On Fri, 2012-04-06 at 09:14 +0200, Juri Lelli wrote:From: Dario Faggioli<raistlin@xxxxxxxx>
It is very likely that systems that wants/needs to use the new
SCHED_DEADLINE policy also want to have the scheduling latency of
the -deadline tasks under control.
For this reason a new version of the scheduling wakeup latency,
called "wakeup_dl", is introduced.
As a consequence of applying this patch there will be three wakeup
latency tracer:
* "wakeup", that deals with all tasks in the system;
* "wakeup_rt", that deals with -rt and -deadline tasks only;
* "wakeup_dl", that deals with -deadline tasks only.
Signed-off-by: Dario Faggioli<raistlin@xxxxxxxx>
Signed-off-by: Juri Lelli<juri.lelli@xxxxxxxxx>
---
kernel/trace/trace_sched_wakeup.c | 41 ++++++++++++++++++++++++++++++++++++-
kernel/trace/trace_selftest.c | 30 ++++++++++++++++----------
2 files changed, 58 insertions(+), 13 deletions(-)
diff --git a/kernel/trace/trace_sched_wakeup.c b/kernel/trace/trace_sched_wakeup.c
index e4a70c0..9c9b1be 100644
--- a/kernel/trace/trace_sched_wakeup.c
+++ b/kernel/trace/trace_sched_wakeup.c
@@ -27,6 +27,7 @@ static int wakeup_cpu;
static int wakeup_current_cpu;
static unsigned wakeup_prio = -1;
static int wakeup_rt;
+static int wakeup_dl;
static arch_spinlock_t wakeup_lock =
(arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED;
@@ -420,6 +421,17 @@ probe_wakeup(void *ignore, struct task_struct *p, int success)
if ((wakeup_rt&& !rt_task(p)) ||
p->prio>= wakeup_prio ||
p->prio>= current->prio)
I don't think you meant to keep both if statements. Look above and
below ;-)
+ /*
+ * Semantic is like this:
+ * - wakeup tracer handles all tasks in the system, independently
+ * from their scheduling class;
+ * - wakeup_rt tracer handles tasks belonging to sched_dl and
+ * sched_rt class;
+ * - wakeup_dl handles tasks belonging to sched_dl class only.
+ */
+ if ((wakeup_dl&& !dl_task(p)) ||
+ (wakeup_rt&& !dl_task(p)&& !rt_task(p)) ||
+ (p->prio>= wakeup_prio || p->prio>= current->prio))
return;
Anyway, perhaps this should be broken up, as we don't want the double
test, that is, wakeup_rt and wakeup_dl are both checked. Perhaps do:
if (wakeup_dl&& !dl_task(p))
return;
else if (wakeup_rt&& !dl_task(p)&& !rt_task(p))
return;
if (p->prio>= wakeup_prio || p->prio>= current->prio)
return;
--
pc = preempt_count();
@@ -431,7 +443,7 @@ probe_wakeup(void *ignore, struct task_struct *p, int success)
arch_spin_lock(&wakeup_lock);
/* check for races. */
- if (!tracer_enabled || p->prio>= wakeup_prio)
+ if (!tracer_enabled || (!dl_task(p)&& p->prio>= wakeup_prio))
goto out_locked;
/* reset the trace */
@@ -539,16 +551,25 @@ static int __wakeup_tracer_init(struct trace_array *tr)