The rmap walks in ksm.c are like those in rmap.c: they can safely be done with anon_vma_lock_read().
Signed-off-by: Hugh Dickins <[email protected]> --- mm/ksm.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) --- 3.7+git/mm/ksm.c 2012-12-16 16:35:08.752441527 -0800 +++ linux/mm/ksm.c 2012-12-19 16:58:05.292145790 -0800 @@ -1624,7 +1624,7 @@ again: struct anon_vma_chain *vmac; struct vm_area_struct *vma; - anon_vma_lock_write(anon_vma); + anon_vma_lock_read(anon_vma); anon_vma_interval_tree_foreach(vmac, &anon_vma->rb_root, 0, ULONG_MAX) { vma = vmac->vma; @@ -1648,7 +1648,7 @@ again: if (!search_new_forks || !mapcount) break; } - anon_vma_unlock(anon_vma); + anon_vma_unlock_read(anon_vma); if (!mapcount) goto out; } @@ -1678,7 +1678,7 @@ again: struct anon_vma_chain *vmac; struct vm_area_struct *vma; - anon_vma_lock_write(anon_vma); + anon_vma_lock_read(anon_vma); anon_vma_interval_tree_foreach(vmac, &anon_vma->rb_root, 0, ULONG_MAX) { vma = vmac->vma; @@ -1697,11 +1697,11 @@ again: ret = try_to_unmap_one(page, vma, rmap_item->address, flags); if (ret != SWAP_AGAIN || !page_mapped(page)) { - anon_vma_unlock(anon_vma); + anon_vma_unlock_read(anon_vma); goto out; } } - anon_vma_unlock(anon_vma); + anon_vma_unlock_read(anon_vma); } if (!search_new_forks++) goto again; @@ -1731,7 +1731,7 @@ again: struct anon_vma_chain *vmac; struct vm_area_struct *vma; - anon_vma_lock_write(anon_vma); + anon_vma_lock_read(anon_vma); anon_vma_interval_tree_foreach(vmac, &anon_vma->rb_root, 0, ULONG_MAX) { vma = vmac->vma; @@ -1749,11 +1749,11 @@ again: ret = rmap_one(page, vma, rmap_item->address, arg); if (ret != SWAP_AGAIN) { - anon_vma_unlock(anon_vma); + anon_vma_unlock_read(anon_vma); goto out; } } - anon_vma_unlock(anon_vma); + anon_vma_unlock_read(anon_vma); } if (!search_new_forks++) goto again; -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
