[committed mach 2/2] kern: avoid hardcoding the lowest priority

[Justus Winter]

The number of priorities has been changed from 32 to 50 in
6a234201081156e6d5742e7eeabb68418b518fad.

* kern/syscall_subr.c (thread_depress_priority): Avoid hardcoding the
lowest priority.
---
 kern/syscall_subr.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/kern/syscall_subr.c b/kern/syscall_subr.c
index 3c369ef..6d23462 100644
--- a/kern/syscall_subr.c
+++ b/kern/syscall_subr.c
@@ -302,8 +302,8 @@ thread_depress_priority(
  * sched_pri to their lowest possible values.
  */
 thread->depress_priority = thread->priority;
-thread->priority = 31;
-thread->sched_pri = 31;
+thread->priority = NRQS-1;
+thread->sched_pri = NRQS-1;
 if (ticks != 0)
set_timeout(&thread->depress_timer, ticks);
 
-- 
2.1.4

[committed mach 1/2] kern: disable stack allocation counters by default

[Justus Winter]

Disable the stack allocation counters by default.  Casual checking
revealed that the hits-to-miss ratio is excellent.

* kern/thread.c (stack_alloc_{hits,misses,max}): Move variables...
* kern/counters.c: ... here, and add the usual counter prefix.
* kern/counters.h: New declarations.
---
 kern/counters.c |  3 +++
 kern/counters.h |  3 +++
 kern/thread.c   | 15 +++
 3 files changed, 13 insertions(+), 8 deletions(-)

diff --git a/kern/counters.c b/kern/counters.c
index 74fd42d..0a0665b 100644
--- a/kern/counters.c
+++ b/kern/counters.c
@@ -46,6 +46,9 @@ mach_counter_t c_stacks_current = 0;
 mach_counter_t c_stacks_max = 0;
 mach_counter_t c_stacks_min = 0;
 mach_counter_t c_stacks_total = 0;
+mach_counter_t c_stack_alloc_hits = 0;
+mach_counter_t c_stack_alloc_misses = 0;
+mach_counter_t c_stack_alloc_max = 0;
 mach_counter_t c_clock_ticks = 0;
 mach_counter_t c_ipc_mqueue_send_block = 0;
 mach_counter_t c_ipc_mqueue_receive_block_user = 0;
diff --git a/kern/counters.h b/kern/counters.h
index bfa9b44..aa1e739 100644
--- a/kern/counters.h
+++ b/kern/counters.h
@@ -69,6 +69,9 @@ extern mach_counter_t c_stacks_current;
 extern mach_counter_t c_stacks_max;
 extern mach_counter_t c_stacks_min;
 extern mach_counter_t c_stacks_total;
+extern mach_counter_t c_stack_alloc_hits;
+extern mach_counter_t c_stack_alloc_misses;
+extern mach_counter_t c_stack_alloc_max;
 extern mach_counter_t c_clock_ticks;
 extern mach_counter_t c_ipc_mqueue_send_block;
 extern mach_counter_t c_ipc_mqueue_receive_block_user;
diff --git a/kern/thread.c b/kern/thread.c
index 5ffa844..009884c 100644
--- a/kern/thread.c
+++ b/kern/thread.c
@@ -124,10 +124,6 @@ vm_offset_t stack_free_list;   /* splsched 
only */
 unsigned int stack_free_count = 0; /* splsched only */
 unsigned int stack_free_limit = 1; /* patchable */
 
-unsigned int stack_alloc_hits = 0; /* debugging */
-unsigned int stack_alloc_misses = 0;   /* debugging */
-unsigned int stack_alloc_max = 0;  /* debugging */
-
 /*
  * The next field is at the base of the stack,
  * so the low end is left unsullied.
@@ -160,10 +156,10 @@ boolean_t stack_alloc_try(
 
if (stack != 0) {
stack_attach(thread, stack, resume);
-   stack_alloc_hits++;
+   counter(c_stack_alloc_hits++);
return TRUE;
} else {
-   stack_alloc_misses++;
+   counter(c_stack_alloc_misses++);
return FALSE;
}
 }
@@ -235,8 +231,11 @@ void stack_free(
stack_lock();
stack_next(stack) = stack_free_list;
stack_free_list = stack;
-   if (++stack_free_count > stack_alloc_max)
-   stack_alloc_max = stack_free_count;
+   stack_free_count += 1;
+#ifMACH_COUNTERS
+   if (stack_free_count > c_stack_alloc_max)
+   c_stack_alloc_max = stack_free_count;
+#endif /* MACH_COUNTERS */
stack_unlock();
}
 }
-- 
2.1.4