diff options
author | Michel Lespinasse <walken@google.com> | 2013-02-23 04:32:44 +0400 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2013-02-24 05:50:11 +0400 |
commit | cea10a19b7972a1954c4a2d05a7de8db48b444fb (patch) | |
tree | 694b3c906259cfbfc7b7cb1b0eb507ecf0d1d63c /mm/mlock.c | |
parent | c22c0d6344c362b1dde5d8e160d3d07536aca120 (diff) | |
download | linux-cea10a19b7972a1954c4a2d05a7de8db48b444fb.tar.xz |
mm: directly use __mlock_vma_pages_range() in find_extend_vma()
In find_extend_vma(), we don't need mlock_vma_pages_range() to verify
the vma type - we know we're working with a stack. So, we can call
directly into __mlock_vma_pages_range(), and remove the last
make_pages_present() call site.
Note that we don't use mm_populate() here, so we can't release the
mmap_sem while allocating new stack pages. This is deemed acceptable,
because the stack vmas grow by a bounded number of pages at a time, and
these are anon pages so we don't have to read from disk to populate
them.
Signed-off-by: Michel Lespinasse <walken@google.com>
Acked-by: Rik van Riel <riel@redhat.com>
Tested-by: Andy Lutomirski <luto@amacapital.net>
Cc: Greg Ungerer <gregungerer@westnet.com.au>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/mlock.c')
-rw-r--r-- | mm/mlock.c | 57 |
1 files changed, 3 insertions, 54 deletions
diff --git a/mm/mlock.c b/mm/mlock.c index a296a49865df..569400a5d079 100644 --- a/mm/mlock.c +++ b/mm/mlock.c @@ -155,9 +155,8 @@ void munlock_vma_page(struct page *page) * * vma->vm_mm->mmap_sem must be held for at least read. */ -static long __mlock_vma_pages_range(struct vm_area_struct *vma, - unsigned long start, unsigned long end, - int *nonblocking) +long __mlock_vma_pages_range(struct vm_area_struct *vma, + unsigned long start, unsigned long end, int *nonblocking) { struct mm_struct *mm = vma->vm_mm; unsigned long addr = start; @@ -202,56 +201,6 @@ static int __mlock_posix_error_return(long retval) return retval; } -/** - * mlock_vma_pages_range() - mlock pages in specified vma range. - * @vma - the vma containing the specfied address range - * @start - starting address in @vma to mlock - * @end - end address [+1] in @vma to mlock - * - * For mmap()/mremap()/expansion of mlocked vma. - * - * return 0 on success for "normal" vmas. - * - * return number of pages [> 0] to be removed from locked_vm on success - * of "special" vmas. - */ -long mlock_vma_pages_range(struct vm_area_struct *vma, - unsigned long start, unsigned long end) -{ - int nr_pages = (end - start) / PAGE_SIZE; - BUG_ON(!(vma->vm_flags & VM_LOCKED)); - - /* - * filter unlockable vmas - */ - if (vma->vm_flags & (VM_IO | VM_PFNMAP)) - goto no_mlock; - - if (!((vma->vm_flags & VM_DONTEXPAND) || - is_vm_hugetlb_page(vma) || - vma == get_gate_vma(current->mm))) { - - __mlock_vma_pages_range(vma, start, end, NULL); - - /* Hide errors from mmap() and other callers */ - return 0; - } - - /* - * User mapped kernel pages or huge pages: - * make these pages present to populate the ptes, but - * fall thru' to reset VM_LOCKED--no need to unlock, and - * return nr_pages so these don't get counted against task's - * locked limit. huge pages are already counted against - * locked vm limit. - */ - make_pages_present(start, end); - -no_mlock: - vma->vm_flags &= ~VM_LOCKED; /* and don't come back! */ - return nr_pages; /* error or pages NOT mlocked */ -} - /* * munlock_vma_pages_range() - munlock all pages in the vma range.' * @vma - vma containing range to be munlock()ed. @@ -303,7 +252,7 @@ void munlock_vma_pages_range(struct vm_area_struct *vma, * * Filters out "special" vmas -- VM_LOCKED never gets set for these, and * munlock is a no-op. However, for some special vmas, we go ahead and - * populate the ptes via make_pages_present(). + * populate the ptes. * * For vmas that pass the filters, merge/split as appropriate. */ |