set-cpufreq-hwp allows setting the Hardware P-State (HWP) parameters.
It can be run on all or just a single cpu. There are presets of
balance, powersave & performance. Those can be further tweaked by
param:val arguments as explained in the usage description.
Parameter names are just checked to the first 3 characters to shorten
typing.
Some options are hardware dependent, and ranges can be found in
get-cpufreq-para.
Signed-off-by: Jason Andryuk <jandryuk@gmail.com>
---
tools/misc/xenpm.c | 240 +++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 240 insertions(+)
diff --git a/tools/misc/xenpm.c b/tools/misc/xenpm.c
index a686f8f46e..d3bcaf3b58 100644
--- a/tools/misc/xenpm.c
+++ b/tools/misc/xenpm.c
@@ -67,6 +67,25 @@ void show_help(void)
" set-max-cstate <num>|'unlimited' [<num2>|'unlimited']\n"
" set the C-State limitation (<num> >= 0) and\n"
" optionally the C-sub-state limitation (<num2> >= 0)\n"
+ " set-cpufreq-hwp [cpuid] [balance|performance|powersave] <param:val>*\n"
+ " set Hardware P-State (HWP) parameters\n"
+ " optionally a preset of one of\n"
+ " balance|performance|powersave\n"
+ " an optional list of param:val arguments\n"
+ " minimum:N hw_lowest ... hw_highest\n"
+ " maximum:N hw_lowest ... hw_highest\n"
+ " desired:N hw_lowest ... hw_highest\n"
+ " Set explicit performance target.\n"
+ " non-zero disables auto-HWP mode.\n"
+ " energy_perf:0-255 (or 0-15)\n"
+ " energy/performance hint\n"
+ " lower favor performance\n"
+ " higher favor powersave\n"
+ " 127 (or 7) balance\n"
+ " act_window:N{,m,u}s range 0us-1270s\n"
+ " window for internal calculations.\n"
+ " 0 lets the hardware decide.\n"
+ " get-cpufreq-para returns hw_lowest/highest.\n"
" start [seconds] start collect Cx/Px statistics,\n"
" output after CTRL-C or SIGINT or several seconds.\n"
" enable-turbo-mode [cpuid] enable Turbo Mode for processors that support it.\n"
@@ -1309,6 +1328,226 @@ void disable_turbo_mode(int argc, char *argv[])
errno, strerror(errno));
}
+/*
+ * Parse activity_window:NNN{us,ms,s} and validate range.
+ *
+ * Activity window is a 7bit mantissa (0-127) with a 3bit exponent (0-7) base
+ * 10 in microseconds. So the range is 1 microsecond to 1270 seconds. A value
+ * of 0 lets the hardware autonomously select the window.
+ *
+ * Return 0 on success
+ * -1 on error
+ * 1 Not activity_window. i.e. try parsing as another argument
+ */
+static int parse_activity_window(xc_set_hwp_para_t *set_hwp, char *p)
+{
+ char *param = NULL, *val = NULL, *suffix = NULL;
+ unsigned int u;
+ unsigned int exponent = 0;
+ unsigned int multiplier = 1;
+ int ret;
+
+ ret = sscanf(p, "%m[a-z_A-Z]:%ms", ¶m, &val);
+ if ( ret != 2 )
+ {
+ return -1;
+ }
+
+ if ( strncasecmp(param, "act", 3) != 0 )
+ {
+ ret = 1;
+
+ goto out;
+ }
+
+ free(param);
+ param = NULL;
+
+ ret = sscanf(val, "%u%ms", &u, &suffix);
+ if ( ret != 1 && ret != 2 )
+ {
+ fprintf(stderr, "invalid activity window: %s\n", val);
+
+ ret = -1;
+
+ goto out;
+ }
+
+ if ( ret == 2 && suffix )
+ {
+ if ( strcasecmp(suffix, "s") == 0 )
+ {
+ multiplier = 1000 * 1000;
+ exponent = 6;
+ }
+ else if ( strcasecmp(suffix, "ms") == 0 )
+ {
+ multiplier = 1000;
+ exponent = 3;
+ }
+ else if ( strcasecmp(suffix, "us") == 0 )
+ {
+ multiplier = 1;
+ exponent = 0;
+ }
+ else
+ {
+ fprintf(stderr, "invalid activity window units: %s\n", suffix);
+
+ ret = -1;
+ goto out;
+ }
+ }
+
+ if ( u > 1270 * 1000 * 1000 / multiplier )
+ {
