On Fri, Jul 01, 2016 at 02:41:01PM +0800, Ganesh Mahendran wrote:
> the obj index value should be updated after return from
> find_alloced_obj()
to avoid CPU buring caused by unnecessary object scanning.
Description should include what's the goal.
>
> Signed-off-by: Ganesh Mahendran <opensource.gan...@gmail.com>
> ---
> mm/zsmalloc.c | 13 ++++++++-----
> 1 file changed, 8 insertions(+), 5 deletions(-)
>
> diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c
> index 405baa5..5c96ed1 100644
> --- a/mm/zsmalloc.c
> +++ b/mm/zsmalloc.c
> @@ -1744,15 +1744,16 @@ static void zs_object_copy(struct size_class *class,
> unsigned long dst,
> * return handle.
> */
> static unsigned long find_alloced_obj(struct size_class *class,
> - struct page *page, int index)
> + struct page *page, int *index)
> {
> unsigned long head;
> int offset = 0;
> + int objidx = *index;
Nit:
We have used obj_idx so I prefer it for consistency with others.
Suggestion:
Could you mind changing index in zs_compact_control and
migrate_zspage with obj_idx in this chance?
Strictly speaking, such clean up is separate patch but I don't mind
mixing them here(Of course, you will send it as another clean up patch,
it would be better). If you mind, just let it leave as is. Sometime,
I wil do it.
> unsigned long handle = 0;
> void *addr = kmap_atomic(page);
>
> offset = get_first_obj_offset(page);
> - offset += class->size * index;
> + offset += class->size * objidx;
>
> while (offset < PAGE_SIZE) {
> head = obj_to_head(page, addr + offset);
> @@ -1764,9 +1765,11 @@ static unsigned long find_alloced_obj(struct
> size_class *class,
> }
>
> offset += class->size;
> - index++;
> + objidx++;
> }
>
> + *index = objidx;
We can do this out of kmap section right before returing handle.
Thanks!
> +
> kunmap_atomic(addr);
> return handle;
> }
> @@ -1794,11 +1797,11 @@ static int migrate_zspage(struct zs_pool *pool,
> struct size_class *class,
> unsigned long handle;
> struct page *s_page = cc->s_page;
> struct page *d_page = cc->d_page;
> - unsigned long index = cc->index;
> + unsigned int index = cc->index;
> int ret = 0;
>
> while (1) {
> - handle = find_alloced_obj(class, s_page, index);
> + handle = find_alloced_obj(class, s_page, &index);
> if (!handle) {
> s_page = get_next_page(s_page);
> if (!s_page)
> --
> 1.9.1
>
