Commit-ID:  0cc5281aa592d0020868f6ccaed359b4ad7b2684
Gitweb:     http://git.kernel.org/tip/0cc5281aa592d0020868f6ccaed359b4ad7b2684
Author:     Thomas Gleixner <[email protected]>
AuthorDate: Tue, 7 Jul 2015 16:45:15 +0200
Committer:  Thomas Gleixner <[email protected]>
CommitDate: Tue, 7 Jul 2015 18:46:48 +0200

tick/broadcast: Return busy when IPI is pending

Tell the idle code not to go deep if the broadcast IPI is about to
arrive.

[ Split out from a larger combo patch ]

Tested-by: Sudeep Holla <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Cc: Suzuki Poulose <[email protected]>
Cc: Lorenzo Pieralisi <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Rafael J. Wysocki <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Preeti U Murthy <[email protected]>
Cc: Ingo Molnar <[email protected]>
Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1507070929360.3916@nanos
---
 kernel/time/tick-broadcast.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/kernel/time/tick-broadcast.c b/kernel/time/tick-broadcast.c
index da7b40f..70b47bc 100644
--- a/kernel/time/tick-broadcast.c
+++ b/kernel/time/tick-broadcast.c
@@ -725,11 +725,15 @@ int __tick_broadcast_oneshot_control(enum 
tick_broadcast_state state)
                         * if the cpu local event is earlier than the
                         * broadcast event. If the current CPU is in
                         * the force mask, then we are going to be
-                        * woken by the IPI right away.
+                        * woken by the IPI right away; we return
+                        * busy, so the CPU does not try to go deep
+                        * idle.
                         */
-                       if (!cpumask_test_cpu(cpu, tick_broadcast_force_mask) &&
-                           dev->next_event.tv64 < bc->next_event.tv64)
+                       if (cpumask_test_cpu(cpu, tick_broadcast_force_mask)) {
+                               ret = -EBUSY;
+                       } else if (dev->next_event.tv64 < bc->next_event.tv64) {
                                tick_broadcast_set_event(bc, cpu, 
dev->next_event);
+                       }
                }
                /*
                 * If the current CPU owns the hrtimer broadcast
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Reply via email to