[Xenomai-git] Jan Kiszka : nucleus: Use direct gatekeeper wakeup instead of a waitqueue
Module: xenomai-head
Branch: master
Commit: 2178c7822c2a01abaa739ab80d0ad5e98b9d648a
URL:
http://git.xenomai.org/?p=xenomai-head.git;a=commit;h=2178c7822c2a01abaa739ab80d0ad5e98b9d648a
Author: Jan Kiszka jan.kis...@siemens.com
Date: Mon Jul 18 13:57:27 2011 +0200
nucleus: Use direct gatekeeper wakeup instead of a waitqueue
By switching to wake_up_process, we can issue the gatekeeper wakeup
directly from xnshadow_harden, also under PREEMPT-RT. We just need to
ensure that TASK_INTERRUPTIBLE is set before the gksync is signaled so
that we do not miss a wakeup.
Signed-off-by: Jan Kiszka jan.kis...@siemens.com
---
include/nucleus/sched.h |1 -
ksrc/nucleus/shadow.c | 42 +-
2 files changed, 5 insertions(+), 38 deletions(-)
diff --git a/include/nucleus/sched.h b/include/nucleus/sched.h
index e251329..df8853b 100644
--- a/include/nucleus/sched.h
+++ b/include/nucleus/sched.h
@@ -111,7 +111,6 @@ typedef struct xnsched {
#ifdef CONFIG_XENO_OPT_PERVASIVE
struct task_struct *gatekeeper;
- wait_queue_head_t gkwaitq;
struct semaphore gksync;
struct xnthread *gktarget;
#endif
diff --git a/ksrc/nucleus/shadow.c b/ksrc/nucleus/shadow.c
index a9d21b0..eea9151 100644
--- a/ksrc/nucleus/shadow.c
+++ b/ksrc/nucleus/shadow.c
@@ -91,7 +91,6 @@ static struct __lostagerq {
#define LO_SIGGRP_REQ 2
#define LO_SIGTHR_REQ 3
#define LO_UNMAP_REQ 4
-#define LO_GKWAKE_REQ 5
int type;
struct task_struct *task;
int arg;
@@ -758,9 +757,6 @@ static void lostage_handler(void *cookie)
int cpu, reqnum, type, arg, sig, sigarg;
struct __lostagerq *rq;
struct task_struct *p;
-#ifdef CONFIG_PREEMPT_RT
- struct xnsched *sched;
-#endif
cpu = smp_processor_id();
rq = lostagerq[cpu];
@@ -818,13 +814,6 @@ static void lostage_handler(void *cookie)
case LO_SIGGRP_REQ:
kill_proc(p-pid, arg, 1);
break;
-
-#ifdef CONFIG_PREEMPT_RT
- case LO_GKWAKE_REQ:
- sched = xnpod_sched_slot(cpu);
- wake_up_interruptible_sync(sched-gkwaitq);
- break;
-#endif
}
}
}
@@ -866,7 +855,6 @@ static inline int normalize_priority(int prio)
static int gatekeeper_thread(void *data)
{
struct task_struct *this_task = current;
- DECLARE_WAITQUEUE(wait, this_task);
int cpu = (long)data;
struct xnsched *sched = xnpod_sched_slot(cpu);
struct xnthread *target;
@@ -879,12 +867,10 @@ static int gatekeeper_thread(void *data)
set_cpus_allowed(this_task, cpumask);
set_linux_task_priority(this_task, MAX_RT_PRIO - 1);
- init_waitqueue_head(sched-gkwaitq);
- add_wait_queue_exclusive(sched-gkwaitq, wait);
+ set_current_state(TASK_INTERRUPTIBLE);
up(sched-gksync); /* Sync with xnshadow_mount(). */
for (;;) {
- set_current_state(TASK_INTERRUPTIBLE);
up(sched-gksync); /* Make the request token available. */
schedule();
@@ -923,6 +909,7 @@ static int gatekeeper_thread(void *data)
xnlock_put_irqrestore(nklock, s);
xnpod_schedule();
}
+ set_current_state(TASK_INTERRUPTIBLE);
}
return 0;
@@ -1001,23 +988,9 @@ redo:
sched-gktarget = thread;
xnthread_set_info(thread, XNATOMIC);
set_current_state(TASK_INTERRUPTIBLE | TASK_ATOMICSWITCH);
-#ifndef CONFIG_PREEMPT_RT
- /*
-* We may not hold the preemption lock across calls to
-* wake_up_*() services over fully preemptible kernels, since
-* tasks might sleep when contending for spinlocks. The wake
-* up call for the gatekeeper will happen later, over an APC
-* we kick in do_schedule_event() on the way out for the
-* hardening task.
-*
-* We could delay the wake up call over non-RT 2.6 kernels as
-* well, but not when running over 2.4 (scheduler innards
-* would not allow this, causing weirdnesses when hardening
-* tasks). So we always do the early wake up when running
-* non-RT, which includes 2.4.
