On Fri, 1 Nov 2024 22:13:33 +0100
Christophe JAILLET <christophe.jaillet@xxxxxxxxxx> wrote:
> On x86_64, with allmodconfig, struct uprobe_task is 72 bytes long, with a
> hole and some padding.
>
> /* size: 72, cachelines: 2, members: 7 */
> /* sum members: 64, holes: 1, sum holes: 4 */
> /* padding: 4 */
> /* forced alignments: 1, forced holes: 1, sum forced holes: 4 */
> /* last cacheline: 8 bytes */
>
> Reorder the structure to fill the hole and avoid the padding.
>
> This way, the whole structure fits in a single cacheline and some memory is
> saved when it is allocated.
>
> /* size: 64, cachelines: 1, members: 7 */
> /* forced alignments: 1 */
>
Looks good to me.
Acked-by: Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx>
Thank you!
> Signed-off-by: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx>
> ---
> Compile tested only
> ---
> include/linux/uprobes.h | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/include/linux/uprobes.h b/include/linux/uprobes.h
> index dbaf04189548..c684a470477f 100644
> --- a/include/linux/uprobes.h
> +++ b/include/linux/uprobes.h
> @@ -73,6 +73,9 @@ enum uprobe_task_state {
> struct uprobe_task {
> enum uprobe_task_state state;
>
> + unsigned int depth;
> + struct return_instance *return_instances;
> +
> union {
> struct {
> struct arch_uprobe_task autask;
> @@ -89,9 +92,6 @@ struct uprobe_task {
> unsigned long xol_vaddr;
>
> struct arch_uprobe *auprobe;
> -
> - struct return_instance *return_instances;
> - unsigned int depth;
> };
>
> struct return_consumer {
> --
> 2.47.0
>
--
Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx>
