[PATCH 1/5] hugetlbfs: fix hugetlb_get_unmapped_area

From: Xiao Guangrong
Date: Fri Jan 13 2012 - 06:46:36 EST


Using/updating cached_hole_size and free_area_cache properly to speedup
find free region

Signed-off-by: Xiao Guangrong <xiaoguangrong@xxxxxxxxxxxxxxxxxx>
---
fs/hugetlbfs/inode.c | 15 +++++++++++----
1 files changed, 11 insertions(+), 4 deletions(-)

diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c
index e425ad9..9e0794a 100644
--- 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));
}
}
--
1.7.7.5

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