From: Xiangyou Xie xiexiangyou@huawei.com
hulk inclusion category: feature bugzilla: NA CVE: NA
When it is to wake up a task in a remote cpu shared LLC , we can simply set need_resched flag, waking up a cpu that is in polling idle. This wakeup action does not require an IPI.
But the premise is that it need to support _TIF_POLLING_NRFLAG
Signed-off-by: Xiangyou Xie xiexiangyou@huawei.com Reviewed-by: Hanjun Guo guohanjun@huawei.com Reviewed-by: zhanghailiang zhang.zhanghailiang@huawei.com Signed-off-by: Yang Yingliang yangyingliang@huawei.com --- arch/arm64/include/asm/thread_info.h | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/arch/arm64/include/asm/thread_info.h b/arch/arm64/include/asm/thread_info.h index 30c2bdea970ff..01f063a81d648 100644 --- a/arch/arm64/include/asm/thread_info.h +++ b/arch/arm64/include/asm/thread_info.h @@ -69,6 +69,7 @@ void arch_release_task_struct(struct task_struct *tsk); * TIF_NEED_RESCHED - rescheduling necessary * TIF_NOTIFY_RESUME - callback before returning to user * TIF_USEDFPU - FPU was used by this task this quantum (SMP) + * TIF_POLLING_NRFLAG - idle is polling for TIF_NEED_RESCHED */ #define TIF_SIGPENDING 0 #define TIF_NEED_RESCHED 1 @@ -82,6 +83,7 @@ void arch_release_task_struct(struct task_struct *tsk); #define TIF_SYSCALL_AUDIT 9 #define TIF_SYSCALL_TRACEPOINT 10 #define TIF_SECCOMP 11 +#define TIF_POLLING_NRFLAG 16 #define TIF_MEMDIE 18 /* is terminating due to OOM killer */ #define TIF_FREEZE 19 #define TIF_RESTORE_SIGMASK 20 @@ -108,6 +110,7 @@ void arch_release_task_struct(struct task_struct *tsk); #define _TIF_32BIT (1 << TIF_32BIT) #define _TIF_SVE (1 << TIF_SVE) #define _TIF_32BIT_AARCH64 (1 << TIF_32BIT_AARCH64) +#define _TIF_POLLING_NRFLAG (1 << TIF_POLLING_NRFLAG)
#define _TIF_WORK_MASK (_TIF_NEED_RESCHED | _TIF_SIGPENDING | \ _TIF_NOTIFY_RESUME | _TIF_FOREIGN_FPSTATE | \