@@ -83,10 +83,10 @@ DEFINE_STATIC_KEY_TRUE(sk_dynamic_irqentry_exit_cond_resched);
#define need_irq_preemption() (IS_ENABLED(CONFIG_PREEMPTION))
#endif
-static void __sched arm64_preempt_schedule_irq(void)
+static inline bool arm64_need_resched(void)
{
if (!need_irq_preemption())
- return;
+ return false;
/*
* Note: thread_info::preempt_count includes both thread_info::count
@@ -94,7 +94,7 @@ static void __sched arm64_preempt_schedule_irq(void)
* preempt_count().
*/
if (READ_ONCE(current_thread_info()->preempt_count) != 0)
- return;
+ return false;
/*
* DAIF.DA are cleared at the start of IRQ/FIQ handling, and when GIC
@@ -103,7 +103,7 @@ static void __sched arm64_preempt_schedule_irq(void)
* DAIF we must have handled an NMI, so skip preemption.
*/
if (system_uses_irq_prio_masking() && read_sysreg(daif))
- return;
+ return false;
/*
* Preempting a task from an IRQ means we leave copies of PSTATE
@@ -113,8 +113,10 @@ static void __sched arm64_preempt_schedule_irq(void)
* Only allow a task to be preempted once cpufeatures have been
* enabled.
*/
- if (system_capabilities_finalized())
- preempt_schedule_irq();
+ if (!system_capabilities_finalized())
+ return false;
+
+ return true;
}
/*
@@ -139,7 +141,8 @@ static __always_inline void __exit_to_kernel_mode(struct pt_regs *regs,
return;
}
- arm64_preempt_schedule_irq();
+ if (arm64_need_resched())
+ preempt_schedule_irq();
trace_hardirqs_on();
} else {
The generic entry do preempt_schedule_irq() by checking if need_resched() satisfied, but arm64 has some of its own additional checks such as GIC priority masking. In preparation for moving arm64 over to the generic entry code, rework arm64_preempt_schedule_irq() to check whether it need resched in a check function called arm64_need_resched(). No functional changes. Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com> --- arch/arm64/kernel/entry-common.c | 17 ++++++++++------- 1 file changed, 10 insertions(+), 7 deletions(-)