bin/115513: [PATCH] Add step down/up options to powerd(8)

[Oliver Fromme]

>Number:         115513
>Category:       bin
>Synopsis:       [PATCH] Add step down/up options to powerd(8)
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          change-request
>Submitter-Id:   current-users
>Arrival-Date:   Tue Aug 14 11:40:02 GMT 2007
>Closed-Date:
>Last-Modified:
>Originator:     Oliver Fromme
>Release:        FreeBSD 6.2-STABLE-20070808 i386
>Organization:
secnetix GmbH & Co. KG
		http://www.secnetix.de/bsd
>Environment:
System: FreeBSD pluto.secnetix.de 6.2-STABLE-20070808 FreeBSD 6.2-STABLE-20070808 #0: Wed Aug 8 14:35:59 CEST 2007 olli at pluto.secnetix.de:/usr/obj/usr/src/sys/PLUTO i386

>Description:

   By default, powerd(1) adjusts the CPU freq level by one
   step down upon every polling interval if the CPU idle
   percent level is considered to be high, or two steps up
   if the CPU idle percent level is considered to be low.
   Those values (one step down, two steps up) are hardcoded
   and cannot be changed by the user.

   However, in some situations it is desirable to change
   those numbers.  In particular, if the system supports
   many fine-grained levels, it can take a long time for
   the CPU to get back to full performance.  Making the
   polling interval shorter isn't always a desirable
   solution because of side effects.

   The patch presented here adds two options -d and -u
   which specify the number of freq steps (down and up,
   respectively) when changing the performance level.
   The default values are 1 and 2, i.e. the same as
   previous behaviour without the patch.

   A diff to the manpage is included, too.

>How-To-Repeat:

   n/a

>Fix:

--- powerd.8.orig	2006-01-24 18:02:39.000000000 +0100
+++ powerd.8	2007-08-14 12:51:33.000000000 +0200
@@ -34,11 +34,13 @@
 .Nm
 .Op Fl a Ar mode
 .Op Fl b Ar mode
+.Op Fl d Ar steps_down
 .Op Fl i Ar percent
 .Op Fl n Ar mode
 .Op Fl p Ar ival
 .Op Fl P Ar pidfile
 .Op Fl r Ar percent
+.Op Fl u Ar steps_up
 .Op Fl v
 .Sh DESCRIPTION
 The
@@ -70,6 +72,11 @@
 Selects the
 .Ar mode
 to use while on battery power.
+.It Fl d Ar steps_down
+In adaptive mode, degrade the performance by
+.Ar steps_down
+levels every time the CPU idle percent level is considered to be high.
+The default is 1.
 .It Fl i Ar percent
 Specifies the CPU idle percent level when
 adaptive
@@ -92,6 +99,11 @@
 adaptive
 mode should consider the CPU running and increase performance.
 The default is 65% or lower.
+.It Fl u Ar steps_up
+In adaptive mode, increase the performance by
+.Ar steps_up
+levels every time the CPU idle percent level is considered to be low.
+The default is 2.
 .It Fl v
 Verbose mode.
 Messages about power changes will be printed to stdout and
--- powerd.c.orig	2007-08-08 13:52:24.000000000 +0200
+++ powerd.c	2007-08-14 12:43:37.000000000 +0200
@@ -50,6 +50,8 @@
 #define DEFAULT_ACTIVE_PERCENT	65
 #define DEFAULT_IDLE_PERCENT	90
 #define DEFAULT_POLL_INTERVAL	500	/* Poll interval in milliseconds */
+#define DEFAULT_STEPS_DOWN	1
+#define DEFAULT_STEPS_UP	2
 
 enum modes_t {
 	MODE_MIN,
@@ -261,6 +263,7 @@
 	long idle, total;
 	int curfreq, *freqs, i, *mwatts, numfreqs;
 	int ch, mode_ac, mode_battery, mode_none, acline, mode, vflag;
+	int steps_down, steps_up;
 	uint64_t mjoules_used;
 	size_t len;
 
@@ -269,6 +272,8 @@
 	cpu_running_mark = DEFAULT_ACTIVE_PERCENT;
 	cpu_idle_mark = DEFAULT_IDLE_PERCENT;
 	poll_ival = DEFAULT_POLL_INTERVAL;
+	steps_down = DEFAULT_STEPS_DOWN;
+	steps_up = DEFAULT_STEPS_UP;
 	mjoules_used = 0;
 	vflag = 0;
 	apm_fd = -1;
@@ -277,7 +282,7 @@
 	if (geteuid() != 0)
 		errx(1, "must be root to run");
 
-	while ((ch = getopt(argc, argv, "a:b:i:n:p:P:r:v")) != EOF)
+	while ((ch = getopt(argc, argv, "a:b:d:i:n:p:P:r:u:v")) != EOF)
 		switch (ch) {
 		case 'a':
 			parse_mode(optarg, &mode_ac, ch);
@@ -285,6 +290,14 @@
 		case 'b':
 			parse_mode(optarg, &mode_battery, ch);
 			break;
+		case 'd':
+			steps_down = atoi(optarg);
+			if (steps_down < 0) {
+				warnx("%d is not a valid step count",
+				    steps_down);
+				usage();
+			}
+			break;
 		case 'i':
 			cpu_idle_mark = atoi(optarg);
 			if (cpu_idle_mark < 0 || cpu_idle_mark > 100) {
@@ -314,6 +327,14 @@
 				usage();
 			}
 			break;
+		case 'u':
+			steps_up = atoi(optarg);
+			if (steps_up < 0) {
+				warnx("%d is not a valid step count",
+				    steps_up);
+				usage();
+			}
+			break;
 		case 'v':
 			vflag = 1;
 			break;
@@ -470,7 +491,7 @@
 		}
 		if (idle < (total * cpu_running_mark) / 100 &&
 		    curfreq < freqs[0]) {
-			i -= 2;
+			i -= steps_down;
 			if (i < 0)
 				i = 0;
 			if (vflag) {
@@ -483,7 +504,9 @@
 				    freqs[i]);
 		} else if (idle > (total * cpu_idle_mark) / 100 &&
 		    curfreq > freqs[numfreqs - 1]) {
-			i++;
+			i += steps_up;
+			if (i > numfreqs - 1)
+				i = numfreqs - 1;
 			if (vflag) {
 				printf("idle time > %d%%, decreasing clock"
 				    " speed from %d MHz to %d MHz\n",
>Release-Note:
>Audit-Trail:
>Unformatted: