Add support for TIF_NOTIFY_IPI on Alpha. With TIF_NOTIFY_IPI, a sender
sending an IPI to an idle CPU in TIF_POLLING mode will set the
TIF_NOTIFY_IPI flag in the target's idle tasks's thread_info to pull the
CPU out of idle, as opposed to setting TIF_NEED_RESCHED previously. This
avoids spurious calls to schedule_idle() in cases where an IPI does not
necessarily wake up a task on the idle CPU.
Cc: Richard Henderson <richard.henderson@xxxxxxxxxx>
Cc: Ivan Kokshaysky <ink@xxxxxxxxxxxxxxxxxxxx>
Cc: Matt Turner <mattst88@xxxxxxxxx>
Cc: "Rafael J. Wysocki" <rafael@xxxxxxxxxx>
Cc: Daniel Lezcano <daniel.lezcano@xxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Juri Lelli <juri.lelli@xxxxxxxxxx>
Cc: Vincent Guittot <vincent.guittot@xxxxxxxxxx>
Cc: Dietmar Eggemann <dietmar.eggemann@xxxxxxx>
Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
Cc: Ben Segall <bsegall@xxxxxxxxxx>
Cc: Mel Gorman <mgorman@xxxxxxx>
Cc: Daniel Bristot de Oliveira <bristot@xxxxxxxxxx>
Cc: Valentin Schneider <vschneid@xxxxxxxxxx>
Cc: linux-alpha@xxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
Cc: linux-pm@xxxxxxxxxxxxxxx
Signed-off-by: K Prateek Nayak <kprateek.nayak@xxxxxxx>
---
v1..v2:
o No changes.
---
arch/alpha/include/asm/thread_info.h | 2 ++
1 file changed, 2 insertions(+)
diff --git a/arch/alpha/include/asm/thread_info.h b/arch/alpha/include/asm/thread_info.h
index 4a4d00b37986..8c17855c85c7 100644
--- a/arch/alpha/include/asm/thread_info.h
+++ b/arch/alpha/include/asm/thread_info.h
@@ -64,6 +64,7 @@ register unsigned long *current_stack_pointer __asm__ ("$30");
#define TIF_NEED_RESCHED 3 /* rescheduling necessary */
#define TIF_SYSCALL_AUDIT 4 /* syscall audit active */
#define TIF_NOTIFY_SIGNAL 5 /* signal notifications exist */
+#define TIF_NOTIFY_IPI 6 /* Pending IPI on TIF_POLLLING idle CPU */
#define TIF_DIE_IF_KERNEL 9 /* dik recursion lock */
#define TIF_MEMDIE 13 /* is terminating due to OOM killer */
#define TIF_POLLING_NRFLAG 14 /* idle is polling for TIF_NEED_RESCHED */
@@ -74,6 +75,7 @@ register unsigned long *current_stack_pointer __asm__ ("$30");
#define _TIF_NOTIFY_RESUME (1<<TIF_NOTIFY_RESUME)
#define _TIF_SYSCALL_AUDIT (1<<TIF_SYSCALL_AUDIT)
#define _TIF_NOTIFY_SIGNAL (1<<TIF_NOTIFY_SIGNAL)
+#define _TIF_NOTIFY_IPI (1<<TIF_NOTIFY_IPI)
#define _TIF_POLLING_NRFLAG (1<<TIF_POLLING_NRFLAG)
/* Work to do on interrupt/exception return. */
--
2.34.1
