[PATCH] riscv: make thread_info smaller for RV64
From: Jisheng Zhang
Date: Fri Oct 09 2026 - 20:20:31 EST
On RV64 platforms, the thread_info structure is non-necessary bigger
due to padding. Move the "cpu" member to "preempt_count" to remove
the padding.
when !SHADOW_CALL_STACK and !RISCV_USER_CFI
Before the patch, sizeof(struct thread_info) == 72
After the patch, sizeof(struct thread_info) == 64
Signed-off-by: Jisheng Zhang <jszhang@xxxxxxxxxx>
---
arch/riscv/include/asm/thread_info.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/riscv/include/asm/thread_info.h b/arch/riscv/include/asm/thread_info.h
index 55019fdfa9ec..9f358c3ddeb0 100644
--- a/arch/riscv/include/asm/thread_info.h
+++ b/arch/riscv/include/asm/thread_info.h
@@ -53,6 +53,7 @@
struct thread_info {
unsigned long flags; /* low level flags */
int preempt_count; /* 0=>preemptible, <0=>BUG */
+ int cpu;
/*
* These stack pointers are overwritten on every system call or
* exception. SP is also saved to the stack it can be recovered when
@@ -60,7 +61,6 @@ struct thread_info {
*/
long kernel_sp; /* Kernel stack pointer */
long user_sp; /* User stack pointer */
- int cpu;
unsigned long syscall_work; /* SYSCALL_WORK_ flags */
#ifdef CONFIG_SHADOW_CALL_STACK
void *scs_base;
--
2.51.0