+ fprintf(stderr, "activity window %s too large\n", val);
+
+ ret = -1;
+ goto out;
+ }
+
+ /* looking for 7 bits of mantissa and 3 bits of exponent */
+ while ( u > 127 )
+ {
+ u /= 10;
+ exponent += 1;
+ }
+
+ set_hwp->activity_window = ( exponent & 0x7 ) << 7 | ( u & 0x7f );
+ set_hwp->set_params |= XEN_SYSCTL_HWP_SET_ACT_WINDOW;
+
+ ret = 0;
+
+ out:
+ free(suffix);
+ free(param);
+ free(val);
+
+ return ret;
+}
+
+static int parse_hwp_opts(xc_set_hwp_para_t *set_hwp, int *cpuid,
+ int argc, char *argv[])
+{
+ int i = 0;
+
+ if ( argc < 1 )
+ return -1;
+
+ if ( parse_cpuid_non_fatal(argv[i], cpuid) == 0 )
+ {
+ i++;
+ }
+
+ if ( i == argc )
+ return -1;
+
+ if ( strcasecmp(argv[i], "powersave") == 0 )
+ {
+ set_hwp->set_params = XEN_SYSCTL_HWP_SET_PRESET_POWERSAVE;
+ i++;
+ }
+ else if ( strcasecmp(argv[i], "performance") == 0 )
+ {
+ set_hwp->set_params = XEN_SYSCTL_HWP_SET_PRESET_PERFORMANCE;
+ i++;
+ }
+ else if ( strcasecmp(argv[i], "balance") == 0 )
+ {
+ set_hwp->set_params = XEN_SYSCTL_HWP_SET_PRESET_BALANCE;
+ i++;
+ }
+
+ for ( ; i < argc; i++)
+ {
+ unsigned int val;
+ char *param;
+ int ret;
+
+ ret = parse_activity_window(set_hwp, argv[i]);
+ switch ( ret )
+ {
+ case -1:
+ return -1;
+ case 0:
+ continue;
+ break;
+ case 1:
+ /* try other parsing */
+ break;
+ }
+
+ /* sscanf can't handle split on ':' for "%ms:%u' */
+ ret = sscanf(argv[i], "%m[a-zA-Z_]:%u", ¶m, &val);
+ if ( ret != 2 )
+ {
+ fprintf(stderr, "%s is an invalid hwp parameter.\n", argv[i]);
+ return -1;
+ }
+
+ if ( val > 255 )
+ {
+ fprintf(stderr, "%s value %u is out of range.\n", param, val);
+ return -1;
+ }
+
+ if ( strncasecmp(param, "min", 3) == 0 )
+ {
+ set_hwp->minimum = val;
+ set_hwp->set_params |= XEN_SYSCTL_HWP_SET_MINIMUM;
+ }
+ else if ( strncasecmp(param, "max", 3) == 0 )
+ {
+ set_hwp->maximum = val;
+ set_hwp->set_params |= XEN_SYSCTL_HWP_SET_MAXIMUM;
+ }
+ else if ( strncasecmp(param, "des", 3) == 0 )
+ {
+ set_hwp->desired = val;
+ set_hwp->set_params |= XEN_SYSCTL_HWP_SET_DESIRED;
+ }
+ else if ( strncasecmp(param, "ene", 3) == 0 )
+ {
+ set_hwp->energy_perf = val;
+ set_hwp->set_params |= XEN_SYSCTL_HWP_SET_ENERGY_PERF;
+ }
+ else
+ {
+ fprintf(stderr, "%s is an invalid parameter\n.", param);
+ return -1;
+ }
+
+ free(param);
+ }
+
+ return 0;
+}
+
+static void hwp_set_func(int argc, char *argv[])
+{
+ xc_set_hwp_para_t set_hwp = {};
+ int cpuid = -1;
+ int i = 0;
+
+ if ( parse_hwp_opts(&set_hwp, &cpuid, argc, argv) )
+ {
+ fprintf(stderr, "Missing, excess, or invalid argument(s)\n");
+ exit(EINVAL);
+ }
+
+ if ( cpuid != -1 )
+ {
+ i = cpuid;
+ max_cpu_nr = i + 1;
+ }
+
+ for ( ; i < max_cpu_nr; i++ )
+ if ( xc_set_cpufreq_hwp(xc_handle, i, &set_hwp) )
+ fprintf(stderr, "[CPU%d] failed to set hwp params (%d - %s)\n",
+ i, errno, strerror(errno));
+}
+
struct {
const char *name;
void (*function)(int argc, char *argv[]);
@@ -1319,6 +1558,7 @@ struct {
{ "get-cpufreq-average", cpufreq_func },
{ "start", start_gather_func },
{ "get-cpufreq-para", cpufreq_para_func },
+ { "set-cpufreq-hwp", hwp_set_func },
{ "set-scaling-maxfreq", scaling_max_freq_func },
{ "set-scaling-minfreq", scaling_min_freq_func },
{ "set-scaling-governor", scaling_governor_func },
--
2.30.2
On 03.05.2021 21:28, Jason Andryuk wrote:
> @@ -1309,6 +1328,226 @@ void disable_turbo_mode(int argc, char *argv[])
> errno, strerror(errno));
> }
>
> +/*
> + * Parse activity_window:NNN{us,ms,s} and validate range.
