diff -urN linux-2.5.15/include/asm-i386/bitops.h linux/include/asm-i386/bitops.h
--- linux-2.5.15/include/asm-i386/bitops.h Thu May 9 15:25:02 2002
+++ linux/include/asm-i386/bitops.h Thu May 16 17:16:51 2002
@@ -422,7 +422,7 @@
* unlikely to be set. It's guaranteed that at least one of the 140
* bits is cleared.
*/
-static inline int sched_find_first_bit(unsigned long *b)
+static inline int _sched_find_first_bit(unsigned long *b)
{
if (unlikely(b[0]))
return __ffs(b[0]);
diff -urN linux-2.5.15/include/linux/init_task.h linux/include/linux/init_task.h
--- linux-2.5.15/include/linux/init_task.h Thu May 9 15:21:53 2002
+++ linux/include/linux/init_task.h Thu May 16 17:20:08 2002
@@ -45,8 +45,8 @@
thread_info: &init_thread_info, \
flags: 0, \
lock_depth: -1, \
- prio: 120, \
- static_prio: 120, \
+ prio: MAX_PRIO-20, \
+ static_prio: MAX_PRIO-20, \
policy: SCHED_OTHER, \
cpus_allowed: -1, \
mm: NULL, \
diff -urN linux-2.5.15/include/linux/sched.h linux/include/linux/sched.h
--- linux-2.5.15/include/linux/sched.h Thu May 9 15:21:53 2002
+++ linux/include/linux/sched.h Thu May 16 17:19:22 2002
@@ -206,6 +206,50 @@
spinlock_t siglock;
};
+/*
+ * Priority of a process goes from 0..MAX_PRIO-1, valid RT
+ * priority is 0..MAX_RT_PRIO-1, and SCHED_OTHER tasks are
+ * in the range MAX_RT_PRIO..MAX_PRIO-1. Priority values
+ * are inverted: lower p->prio value means higher priority.
+ *
+ * The MAX_RT_USER_PRIO value allows the actual maximum
+ * RT priority to be separate from the value exported to
+ * user-space. This allows kernel threads to set their
+ * priority to a value higher than any user task. Note:
+ * MAX_RT_PRIO must not be smaller than MAX_USER_RT_PRIO.
+ *
+ * Both values are configurable at compile-time.
+ */
+
+#if CONFIG_MAX_USER_RT_PRIO < 100
+#define MAX_USER_RT_PRIO 100
+#elif CONFIG_MAX_USER_RT_PRIO > 1000
+#define MAX_USER_RT_PRIO 1000
+#else
+#define MAX_USER_RT_PRIO CONFIG_MAX_USER_RT_PRIO
+#endif
+
+#if CONFIG_MAX_RT_PRIO < 0
+#define MAX_RT_PRIO MAX_USER_RT_PRIO
+#elif CONFIG_MAX_RT_PRIO > 200
+#define MAX_RT_PRIO (MAX_USER_RT_PRIO + 200)
+#else
+#define MAX_RT_PRIO (MAX_USER_RT_PRIO + CONFIG_MAX_RT_PRIO)
+#endif
+
+#define MAX_PRIO (MAX_RT_PRIO + 40)
+
+/*
+ * The maximum RT priority is configurable. If the resulting
+ * bitmap is 160-bits , we can use a hand-coded routine which
+ * is optimal. Otherwise, we fall back on a generic routine for
+ * finding the first set bit from an arbitrarily-sized bitmap.
+ */
+#if MAX_PRIO < 160 && MAX_PRIO > 127
+#define sched_find_first_bit(map) _sched_find_first_bit(map)
+#else
+#define sched_find_first_bit(map) find_first_bit(map, MAX_PRIO)
+#endif
/*
* Some day this will be a full-fledged user tracking system..
diff -urN linux-2.5.15/init/Config.help linux/init/Config.help
--- linux-2.5.15/init/Config.help Thu May 9 15:21:47 2002
+++ linux/init/Config.help Thu May 16 17:23:33 2002
@@ -80,6 +80,36 @@
building a kernel for install/rescue disks or your system is very
limited in memory.
+Maximum User Real-Time Priority
+ The maximum user real-time priority. Tasks with priorities from
+ zero through one less than this value are scheduled as real-time.
+ To the application, a higher priority value implies a higher
+ priority task.
+
+ The minimum allowed value is 100 and the maximum allowed value
+ is (arbitrary) 1000. Values specified outside this range will
+ be rounded accordingly during compile-time. The default is 100.
+ Setting this higher than 100 is safe but will result in slightly
+ more processing overhead in the scheduler.
+
+ Unless you are doing specialized real-time computing and require
+ a much larger range than usual, the default is fine.
+
+Maximum Kernel Real-Time Priority
+ The difference between the maximum real-time priority and the
+ maximum user real-time priority. Usually this value is zero,
+ which sets the maximum real-time priority to the same as the
+ maximum user real-time priority. Setting this higher,
+ however, will allow kernel threads to set their priority to a
+ value higher than any user task. This is safe, but will result
+ in slightly more processing overhead in the scheduler.
+
+ This value can be at most 200. The default is zero, i.e. the
+ maximum priority and maximum user priority are the same.
+
+ Unless you are doing specialized real-time programming with
+ kernel threads, the default is fine.
+
CONFIG_MODULES
Kernel modules are small pieces of compiled code which can be
inserted in or removed from the running kernel, using the programs
diff -urN linux-2.5.15/init/Config.in linux/init/Config.in
--- linux-2.5.15/init/Config.in Thu May 9 15:21:58 2002
+++ linux/init/Config.in Thu May 16 17:22:47 2002
@@ -9,6 +9,8 @@
bool 'System V IPC' CONFIG_SYSVIPC
bool 'BSD Process Accounting' CONFIG_BSD_PROCESS_ACCT
bool 'Sysctl support' CONFIG_SYSCTL
+int 'Maximum User Real-Time Priority' CONFIG_MAX_USER_RT_PRIO 100
+int 'Maximum Kernel Real-time Priority' CONFIG_MAX_RT_PRIO 0
endmenu
mainmenu_option next_comment
diff -urN linux-2.5.15/kernel/sched.c linux/kernel/sched.c
--- linux-2.5.15/kernel/sched.c Thu May 9 15:22:53 2002
+++ linux/kernel/sched.c Thu May 16 17:15:45 2002
@@ -24,22 +24,8 @@
#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.
- *
- * MAX_USER_RT_PRIO allows the actual maximum RT priority
- * to be separate from the value exported to user-space.
- * NOTE: MAX_RT_PRIO must not be smaller than MAX_USER_RT_PRIO.
- */
-#define MAX_RT_PRIO 100
-#define MAX_USER_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)
@@ -1138,8 +1124,8 @@
}
/*
- * 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_USER_RT_PRIO, valid priority for SCHED_OTHER is 0.
*/
retval = -EINVAL;
if (lp.sched_priority < 0 || lp.sched_priority > MAX_USER_RT_PRIO-1)