Add enum umcg_kick_flags:
@UMCG_KICK_RESCHED: reschedule the task; used for worker preemption
@UMCG_KICK_TTWU: wake the task; used to wake servers.
It is sometimes useful to wake UMCG servers from the userspace, for
example when a server detects a worker wakeup and wakes an idle server to
run the newly woken worker.
Signed-off-by: Peter Oskolkov <posk@xxxxxxxxxx>
---
include/uapi/linux/umcg.h | 10 ++++++++++
kernel/sched/umcg.c | 7 +++++--
2 files changed, 15 insertions(+), 2 deletions(-)
diff --git a/include/uapi/linux/umcg.h b/include/uapi/linux/umcg.h
index 93fccb44283b..a29e5e91a251 100644
--- a/include/uapi/linux/umcg.h
+++ b/include/uapi/linux/umcg.h
@@ -148,4 +148,14 @@ enum umcg_ctl_flag {
UMCG_CTL_WORKER = 0x10000,
};
+/**
+ * enum umcg_kick_flag - flags to pass to sys_umcg_kick
+ * @UMCG_KICK_RESCHED: reschedule the task; used for worker preemption
+ * @UMCG_KICK_TTWU: wake the task; used to wake servers
+ */
+enum umcg_kick_flag {
+ UMCG_KICK_RESCHED = 0x001,
+ UMCG_KICK_TTWU = 0x002,
+};
+
#endif /* _UAPI_LINUX_UMCG_H */
diff --git a/kernel/sched/umcg.c b/kernel/sched/umcg.c
index b85dec6b82e4..e33ec9eddc3e 100644
--- a/kernel/sched/umcg.c
+++ b/kernel/sched/umcg.c
@@ -669,12 +669,15 @@ SYSCALL_DEFINE2(umcg_kick, u32, flags, pid_t, tid)
if (!task)
return -ESRCH;
- if (flags)
+ if (flags != UMCG_KICK_RESCHED && flags != UMCG_KICK_TTWU)
return -EINVAL;
#ifdef CONFIG_SMP
- smp_send_reschedule(task_cpu(task));
+ if (flags == UMCG_KICK_RESCHED)
+ smp_send_reschedule(task_cpu(task));
#endif
+ if (flags == UMCG_KICK_TTWU)
+ try_to_wake_up(task, TASK_NORMAL, 0);
return 0;
}
--
2.34.1.703.g22d0c6ccf7-goog
