hugetlbfs: per mount huge page sizes
Add the ability to configure the hugetlb hstate used on a per mount basis.
- Add a new pagesize= option to the hugetlbfs mount that allows setting
the page size
- This option causes the mount code to find the hstate corresponding to the
specified size, and sets up a pointer to the hstate in the mount's
superblock.
- Change the hstate accessors to use this information rather than the
global_hstate they were using (requires a slight change in mm/memory.c
so we don't NULL deref in the error-unmap path -- see comments).
[np: take hstate out of hugetlbfs inode and vma->vm_private_data]
Acked-by: Adam Litke <agl@us.ibm.com>
Acked-by: Nishanth Aravamudan <nacc@us.ibm.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/memory.c b/mm/memory.c
index c1c1d6d..02fc6b1 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -901,9 +901,23 @@
}
if (unlikely(is_vm_hugetlb_page(vma))) {
- unmap_hugepage_range(vma, start, end, NULL);
- zap_work -= (end - start) /
+ /*
+ * It is undesirable to test vma->vm_file as it
+ * should be non-null for valid hugetlb area.
+ * However, vm_file will be NULL in the error
+ * cleanup path of do_mmap_pgoff. When
+ * hugetlbfs ->mmap method fails,
+ * do_mmap_pgoff() nullifies vma->vm_file
+ * before calling this function to clean up.
+ * Since no pte has actually been setup, it is
+ * safe to do nothing in this case.
+ */
+ if (vma->vm_file) {
+ unmap_hugepage_range(vma, start, end, NULL);
+ zap_work -= (end - start) /
pages_per_huge_page(hstate_vma(vma));
+ }
+
start = end;
} else
start = unmap_page_range(*tlbp, vma,