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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH] cpufreq: allow customization of some parameters
Short of having a way for powersaved to dynamically adjust these
values, at least allow specifying them on the command line. In
particular, always running at an up-threshold of 80% is perhaps nice
for laptop use, but certainly not desirable on servers. On shell
scripts invoking large numbers of short-lived processes I noticed a 50%
performance degradation on a dual-socket quad-core Barcelona just
because of the load of an individual core never crossing the 80%
boundary that would have resulted in increasing the frequency.
(Powersaved on SLE10 sets this on native kernels to 60% or 80%,
depending on whether performance or power reduction is preferred,
*divided* by the number of CPUs, but capped at the lower limit of 20%.)
Signed-off-by: Jan Beulich <jbeulich@xxxxxxxxxx>
Index: 2008-11-20/xen/common/domain.c
===================================================================
--- 2008-11-20.orig/xen/common/domain.c 2008-10-29 15:48:38.000000000 +0100
+++ 2008-11-20/xen/common/domain.c 2008-12-03 15:15:44.000000000 +0100
@@ -25,6 +25,7 @@
#include <xen/percpu.h>
#include <xen/multicall.h>
#include <xen/rcupdate.h>
+#include <acpi/cpufreq/cpufreq.h>
#include <asm/debugger.h>
#include <public/sched.h>
#include <public/vcpu.h>
@@ -41,16 +42,25 @@ boolean_param("dom0_vcpus_pin", opt_dom0
enum cpufreq_controller cpufreq_controller;
static void __init setup_cpufreq_option(char *str)
{
+ char *arg;
+
if ( !strcmp(str, "dom0-kernel") )
{
xen_processor_pmbits &= ~XEN_PROCESSOR_PM_PX;
cpufreq_controller = FREQCTL_dom0_kernel;
opt_dom0_vcpus_pin = 1;
+ return;
}
- else if ( !strcmp(str, "xen") )
+
+ if ( (arg = strpbrk(str, ",:")) != NULL )
+ *arg++ = '\0';
+
+ if ( !strcmp(str, "xen") )
{
xen_processor_pmbits |= XEN_PROCESSOR_PM_PX;
cpufreq_controller = FREQCTL_xen;
+ if ( arg && *arg )
+ cpufreq_cmdline_parse(arg);
}
}
custom_param("cpufreq", setup_cpufreq_option);
Index: 2008-11-20/xen/drivers/cpufreq/cpufreq_ondemand.c
===================================================================
--- 2008-11-20.orig/xen/drivers/cpufreq/cpufreq_ondemand.c 2008-10-01
15:37:19.000000000 +0200
+++ 2008-11-20/xen/drivers/cpufreq/cpufreq_ondemand.c 2008-12-03
15:14:53.000000000 +0100
@@ -22,15 +22,22 @@
#include <acpi/cpufreq/cpufreq.h>
#define DEF_FREQUENCY_UP_THRESHOLD (80)
+#define MIN_FREQUENCY_UP_THRESHOLD (11)
+#define MAX_FREQUENCY_UP_THRESHOLD (100)
#define MIN_DBS_INTERVAL (MICROSECS(100))
-#define MIN_SAMPLING_MILLISECS (20)
-#define MIN_STAT_SAMPLING_RATE \
+#define MIN_SAMPLING_RATE_RATIO (2)
+#define MIN_SAMPLING_MILLISECS (MIN_SAMPLING_RATE_RATIO * 10)
+#define MIN_STAT_SAMPLING_RATE \
(MIN_SAMPLING_MILLISECS * MILLISECS(1))
+#define MIN_SAMPLING_RATE \
+ (def_sampling_rate / MIN_SAMPLING_RATE_RATIO)
+#define MAX_SAMPLING_RATE (500 * def_sampling_rate)
#define DEF_SAMPLING_RATE_LATENCY_MULTIPLIER (1000)
#define TRANSITION_LATENCY_LIMIT (10 * 1000 )
static uint64_t def_sampling_rate;
+static uint64_t usr_sampling_rate;
/* Sampling types */
enum {DBS_NORMAL_SAMPLE, DBS_SUB_SAMPLE};
