hugetlb: try to search again if it is really needed

Search again only if some holes may be skipped in the first pass.

[akpm@linux-foundation.org: clean up crazy compound definition]
Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Hillf Danton <dhillf@gmail.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 6 insertions, 4 deletions

diff --git a/arch/x86/mm/hugetlbpage.c b/arch/x86/mm/hugetlbpage.c
index 8ecbb4bba4b3..c20e81c3425d 100644
--- a/arch/x86/mm/hugetlbpage.c
+++ b/arch/x86/mm/hugetlbpage.c
@@ -309,9 +309,10 @@ static unsigned long hugetlb_get_unmapped_area_topdown(struct file *file,
         struct hstate *h = hstate_file(file);
         struct mm_struct *mm = current->mm;
         struct vm_area_struct *vma, *prev_vma;
-        unsigned long base = mm->mmap_base, addr = addr0;
+        unsigned long base = mm->mmap_base;
+        unsigned long addr = addr0;
         unsigned long largest_hole = mm->cached_hole_size;
-        int first_time = 1;
+        unsigned long start_addr;
 
         /* don't allow allocations above current base */
         if (mm->free_area_cache > base)
@@ -322,6 +323,8 @@ static unsigned long hugetlb_get_unmapped_area_topdown(struct file *file,
                 mm->free_area_cache  = base;
         }
 try_again:
+        start_addr = mm->free_area_cache;
+
         /* make sure it can fit in the remaining address space */
         if (mm->free_area_cache < len)
                 goto fail;
@@ -368,10 +371,9 @@ fail:
          * if hint left us with no space for the requested
          * mapping then try again:
          */
-        if (first_time) {
+        if (start_addr != base) {
                 mm->free_area_cache = base;
                 largest_hole = 0;
-                first_time = 0;
                 goto try_again;
         }
         /*