--=_courier-5429-1057766435-0001-2
Content-Type: text/plain; charset=iso-8859-1
Content-Transfer-Encoding: 7bit
On Wed, 2003-07-09 at 06:49, Guillaume Chazarain wrote:
> 08/07/03 23:13:22, Davide Libenzi <davidel@xmailserver.org> wrote:
>
> >On Tue, 8 Jul 2003, Guillaume Chazarain wrote:
> >
> >> Hello,
> >>
> >> Currently the interactive points a process can have are in a [-5, 5] range,
> >> that is, 25% of the [0, 39] range. Two reasons are mentionned:
> >>
> >> 1) nice +19 interactive tasks do not preempt nice 0 CPU hogs.
> >> 2) nice -20 CPU hogs do not get preempted by nice 0 tasks.
> >>
> >> But, using 50% of the range, instead of 25% the interactivity points are better
> >> spread and both rules are still respected. Having a larger range for
> >> interactivity points it's easier to choose between two interactive tasks.
> >>
> >> So, why not changing PRIO_BONUS_RATIO to 50 instead of 25?
> >> Actually it should be in the [45, 49] range to maximize the bonus points
> >> range and satisfy both rules due to integer arithmetic.
> >
> >I believe these are the bits that broke the scheduler, that was working
> >fine during the very first shots in 2.5. IIRC Ingo was hit by ppl
> >complains about those 'nice' rules and he had to fix it. It'd be
> >interesting bring back a more generous interactive bonus and see how the
> >scheduler behave.
>
> Thanks for the info.
> Before being 25% the interactivity range was 70%, thus breaking the rules. So
> I am now more convinced that a 50% range could be a good thing.
>
Just a suggestion, why instead of changing the code you don't try the
attached patch? At least you don't have to recompile just to change a
few define's. Against 2.5.73, but applies in 2.5.74. Just the "long
sleep_time = jiffies - p->last_run;" isn't there.
I remember that I saw someone's patch nearly identical to this ( I think
it was Robert Love) but I don't remember the url.
--=_courier-5429-1057766435-0001-2
Content-Type: text/x-patch; name="patch-sched_tuning"; charset=iso-8859-1
Content-Transfer-Encoding: 7bit
Content-Disposition: attachment; filename=patch-sched_tuning
diff -Nur -X dontdiff linux-2.5.73-O1int/include/linux/sysctl.h linux-2.5.73-test/include/linux/sysctl.h
--- linux-2.5.73-O1int/include/linux/sysctl.h 2003-06-27 19:35:11.000000000 -0300
+++ linux-2.5.73-test/include/linux/sysctl.h 2003-06-27 20:45:59.000000000 -0300
@@ -130,6 +130,7 @@
KERN_PIDMAX=55, /* int: PID # limit */
KERN_CORE_PATTERN=56, /* string: pattern for core-file names */
KERN_PANIC_ON_OOPS=57, /* int: whether we will panic on an oops */
+ KERN_SCHED_TUNING=58 /* dir: scheduler tuning */
};
@@ -193,6 +194,21 @@
RANDOM_UUID=6
};
+/* /proc/sys/kernel/sched_tuning */
+enum
+{
+ SCHED_TUNING_MIN_TIMESLICE=1,
+ SCHED_TUNING_MAX_TIMESLICE=2,
+ SCHED_TUNING_BONUS_RATIO=3,
+ SCHED_TUNING_MAX_SLEEP_AVG=4,
+ SCHED_TUNING_STARVATION_LIMIT=5,
+ SCHED_TUNING_CHILD_PENALTY=6,
+ SCHED_TUNING_PARENT_PENALTY=7,
+ SCHED_TUNING_EXIT_WEIGHT=8,
+ SCHED_TUNING_INTERACTIVE_DELTA=9,
+ SCHED_TUNING_NODE_THRESHOLD=10
+};
+
/* /proc/sys/bus/isa */
enum
{
diff -Nur -X dontdiff linux-2.5.73-O1int/kernel/sched.c linux-2.5.73-test/kernel/sched.c
--- linux-2.5.73-O1int/kernel/sched.c 2003-06-27 19:57:56.000000000 -0300
+++ linux-2.5.73-test/kernel/sched.c 2003-06-27 20:45:59.000000000 -0300
@@ -65,16 +65,28 @@
* maximum timeslice is 200 msecs. Timeslices get refilled after
* they expire.