@@ -42,11 +49,9 @@ static unsigned int dbs_enable; /* nu
static struct dbs_tuners {
uint64_t sampling_rate;
unsigned int up_threshold;
- unsigned int ignore_nice;
unsigned int powersave_bias;
} dbs_tuners_ins = {
.up_threshold = DEF_FREQUENCY_UP_THRESHOLD,
- .ignore_nice = 0,
.powersave_bias = 0,
};
@@ -216,7 +221,20 @@ int cpufreq_governor_dbs(struct cpufreq_
if (def_sampling_rate < MIN_STAT_SAMPLING_RATE)
def_sampling_rate = MIN_STAT_SAMPLING_RATE;
- dbs_tuners_ins.sampling_rate = def_sampling_rate;
+ if (!usr_sampling_rate)
+ dbs_tuners_ins.sampling_rate = def_sampling_rate;
+ else if (usr_sampling_rate < MIN_SAMPLING_RATE) {
+ printk(KERN_WARNING "cpufreq/ondemand: "
+ "specified sampling rate too low, using %"PRIu64"\n",
+ MIN_SAMPLING_RATE);
+ dbs_tuners_ins.sampling_rate = MIN_SAMPLING_RATE;
+ } else if (usr_sampling_rate > MAX_SAMPLING_RATE) {
+ printk(KERN_WARNING "cpufreq/ondemand: "
+ "specified sampling rate too high, using %"PRIu64"\n",
+ MAX_SAMPLING_RATE);
+ dbs_tuners_ins.sampling_rate = MAX_SAMPLING_RATE;
+ } else
+ dbs_tuners_ins.sampling_rate = usr_sampling_rate;
}
dbs_timer_init(this_dbs_info);
@@ -244,3 +262,55 @@ struct cpufreq_governor cpufreq_gov_dbs
.name = "ondemand",
.governor = cpufreq_governor_dbs,
};
+
+void __init cpufreq_cmdline_parse(char *str)
+{
+ do {
+ char *val, *end = strchr(str, ',');
+
+ if ( end )
+ *end++ = '\0';
+ val = strchr(str, '=');
+ if ( val )
+ *val = '\0';
+
+ if ( !strcmp(str, "rate") && val )
+ {
+ usr_sampling_rate = simple_strtoull(val, NULL, 0);
+ }
+ else if ( !strcmp(str, "threshold") && val )
+ {
+ unsigned long tmp = simple_strtoul(val, NULL, 0);
+
+ if ( tmp < MIN_FREQUENCY_UP_THRESHOLD )
+ {
+ printk(XENLOG_WARNING "cpufreq/ondemand: "
+ "specified threshold too low, using %d\n",
+ MIN_FREQUENCY_UP_THRESHOLD);
+ tmp = MIN_FREQUENCY_UP_THRESHOLD;
+ }
+ else if ( tmp > MAX_FREQUENCY_UP_THRESHOLD )
+ {
+ printk(XENLOG_WARNING "cpufreq/ondemand: "
+ "specified threshold too high, using %d\n",
+ MAX_FREQUENCY_UP_THRESHOLD);
+ tmp = MAX_FREQUENCY_UP_THRESHOLD;
+ }
+ dbs_tuners_ins.up_threshold = tmp;
+ }
+ else if ( !strcmp(str, "bias") && val )
+ {
+ unsigned long tmp = simple_strtoul(val, NULL, 0);
+
+ if ( tmp > 1000 )
+ {
+ printk(XENLOG_WARNING "cpufreq/ondemand: "
+ "specified bias too high, using 1000\n");
+ tmp = 1000;
+ }
+ dbs_tuners_ins.powersave_bias = tmp;
+ }
+
+ str = end;
+ } while ( str );
+}
Index: 2008-11-20/xen/include/acpi/cpufreq/cpufreq.h
===================================================================
--- 2008-11-20.orig/xen/include/acpi/cpufreq/cpufreq.h 2008-10-01
15:37:19.000000000 +0200
+++ 2008-11-20/xen/include/acpi/cpufreq/cpufreq.h 2008-12-03
14:26:33.000000000 +0100
@@ -55,6 +55,8 @@ extern struct cpufreq_policy *cpufreq_cp
extern int __cpufreq_set_policy(struct cpufreq_policy *data,
struct cpufreq_policy *policy);
+void cpufreq_cmdline_parse(char *);
+
#define CPUFREQ_SHARED_TYPE_NONE (0) /* None */
#define CPUFREQ_SHARED_TYPE_HW (1) /* HW does needed coordination */
#define CPUFREQ_SHARED_TYPE_ALL (2) /* All dependent CPUs should set freq */
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