[PATCH] uprobes: Re-order struct uprobe_task to save some space

[Christophe JAILLET]

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 */

Signed-off-by: Christophe JAILLET <christophe.jail...@wanadoo.fr>
---
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