[tip: perf/core] uprobes: Re-order struct uprobe_task to save some space
From: tip-bot2 for Christophe JAILLET
Date: Mon Nov 11 2024 - 05:58:47 EST
The following commit has been merged into the perf/core branch of tip:
Commit-ID: c554aa9ca976480839af342204e05bb4ce8367d5
Gitweb: https://git.kernel.org/tip/c554aa9ca976480839af342204e05bb4ce8367d5
Author: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx>
AuthorDate: Fri, 01 Nov 2024 22:13:33 +01:00
Committer: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
CommitterDate: Mon, 11 Nov 2024 11:49:48 +01:00
uprobes: Re-order struct uprobe_task to save some space
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.jaillet@xxxxxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Acked-by: "Masami Hiramatsu (Google)" <mhiramat@xxxxxxxxxx>
Link: https://lore.kernel.org/r/a9f541d0cedf421f765c77a1fb93d6a979778a88.1730495562.git.christophe.jaillet@xxxxxxxxxx
---
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 7a051b5..e0a4c20 100644
--- a/include/linux/uprobes.h
+++ b/include/linux/uprobes.h
@@ -121,6 +121,9 @@ struct hprobe {
struct uprobe_task {
enum uprobe_task_state state;
+ unsigned int depth;
+ struct return_instance *return_instances;
+
union {
struct {
struct arch_uprobe_task autask;
@@ -138,9 +141,6 @@ struct uprobe_task {
unsigned long xol_vaddr;
struct arch_uprobe *auprobe;
-
- struct return_instance *return_instances;
- unsigned int depth;
};
struct return_consumer {