thp: cleanup khugepaged startup

Few trivial cleanups:

 - no need to call set_recommended_min_free_kbytes() from
   late_initcall() -- start_khugepaged() calls it;

 - no need to call set_recommended_min_free_kbytes() from
   start_khugepaged() if khugepaged is not started;

 - there isn't much point in running start_khugepaged() if we've just
   set transparent_hugepage_flags to zero;

 - start_khugepaged() is misnamed -- it also used to stop the thread;

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 8 insertions, 10 deletions

diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 0af19fffe1df..078832cf3636 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -110,10 +110,6 @@ static int set_recommended_min_free_kbytes(void)
         int nr_zones = 0;
         unsigned long recommended_min;
 
-        /* khugepaged thread has stopped to failed to start */
-        if (!khugepaged_thread)
-                return 0;
-
         for_each_populated_zone(zone)
                 nr_zones++;
 
@@ -145,9 +141,8 @@ static int set_recommended_min_free_kbytes(void)
         setup_per_zone_wmarks();
         return 0;
 }
-late_initcall(set_recommended_min_free_kbytes);
 
-static int start_khugepaged(void)
+static int start_stop_khugepaged(void)
 {
         int err = 0;
         if (khugepaged_enabled()) {
@@ -158,6 +153,7 @@ static int start_khugepaged(void)
                         pr_err("khugepaged: kthread_run(khugepaged) failed\n");
                         err = PTR_ERR(khugepaged_thread);
                         khugepaged_thread = NULL;
+                        goto fail;
                 }
 
                 if (!list_empty(&khugepaged_scan.mm_head))
@@ -168,7 +164,7 @@ static int start_khugepaged(void)
                 kthread_stop(khugepaged_thread);
                 khugepaged_thread = NULL;
         }
-
+fail:
         return err;
 }
 
@@ -302,7 +298,7 @@ static ssize_t enabled_store(struct kobject *kobj,
                 int err;
 
                 mutex_lock(&khugepaged_mutex);
-                err = start_khugepaged();
+                err = start_stop_khugepaged();
                 mutex_unlock(&khugepaged_mutex);
 
                 if (err)
@@ -651,10 +647,12 @@ static int __init hugepage_init(void)
          * where the extra memory used could hurt more than TLB overhead
          * is likely to save.  The admin can still enable it through /sys.
          */
-        if (totalram_pages < (512 << (20 - PAGE_SHIFT)))
+        if (totalram_pages < (512 << (20 - PAGE_SHIFT))) {
                 transparent_hugepage_flags = 0;
+                return 0;
+        }
 
-        err = start_khugepaged();
+        err = start_stop_khugepaged();
         if (err)
                 goto err_khugepaged;