[patch 9/9] Scheduler profiling - Use conditional calls

Mathieu Desnoyers
2007-05-29T18:40:00Z

[-- Attachment #1: profiling-use-cond-calls.patch --]
[-- Type: text/plain, Size: 3195 bytes --]

Use conditional calls with lower d-cache hit in optimized version as a
condition for scheduler profiling call.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>

---
kernel/profile.c | 4 ++++
kernel/sched.c | 32 +++++++++++++++++++-------------
2 files changed, 23 insertions(+), 13 deletions(-)

Index: linux-2.6-lttng/kernel/profile.c
===================================================================
--- linux-2.6-lttng.orig/kernel/profile.c 2007-05-29 11:33:11.000000000 -0400
+++ linux-2.6-lttng/kernel/profile.c 2007-05-29 11:37:46.000000000 -0400
@@ -23,6 +23,7 @@
#include <linux/profile.h>
#include <linux/highmem.h>
#include <linux/mutex.h>
+#include <linux/condcall.h>
#include <asm/sections.h>
#include <asm/semaphore.h>
#include <asm/irq_regs.h>
@@ -91,6 +92,8 @@
printk(KERN_INFO "kernel profiling enabled (shift: %ld)\n",
prof_shift);
}
+ if (prof_on)
+ BUG_ON(cond_call_arm("profile_on"));
return 1;
}
__setup("profile=", profile_setup);
@@ -555,6 +558,7 @@
return 0;
out_cleanup:
prof_on = 0;
+ cond_call_disarm("profile_on");
smp_mb();
on_each_cpu(profile_nop, NULL, 0, 1);
for_each_online_cpu(cpu) {
Index: linux-2.6-lttng/kernel/sched.c
===================================================================
--- linux-2.6-lttng.orig/kernel/sched.c 2007-05-29 11:38:06.000000000 -0400
+++ linux-2.6-lttng/kernel/sched.c 2007-05-29 11:42:36.000000000 -0400
@@ -54,6 +54,7 @@
#include <linux/kprobes.h>
#include <linux/delayacct.h>
#include <linux/reciprocal_div.h>
+#include <linux/condcall.h>

#include <asm/tlb.h>
#include <asm/unistd.h>
@@ -972,6 +973,21 @@
}

/*
+ * Sleep time is in units of nanosecs, so shift by 20 to get a
+ * milliseconds-range estimation of the amount of time that the task
+ * spent sleeping:
+ */
+static inline void activate_task_prof(struct task_struct *p,
+ unsigned long long now)
+{
+ if (unlikely(prof_on == SLEEP_PROFILING)) {
+ if (p->state == TASK_UNINTERRUPTIBLE)
+ profile_hits(SLEEP_PROFILING, (void *)get_wchan(p),
+ (now - p->timestamp) >> 20);
+ }
+}
+
+/*
* activate_task - move a task to the runqueue and do priority recalculation
*
* Update all the scheduling statistics stuff. (sleep average
@@ -993,18 +1009,7 @@
+ rq->most_recent_timestamp;
}
#endif
-
- /*
- * Sleep time is in units of nanosecs, so shift by 20 to get a
- * milliseconds-range estimation of the amount of time that the task
- * spent sleeping:
- */
- if (unlikely(prof_on == SLEEP_PROFILING)) {
- if (p->state == TASK_UNINTERRUPTIBLE)
- profile_hits(SLEEP_PROFILING, (void *)get_wchan(p),
- (now - p->timestamp) >> 20);
- }
-
+ cond_call(profile_on, activate_task_prof(p, now));
p->prio = recalc_task_prio(p, now);

/*
@@ -3534,7 +3539,8 @@
print_irqtrace_events(current);
dump_stack();
}
- profile_hit(SCHED_PROFILING, __builtin_return_address(0));
+ cond_call(profile_on,
+ profile_hit(SCHED_PROFILING, __builtin_return_address(0)));

need_resched:
preempt_disable();