staging: zsmalloc: add single-page object fastpath in unmap

Improve zs_unmap_object() performance by adding a fast path for
objects that don't span pages.

Signed-off-by: Seth Jennings <sjenning@linux.vnet.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Seth Jennings 2012-07-02 16:15:50 -05:00 committed by Greg Kroah-Hartman
parent 5f601902c6
commit 103123305c

View File

@ -774,6 +774,7 @@ void *zs_map_object(struct zs_pool *pool, unsigned long handle)
}
zs_copy_map_object(area->vm_buf, page, off, class->size);
area->vm_addr = NULL;
return area->vm_buf;
}
EXPORT_SYMBOL_GPL(zs_map_object);
@ -788,6 +789,14 @@ void zs_unmap_object(struct zs_pool *pool, unsigned long handle)
struct size_class *class;
struct mapping_area *area;
area = &__get_cpu_var(zs_map_area);
if (area->vm_addr) {
/* single-page object fastpath */
kunmap_atomic(area->vm_addr);
put_cpu_var(zs_map_area);
return;
}
BUG_ON(!handle);
obj_handle_to_location(handle, &page, &obj_idx);
@ -795,11 +804,7 @@ void zs_unmap_object(struct zs_pool *pool, unsigned long handle)
class = &pool->size_class[class_idx];
off = obj_idx_to_offset(page, obj_idx, class->size);
area = &__get_cpu_var(zs_map_area);
if (off + class->size <= PAGE_SIZE)
kunmap_atomic(area->vm_addr);
else
zs_copy_unmap_object(area->vm_buf, page, off, class->size);
zs_copy_unmap_object(area->vm_buf, page, off, class->size);
put_cpu_var(zs_map_area);
}
EXPORT_SYMBOL_GPL(zs_unmap_object);