The following commit has been merged into the x86/entry branch of tip:
Commit-ID: 08f086303b4eddc61da264c2e9a8a5ee7f260604
Gitweb: https://git.kernel.org/tip/08f086303b4eddc61da264c2e9a8a5ee7f260604
Author: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
AuthorDate: Thu, 21 May 2020 22:05:25 +02:00
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitterDate: Tue, 26 May 2020 19:06:27 +02:00
x86/entry: Split out idtentry_exit_cond_resched()
The XEN PV hypercall requires the ability of conditional rescheduling when
preemption is disabled because some hypercalls take ages.
Split out the rescheduling code from idtentry_exit_cond_rcu() so it can
be reused for that.
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Acked-by: Andy Lutomirski <luto@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20200521202117.962199649@xxxxxxxxxxxxx
---
arch/x86/entry/common.c | 30 +++++++++++++++---------------
1 file changed, 15 insertions(+), 15 deletions(-)
diff --git a/arch/x86/entry/common.c b/arch/x86/entry/common.c
index 2a80e4e..066215a 100644
--- a/arch/x86/entry/common.c
+++ b/arch/x86/entry/common.c
@@ -583,6 +583,20 @@ bool noinstr idtentry_enter_cond_rcu(struct pt_regs *regs)
return false;
}
+static void idtentry_exit_cond_resched(struct pt_regs *regs, bool may_sched)
+{
+ if (may_sched && !preempt_count()) {
+ /* Sanity check RCU and thread stack */
+ rcu_irq_exit_check_preempt();
+ if (IS_ENABLED(CONFIG_DEBUG_ENTRY))
+ WARN_ON_ONCE(!on_thread_stack());
+ if (need_resched())
+ preempt_schedule_irq();
+ }
+ /* Covers both tracing and lockdep */
+ trace_hardirqs_on();
+}
+
/**
* idtentry_exit_cond_rcu - Handle return from exception with conditional RCU
* handling
@@ -624,21 +638,7 @@ void noinstr idtentry_exit_cond_rcu(struct pt_regs *regs, bool rcu_exit)
}
instrumentation_begin();
-
- /* Check kernel preemption, if enabled */
- if (IS_ENABLED(CONFIG_PREEMPTION)) {
- if (!preempt_count()) {
- /* Sanity check RCU and thread stack */
- rcu_irq_exit_check_preempt();
- if (IS_ENABLED(CONFIG_DEBUG_ENTRY))
- WARN_ON_ONCE(!on_thread_stack());
- if (need_resched())
- preempt_schedule_irq();
- }
- }
- /* Covers both tracing and lockdep */
- trace_hardirqs_on();
-
+ idtentry_exit_cond_resched(regs, IS_ENABLED(CONFIG_PREEMPTION));
instrumentation_end();
} else {
/*
|