struct zone *zone)
         if (WARN_ON_ONCE(!mm_percpu_wq))
                 return;
 
-        /* Workqueues cannot recurse */
-        if (current->flags & PF_WQ_WORKER)
-                return;
-
         /*
          * Do not drain if one is already in progress unless it's specific to
          * a zone. Such callers are primarily CMA and memory hotplug and need
@@ -2688,6 +2684,7 @@ void free_unref_page_list(struct list_head *list)
 {
         struct page *page, *next;
         unsigned long flags, pfn;
+        int batch_count = 0;
 
         /* Prepare pages for freeing */
         list_for_each_entry_safe(page, next, list, lru) {
@@ -2704,6 +2701,16 @@ void free_unref_page_list(struct list_head *list)
                 set_page_private(page, 0);
                 trace_mm_page_free_batched(page);
                 free_unref_page_commit(page, pfn);
+
+                /*
+                 * Guard against excessive IRQ disabled times when we get
+                 * a large list of pages to free.
+                 */
+                if (++batch_count == SWAP_CLUSTER_MAX) {
+                        local_irq_restore(flags);
+                        batch_count = 0;
+                        local_irq_save(flags);
+                }
         }
         local_irq_restore(flags);
 }
@@ -7656,11 +7663,18 @@ int alloc_contig_range(unsigned long start, unsigned long end,
 
         /*
          * In case of -EBUSY, we'd like to know which page causes problem.
-         * So, just fall through. We will check it in test_pages_isolated().
+         * So, just fall through. test_pages_isolated() has a tracepoint
+         * which will report the busy page.
+         *
+         * It is possible that busy pages could become available before
+         * the call to test_pages_isolated, and the range will actually be
+         * allocated.  So, if we fall through be sure to clear ret so that
+         * -EBUSY is not accidentally used or returned to caller.
          */
         ret = __alloc_contig_migrate_range(&cc, start, end);
         if (ret && ret != -EBUSY)
                 goto done;
+        ret =0;
 
         /*
          * Pages from [start, end) are within a MAX_ORDER_NR_PAGES