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>

diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 0af19ff..078832c 100644 (file)
--- 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;