diff mbox series

[v2,03/44] cpuidle/poll: Ensure IRQ state is invariant

Message ID 20220919101520.534233547@infradead.org
State Superseded
Headers show
Series cpuidle,rcu: Clean up the mess | expand

Commit Message

Peter Zijlstra Sept. 19, 2022, 9:59 a.m. UTC 
cpuidle_state::enter() methods should be IRQ invariant

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---
 drivers/cpuidle/poll_state.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

Comments

Frederic Weisbecker Sept. 20, 2022, 10:43 a.m. UTC | #1 
On Tue, Sep 20, 2022 at 10:57:00AM +0200, Peter Zijlstra wrote:
> On Mon, Sep 19, 2022 at 03:19:27PM +0200, Frederic Weisbecker wrote:
> > On Mon, Sep 19, 2022 at 11:59:42AM +0200, Peter Zijlstra wrote:
> > > cpuidle_state::enter() methods should be IRQ invariant
> > 
> > Got a bit confused with the invariant thing since the first chunck I
> > see in this patch is a conversion to an non-traceable local_irq_enable().
> > 
> > Maybe just add a short mention about that and why?
> 
> Changelog now reads:
> 
> ---
> Subject: cpuidle/poll: Ensure IRQ state is invariant
> From: Peter Zijlstra <peterz@infradead.org>
> Date: Tue May 31 15:43:32 CEST 2022
> 
> cpuidle_state::enter() methods should be IRQ invariant.
> 
> Additionally make sure to use raw_local_irq_*() methods since this
> cpuidle callback will be called with RCU already disabled.
> 
> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
> Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Reviewed-by: Frederic Weisbecker <frederic@kernel.org>

Thanks!
diff mbox series

Patch

--- a/drivers/cpuidle/poll_state.c
+++ b/drivers/cpuidle/poll_state.c
@@ -17,7 +17,7 @@  static int __cpuidle poll_idle(struct cp
 
 	dev->poll_time_limit = false;
 
-	local_irq_enable();
+	raw_local_irq_enable();
 	if (!current_set_polling_and_test()) {
 		unsigned int loop_count = 0;
 		u64 limit;
@@ -36,6 +36,8 @@  static int __cpuidle poll_idle(struct cp
 			}
 		}
 	}
+	raw_local_irq_disable();
+
 	current_clr_polling();
 
 	return index;