Linus,
Attached patch replaces occurrences of the magic numbers representing
maximum priority / maximum RT priority with the (already defined and
used) MAX_PRIO and MAX_RT_PRIO defines. The patch also contains some
comment additions/changes (particularly to address the double_rq_lock
ambiguity). Very simple.
This is the invariant cleanup portion of another patch I am working on:
compile-time configurable maximum RT priorities. But whether you buy
that or not, this is a sane cleanup.
Patch is against 2.5.9, super-duper-please apply. Thank you,
Robert Love
diff -urN linux-2.5.9/kernel/sched.c linux/kernel/sched.c
--- linux-2.5.9/kernel/sched.c Mon Apr 22 18:28:20 2002
+++ linux/kernel/sched.c Mon Apr 22 22:12:26 2002
@@ -24,17 +24,18 @@
#include <linux/kernel_stat.h>
/*
- * Priority of a process goes from 0 to 139. The 0-99
- * priority range is allocated to RT tasks, the 100-139
- * range is for SCHED_OTHER tasks. Priority values are
- * inverted: lower p->prio value means higher priority.
+ * Priority of a process goes from 0 to MAX_PRIO-1. The
+ * 0 to MAX_RT_PRIO-1 priority range is allocated to RT tasks,
+ * the MAX_RT_PRIO to MAX_PRIO range is for SCHED_OTHER tasks.
+ * Priority values are inverted: lower p->prio value means higher
+ * priority.
*/
#define MAX_RT_PRIO 100
#define MAX_PRIO (MAX_RT_PRIO + 40)
/*
* Convert user-nice values [ -20 ... 0 ... 19 ]
- * to static priority [ 100 ... 139 (MAX_PRIO-1) ],
+ * to static priority [ MAX_RT_PRIO..MAX_PRIO-1 ],
* and back.
*/
#define NICE_TO_PRIO(nice) (MAX_RT_PRIO + (nice) + 20)
@@ -1071,7 +1072,7 @@
*/
int task_prio(task_t *p)
{
- return p->prio - 100;
+ return p->prio - MAX_RT_PRIO;
}
int task_nice(task_t *p)
@@ -1131,13 +1132,13 @@
policy != SCHED_OTHER)
goto out_unlock;
}
-
+
/*
- * Valid priorities for SCHED_FIFO and SCHED_RR are 1..99, valid
- * priority for SCHED_OTHER is 0.
+ * Valid priorities for SCHED_FIFO and SCHED_RR are 1..MAX_RT_PRIO-1,
+ * valid priority for SCHED_OTHER is 0.
*/
retval = -EINVAL;
- if (lp.sched_priority < 0 || lp.sched_priority > 99)
+ if (lp.sched_priority < 0 || lp.sched_priority > MAX_RT_PRIO - 1)
goto out_unlock;
if ((policy == SCHED_OTHER) != (lp.sched_priority == 0))
goto out_unlock;
@@ -1157,7 +1158,7 @@
p->policy = policy;
p->rt_priority = lp.sched_priority;
if (policy != SCHED_OTHER)
- p->prio = 99 - p->rt_priority;
+ p->prio = (MAX_RT_PRIO - 1) - p->rt_priority;
else
p->prio = p->static_prio;
if (array)
@@ -1237,7 +1238,7 @@
/**
* sys_sched_setaffinity - set the cpu affinity of a process
* @pid: pid of the process
- * @len: length of the bitmask pointed to by user_mask_ptr
+ * @len: length in bytes of the bitmask pointed to by user_mask_ptr
* @user_mask_ptr: user-space pointer to the new cpu mask
*/
asmlinkage int sys_sched_setaffinity(pid_t pid, unsigned int len,
@@ -1289,7 +1290,7 @@
/**
* sys_sched_getaffinity - get the cpu affinity of a process
* @pid: pid of the process
- * @len: length of the bitmask pointed to by user_mask_ptr
+ * @len: length in bytes of the bitmask pointed to by user_mask_ptr
* @user_mask_ptr: user-space pointer to hold the current cpu mask
*/
asmlinkage int sys_sched_getaffinity(pid_t pid, unsigned int len,
@@ -1371,7 +1372,7 @@
switch (policy) {
case SCHED_FIFO:
case SCHED_RR:
- ret = 99;
+ ret = MAX_RT_PRIO - 1;
break;
case SCHED_OTHER:
ret = 0;
@@ -1511,6 +1512,12 @@
read_unlock(&tasklist_lock);
}
+/*
+ * double_rq_lock - safely lock two runqueues
+ *
+ * Note this does not disable interrupts like task_rq_lock,
+ * you need to do so manually before calling.
+ */
static inline void double_rq_lock(runqueue_t *rq1, runqueue_t *rq2)
{
if (rq1 == rq2)
@@ -1526,6 +1533,12 @@
}
}
+/*
+ * double_rq_unlock - safely unlock two runqueues
+ *
+ * Note this does not restore interrupts like task_rq_unlock,
+ * you need to do so manually after calling.
+ */
static inline void double_rq_unlock(runqueue_t *rq1, runqueue_t *rq2)
{
spin_unlock(&rq1->lock);
@@ -1675,7 +1688,7 @@
static int migration_thread(void * bind_cpu)
{
int cpu = cpu_logical_map((int) (long) bind_cpu);
- struct sched_param param = { sched_priority: 99 };
+ struct sched_param param = { sched_priority: MAX_RT_PRIO - 1 };
runqueue_t *rq;
int ret;
-
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This archive was generated by hypermail 2b29 : Tue Apr 23 2002 - 22:00:34 EST