> + *
> + * Activity window is a 7bit mantissa (0-127) with a 3bit exponent (0-7) base
> + * 10 in microseconds. So the range is 1 microsecond to 1270 seconds. A value
> + * of 0 lets the hardware autonomously select the window.
> + *
> + * Return 0 on success
> + * -1 on error
> + * 1 Not activity_window. i.e. try parsing as another argument
> + */
> +static int parse_activity_window(xc_set_hwp_para_t *set_hwp, char *p)
> +{
> + char *param = NULL, *val = NULL, *suffix = NULL;
> + unsigned int u;
> + unsigned int exponent = 0;
> + unsigned int multiplier = 1;
> + int ret;
> +
> + ret = sscanf(p, "%m[a-z_A-Z]:%ms", ¶m, &val);
I have to confess that I first needed to look up availability of the
m modifier. It looks to be in POSIX.1-2008, but not in C11 and older.
I'm therefore not sure if you can legitimately use it; I've not been
able to spot pre-existing uses throughout tools/.
Also, following the naming of other options of this tool (including
the new set-cpufreq-hwp subcommand you add here), instead of _
options should use - (and the pattern here and in the other similar
sscanf() further down then wants adjusting).
> + if ( ret != 2 )
> + {
> + return -1;
No error message at all in this case?
> + }
> +
> + if ( strncasecmp(param, "act", 3) != 0 )
> + {
> + ret = 1;
> +
> + goto out;
> + }
> +
> + free(param);
> + param = NULL;
> +
> + ret = sscanf(val, "%u%ms", &u, &suffix);
Can't you parse this right in the first sscanf()?
> + if ( ret != 1 && ret != 2 )
> + {
> + fprintf(stderr, "invalid activity window: %s\n", val);
> +
> + ret = -1;
> +
> + goto out;
> + }
> +
> + if ( ret == 2 && suffix )
The help text doesn't clarify what an omitted suffix means; it's
unambiguous only when the value is zero. (While looking at that I
also started wondering whether the range there starting at 0us is
actually appropriate - the range really starts at 1us afaict, with
0 having special meaning.)
> + {
> + if ( strcasecmp(suffix, "s") == 0 )
> + {
> + multiplier = 1000 * 1000;
> + exponent = 6;
> + }
> + else if ( strcasecmp(suffix, "ms") == 0 )
> + {
> + multiplier = 1000;
> + exponent = 3;
> + }
> + else if ( strcasecmp(suffix, "us") == 0 )
> + {
> + multiplier = 1;
> + exponent = 0;
> + }
> + else
> + {
> + fprintf(stderr, "invalid activity window units: %s\n", suffix);
I think you want to generally quote %s in such cases, to make clear
what is actually part of a malformed string.
> + ret = -1;
> + goto out;
> + }
> + }
> +
> + if ( u > 1270 * 1000 * 1000 / multiplier )
> + {
> + fprintf(stderr, "activity window %s too large\n", val);
> +
> + ret = -1;
> + goto out;
> + }
> +
> + /* looking for 7 bits of mantissa and 3 bits of exponent */
> + while ( u > 127 )
Prior to this loop, don't you need to multiply by "multiplier"?
> + {
> + u /= 10;
Fractions get silently chopped off - may want spelling out in
the help text.
