thp: release page in page pre-alloc path

If NUMA is enabled, we can release the page in the page pre-alloc
operation, then the CONFIG_NUMA dependent code can be reduced

Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 7 insertions, 12 deletions

diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index d5b5fcc73c44..9c4390f60c3e 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -1873,15 +1873,12 @@ static void collapse_huge_page(struct mm_struct *mm,
                 *hpage = ERR_PTR(-ENOMEM);
                 return;
         }
+        *hpage = new_page;
         count_vm_event(THP_COLLAPSE_ALLOC);
 #endif
 
-        if (unlikely(mem_cgroup_newpage_charge(new_page, mm, GFP_KERNEL))) {
-#ifdef CONFIG_NUMA
-                put_page(new_page);
-#endif
+        if (unlikely(mem_cgroup_newpage_charge(new_page, mm, GFP_KERNEL)))
                 return;
-        }
 
         /*
          * Prevent all access to pagetables with the exception of
@@ -1982,9 +1979,8 @@ static void collapse_huge_page(struct mm_struct *mm,
         prepare_pmd_huge_pte(pgtable, mm);
         spin_unlock(&mm->page_table_lock);
 
-#ifndef CONFIG_NUMA
         *hpage = NULL;
-#endif
+
         khugepaged_pages_collapsed++;
 out_up_write:
         up_write(&mm->mmap_sem);
@@ -1992,9 +1988,6 @@ out_up_write:
 
 out:
         mem_cgroup_uncharge_page(new_page);
-#ifdef CONFIG_NUMA
-        put_page(new_page);
-#endif
         goto out_up_write;
 }
 
@@ -2260,8 +2253,6 @@ static void khugepaged_do_scan(void)
         barrier(); /* write khugepaged_pages_to_scan to local stack */
 
         while (progress < pages) {
-                cond_resched();
-
 #ifndef CONFIG_NUMA
                 if (!hpage)
                         hpage = khugepaged_alloc_hugepage(&wait);
@@ -2274,8 +2265,12 @@ static void khugepaged_do_scan(void)
                                 break;
                         wait = false;
                         khugepaged_alloc_sleep();
+                } else if (hpage) {
+                        put_page(hpage);
+                        hpage = NULL;
                 }
 #endif
+                cond_resched();
 
                 if (unlikely(kthread_should_stop() || freezing(current)))
                         break;