hugetlbfs: fix hugetlb_get_unmapped_area()

Use/update cached_hole_size and free_area_cache properly to speedup
finding of a free region.

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>

diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c
index 1e85a7ac021759da6a3ad118b5c1734db0bd1cc0..b7bc7868c7b5e5977091b4314770a043c4c0d834 100644 (file)
--- a/fs/hugetlbfs/inode.c
+++ b/fs/hugetlbfs/inode.c
@@ -154,10 +154,12 @@ hugetlb_get_unmapped_area(struct file *file, unsigned long addr,
                        return addr;
        }
 
-       start_addr = mm->free_area_cache;
-
-       if (len <= mm->cached_hole_size)
+       if (len > mm->cached_hole_size)
+               start_addr = mm->free_area_cache;
+       else {
                start_addr = TASK_UNMAPPED_BASE;
+               mm->cached_hole_size = 0;
+       }
 
 full_search:
        addr = ALIGN(start_addr, huge_page_size(h));
@@ -171,13 +173,18 @@ full_search:
                         */
                        if (start_addr != TASK_UNMAPPED_BASE) {
                                start_addr = TASK_UNMAPPED_BASE;
+                               mm->cached_hole_size = 0;
                                goto full_search;
                        }
                        return -ENOMEM;
                }
 
-               if (!vma || addr + len <= vma->vm_start)
+               if (!vma || addr + len <= vma->vm_start) {
+                       mm->free_area_cache = addr + len;
                        return addr;
+               }
+               if (addr + mm->cached_hole_size < vma->vm_start)
+                       mm->cached_hole_size = vma->vm_start - addr;
                addr = ALIGN(vma->vm_end, huge_page_size(h));
        }
 }