> + exponent += 1;
> + }
> +
> + set_hwp->activity_window = ( exponent & 0x7 ) << 7 | ( u & 0x7f );
Excess blanks inside parentheses again.
> +static int parse_hwp_opts(xc_set_hwp_para_t *set_hwp, int *cpuid,
> + int argc, char *argv[])
> +{
> + int i = 0;
> +
> + if ( argc < 1 )
> + return -1;
> +
> + if ( parse_cpuid_non_fatal(argv[i], cpuid) == 0 )
> + {
> + i++;
> + }
Unnecessary braces again, the more that you ...
> + if ( i == argc )
> + return -1;
... don't have any here.
> + if ( strcasecmp(argv[i], "powersave") == 0 )
> + {
> + set_hwp->set_params = XEN_SYSCTL_HWP_SET_PRESET_POWERSAVE;
> + i++;
> + }
> + else if ( strcasecmp(argv[i], "performance") == 0 )
> + {
> + set_hwp->set_params = XEN_SYSCTL_HWP_SET_PRESET_PERFORMANCE;
> + i++;
> + }
> + else if ( strcasecmp(argv[i], "balance") == 0 )
> + {
> + set_hwp->set_params = XEN_SYSCTL_HWP_SET_PRESET_BALANCE;
> + i++;
> + }
> +
> + for ( ; i < argc; i++)
> + {
> + unsigned int val;
> + char *param;
> + int ret;
> +
> + ret = parse_activity_window(set_hwp, argv[i]);
> + switch ( ret )
> + {
> + case -1:
> + return -1;
> + case 0:
> + continue;
> + break;
Why "break" after "continue"? I can see compilers legitimately warning
in such a case.
> + case 1:
This may better be "default:", or could be omitted altogether. Or
alternatively you may want to have a "default:" with assert().
> + /* try other parsing */
> + break;
> + }
> +
> + /* sscanf can't handle split on ':' for "%ms:%u' */
> + ret = sscanf(argv[i], "%m[a-zA-Z_]:%u", ¶m, &val);
> + if ( ret != 2 )
> + {
> + fprintf(stderr, "%s is an invalid hwp parameter.\n", argv[i]);
Outside of this function you omit full stops from error messages.
Elsewhere in the tool full stops are also absent except in two or
three deprecation warnings. Hence I think you want to drop them
from messages in this function.
> + return -1;
> + }
> +
> + if ( val > 255 )
> + {
> + fprintf(stderr, "%s value %u is out of range.\n", param, val);
> + return -1;
> + }
> +
> + if ( strncasecmp(param, "min", 3) == 0 )
> + {
> + set_hwp->minimum = val;
> + set_hwp->set_params |= XEN_SYSCTL_HWP_SET_MINIMUM;
> + }
> + else if ( strncasecmp(param, "max", 3) == 0 )
> + {
> + set_hwp->maximum = val;
> + set_hwp->set_params |= XEN_SYSCTL_HWP_SET_MAXIMUM;
> + }
> + else if ( strncasecmp(param, "des", 3) == 0 )
> + {
> + set_hwp->desired = val;
> + set_hwp->set_params |= XEN_SYSCTL_HWP_SET_DESIRED;
> + }
> + else if ( strncasecmp(param, "ene", 3) == 0 )
> + {
> + set_hwp->energy_perf = val;
> + set_hwp->set_params |= XEN_SYSCTL_HWP_SET_ENERGY_PERF;
> + }
While I can see the point of limiting to 3 characters, you would
better not accept longer but e.g. typoed strings.
> + else
> + {
> + fprintf(stderr, "%s is an invalid parameter\n.", param);
> + return -1;
> + }
> +
> + free(param);
> + }
> +
> + return 0;
Should you perhaps return an error here if set_hwp->set_params is
still zero?
> +}
> +
> +static void hwp_set_func(int argc, char *argv[])
> +{
> + xc_set_hwp_para_t set_hwp = {};
> + int cpuid = -1;
> + int i = 0;
> +
> + if ( parse_hwp_opts(&set_hwp, &cpuid, argc, argv) )
> + {
> + fprintf(stderr, "Missing, excess, or invalid argument(s)\n");
Isn't this redundant with earlier logged messages, which are also
more specific (with the one exception noted)?
Jan
© 2016 - 2026 Red Hat, Inc.