*/
-#define MIN_TIMESLICE ( 10 * HZ / 1000)
-#define MAX_TIMESLICE (200 * HZ / 1000)
-#define CHILD_PENALTY 50
-#define PARENT_PENALTY 100
-#define EXIT_WEIGHT 3
-#define PRIO_BONUS_RATIO 25
-#define INTERACTIVE_DELTA 2
-#define MAX_SLEEP_AVG (10*HZ)
-#define STARVATION_LIMIT (10*HZ)
-#define NODE_THRESHOLD 125
+int sched_min_timeslice = ( 10 * HZ / 1000);
+int sched_max_timeslice = (200 * HZ / 1000);
+int sched_prio_bonus_ratio = 25;
+int sched_max_sleep_avg = (10*HZ);
+int sched_starvation_limit = (10*HZ);
+int sched_child_penalty = 50;
+int sched_parent_penalty = 100;
+int sched_exit_weight = 3;
+int sched_interactive_delta = 2;
+int sched_node_threshold = 125;
+
+
+#define MIN_TIMESLICE sched_min_timeslice
+#define MAX_TIMESLICE sched_max_timeslice
+#define CHILD_PENALTY sched_child_penalty
+#define PARENT_PENALTY sched_parent_penalty
+#define EXIT_WEIGHT sched_exit_weight
+#define PRIO_BONUS_RATIO sched_prio_bonus_ratio
+#define INTERACTIVE_DELTA sched_interactive_delta
+#define MAX_SLEEP_AVG sched_max_sleep_avg
+#define STARVATION_LIMIT sched_starvation_limit
+#define NODE_THRESHOLD sched_node_threshold
/*
* If a task is 'interactive' then we reinsert it in the active
diff -Nur -X dontdiff linux-2.5.73-O1int/kernel/sysctl.c linux-2.5.73-test/kernel/sysctl.c
--- linux-2.5.73-O1int/kernel/sysctl.c 2003-06-27 19:38:13.000000000 -0300
+++ linux-2.5.73-test/kernel/sysctl.c 2003-06-27 20:45:59.000000000 -0300
@@ -58,6 +58,17 @@
extern int pid_max;
extern int sysctl_lower_zone_protection;
extern int min_free_kbytes;
+/* sched.c */
+extern int sched_min_timeslice;
+extern int sched_max_timeslice;
+extern int sched_prio_bonus_ratio;
+extern int sched_max_sleep_avg;
+extern int sched_starvation_limit;
+extern int sched_child_penalty;
+extern int sched_parent_penalty;
+extern int sched_exit_weight;
+extern int sched_interactive_delta;
+extern int sched_node_threshold;
/* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */
static int maxolduid = 65535;
@@ -123,6 +134,7 @@
static ctl_table debug_table[];
static ctl_table dev_table[];
extern ctl_table random_table[];
+static ctl_table sched_tuning_table[];
/* /proc declarations: */
@@ -551,6 +563,12 @@
.mode = 0644,
.proc_handler = &proc_dointvec,
},
+ {
+ .ctl_name = KERN_SCHED_TUNING,
+ .procname = "sched_tuning",
+ .mode = 0555,
+ .child = sched_tuning_table
+ },
{ .ctl_name = 0 }
};
@@ -775,6 +793,100 @@
static ctl_table dev_table[] = {
{ .ctl_name = 0 }
+};
+
+/* sched tuning */
+static ctl_table sched_tuning_table[] = {
+ /* min_timeslice */
+ {
+ .ctl_name = SCHED_TUNING_MIN_TIMESLICE,
+ .procname = "min_timeslice",
+ .mode = 0644,
+ .data = &sched_min_timeslice,
+ .maxlen = sizeof(int),
+ .proc_handler = &proc_dointvec,
+ },
+ /*max_timeslice */
+ {
+ .ctl_name = SCHED_TUNING_MAX_TIMESLICE,
+ .procname = "max_timeslice",
+ .mode = 0644,
+ .data = &sched_max_timeslice,
+ .maxlen = sizeof(int),
+ .proc_handler = &proc_dointvec,
+ },
+ /* prio_bonus_ratio */
+ {
+ .ctl_name = SCHED_TUNING_BONUS_RATIO,
+ .procname = "prio_bonus_ratio",
+ .mode = 0644,
+ .data = &sched_prio_bonus_ratio,
+ .maxlen = sizeof(int),
+ .proc_handler = &proc_dointvec,
+ },
+ /* max_sleep_avg */
+ {
+ .ctl_name = SCHED_TUNING_MAX_SLEEP_AVG,
+ .procname = "max_sleep_avg",
+ .mode = 0644,
+ .data = &sched_max_sleep_avg,
+ .maxlen = sizeof(int),
+ .proc_handler = &proc_dointvec,
+ },
+ /* starvation_limit */
+ {
+ .ctl_name = SCHED_TUNING_STARVATION_LIMIT,
+ .procname = "starvation_limit",
+ .mode = 0644,
+ .data = &sched_starvation_limit,
+ .maxlen = sizeof(int),
+ .proc_handler = &proc_dointvec,
+ },
+ /* child_penalty */
+ {
+ .ctl_name = SCHED_TUNING_CHILD_PENALTY,
+ .procname = "child_penalty",
+ .mode = 0644,
+ .data = &sched_child_penalty,
+ .maxlen = sizeof(int),
+ .proc_handler = &proc_dointvec,
+ },
+ /* parent_penalty */
+ {
+ .ctl_name = SCHED_TUNING_PARENT_PENALTY,
+ .procname = "parent_penalty",
+ .mode = 0644,
+ .data = &sched_parent_penalty,
+ .maxlen = sizeof(int),
+ .proc_handler = &proc_dointvec,
+ },
+ /* exit_weight */
+ {
+ .ctl_name = SCHED_TUNING_EXIT_WEIGHT,
+ .procname = "exit_weight",
+ .mode = 0644,
+ .data = &sched_exit_weight,
+ .maxlen = sizeof(int),
+ .proc_handler = &proc_dointvec,
+ },
+ /* interactive_delta */
+ {
+ .ctl_name = SCHED_TUNING_INTERACTIVE_DELTA,
+ .procname = "interactive_delta",
+ .mode = 0644,
+ .data = &sched_interactive_delta,
+ .maxlen = sizeof(int),
+ .proc_handler = &proc_dointvec,
+ },
+ /* node_threshold */
+ {
+ .ctl_name = SCHED_TUNING_NODE_THRESHOLD,
+ .procname = "node_threshold",
+ .mode = 0644,
+ .data = &sched_node_threshold,
+ .maxlen = sizeof(int),
+ .proc_handler = &proc_dointvec,
+ }
};
extern void init_irq_proc (void);
--=_courier-5429-1057766435-0001-2--