-*/
- wake_up_interruptible_sync(sched-gkwaitq);
-#endif
+
+ wake_up_process(sched-gatekeeper);
+
schedule();
xnthread_clear_info(thread, XNATOMIC);
@@ -2559,11 +2532,6 @@ static inline void do_schedule_event(struct task_struct
*next_task)
prev_task = current;
prev = xnshadow_thread(prev_task);
-#ifdef CONFIG_PREEMPT_RT
- if (prev xnthread_test_info(prev, XNATOMIC))
- schedule_linux_call(LO_GKWAKE_REQ, prev_task, 0);
-#endif
-
next = xnshadow_thread(next_task);
set_switch_lock_owner(prev_task);
___
[Xenomai-git] Jan Kiszka : nucleus: Use direct gatekeeper wakeup instead of a waitqueue
Module: xenomai-jki
Branch: for-upstream
Commit: 2178c7822c2a01abaa739ab80d0ad5e98b9d648a
URL:
http://git.xenomai.org/?p=xenomai-jki.git;a=commit;h=2178c7822c2a01abaa739ab80d0ad5e98b9d648a
Author: Jan Kiszka jan.kis...@siemens.com
Date: Mon Jul 18 13:57:27 2011 +0200
nucleus: Use direct gatekeeper wakeup instead of a waitqueue
By switching to wake_up_process, we can issue the gatekeeper wakeup
directly from xnshadow_harden, also under PREEMPT-RT. We just need to
ensure that TASK_INTERRUPTIBLE is set before the gksync is signaled so
that we do not miss a wakeup.
Signed-off-by: Jan Kiszka jan.kis...@siemens.com
---
include/nucleus/sched.h |1 -
ksrc/nucleus/shadow.c | 42 +-
2 files changed, 5 insertions(+), 38 deletions(-)
diff --git a/include/nucleus/sched.h b/include/nucleus/sched.h
index e251329..df8853b 100644
--- a/include/nucleus/sched.h
+++ b/include/nucleus/sched.h
@@ -111,7 +111,6 @@ typedef struct xnsched {
#ifdef CONFIG_XENO_OPT_PERVASIVE
struct task_struct *gatekeeper;
- wait_queue_head_t gkwaitq;
struct semaphore gksync;
struct xnthread *gktarget;
#endif
diff --git a/ksrc/nucleus/shadow.c b/ksrc/nucleus/shadow.c
index a9d21b0..eea9151 100644
--- a/ksrc/nucleus/shadow.c
+++ b/ksrc/nucleus/shadow.c
@@ -91,7 +91,6 @@ static struct __lostagerq {
#define LO_SIGGRP_REQ 2
#define LO_SIGTHR_REQ 3
#define LO_UNMAP_REQ 4
-#define LO_GKWAKE_REQ 5
int type;
struct task_struct *task;
int arg;
@@ -758,9 +757,6 @@ static void lostage_handler(void *cookie)
int cpu, reqnum, type, arg, sig, sigarg;
struct __lostagerq *rq;
struct task_struct *p;
-#ifdef CONFIG_PREEMPT_RT
- struct xnsched *sched;
-#endif
cpu = smp_processor_id();
rq = lostagerq[cpu];
@@ -818,13 +814,6 @@ static void lostage_handler(void *cookie)
case LO_SIGGRP_REQ:
kill_proc(p-pid, arg, 1);
break;
-
-#ifdef CONFIG_PREEMPT_RT
- case LO_GKWAKE_REQ:
- sched = xnpod_sched_slot(cpu);
- wake_up_interruptible_sync(sched-gkwaitq);
- break;
-#endif
}
}
}
@@ -866,7 +855,6 @@ static inline int normalize_priority(int prio)
static int gatekeeper_thread(void *data)
{
struct task_struct *this_task = current;
- DECLARE_WAITQUEUE(wait, this_task);
int cpu = (long)data;
struct xnsched *sched = xnpod_sched_slot(cpu);
struct xnthread *target;
@@ -879,12 +867,10 @@ static int gatekeeper_thread(void *data)
set_cpus_allowed(this_task, cpumask);
set_linux_task_priority(this_task, MAX_RT_PRIO - 1);
- init_waitqueue_head(sched-gkwaitq);
- add_wait_queue_exclusive(sched-gkwaitq, wait);
+ set_current_state(TASK_INTERRUPTIBLE);
up(sched-gksync); /* Sync with xnshadow_mount(). */
for (;;) {
- set_current_state(TASK_INTERRUPTIBLE);
up(sched-gksync); /* Make the request token available. */
schedule();
@@ -923,6 +909,7 @@ static int gatekeeper_thread(void *data)
xnlock_put_irqrestore(nklock, s);
xnpod_schedule();
}
+ set_current_state(TASK_INTERRUPTIBLE);
}
return 0;
@@ -1001,23 +988,9 @@ redo:
sched-gktarget = thread;
xnthread_set_info(thread, XNATOMIC);
set_current_state(TASK_INTERRUPTIBLE | TASK_ATOMICSWITCH);
-#ifndef CONFIG_PREEMPT_RT
- /*
-* We may not hold the preemption lock across calls to
-* wake_up_*() services over fully preemptible kernels, since
-* tasks might sleep when contending for spinlocks. The wake
-* up call for the gatekeeper will happen later, over an APC
-* we kick in do_schedule_event() on the way out for the
-* hardening task.
-*
-* We could delay the wake up call over non-RT 2.6 kernels as
-* well, but not when running over 2.4 (scheduler innards
-* would not allow this, causing weirdnesses when hardening
-* tasks). So we always do the early wake up when running
-* non-RT, which includes 2.4.
-*/
- wake_up_interruptible_sync(sched-gkwaitq);
-#endif
+
+ wake_up_process(sched-gatekeeper);
+
schedule();
xnthread_clear_info(thread, XNATOMIC);
@@ -2559,11 +2532,6 @@ static inline void do_schedule_event(struct task_struct
*next_task)
prev_task = current;
prev = xnshadow_thread(prev_task);
-#ifdef CONFIG_PREEMPT_RT
- if (prev xnthread_test_info(prev, XNATOMIC))
- schedule_linux_call(LO_GKWAKE_REQ, prev_task, 0);
-#endif
-
next = xnshadow_thread(next_task);
set_switch_lock_owner(prev_task);
___
