From: Jan Beulich <jbeulich@suse.com>
To: Jason Andryuk <jandryuk@gmail.com>
Cc: "Andrew Cooper" <andrew.cooper3@citrix.com>,
"Roger Pau Monné" <roger.pau@citrix.com>, "Wei Liu" <wl@xen.org>,
"George Dunlap" <george.dunlap@citrix.com>,
"Ian Jackson" <iwj@xenproject.org>,
"Julien Grall" <julien@xen.org>,
"Stefano Stabellini" <sstabellini@kernel.org>,
xen-devel@lists.xenproject.org
Subject: Re: [PATCH 06/13] cpufreq: Export HWP parameters to userspace
Date: Thu, 27 May 2021 09:55:16 +0200 [thread overview]
Message-ID: <e54c3aef-4c44-4302-f7f4-4f4733e33780@suse.com> (raw)
In-Reply-To: <20210503192810.36084-7-jandryuk@gmail.com>
On 03.05.2021 21:28, Jason Andryuk wrote:
> --- a/xen/arch/x86/acpi/cpufreq/hwp.c
> +++ b/xen/arch/x86/acpi/cpufreq/hwp.c
> @@ -523,6 +523,30 @@ static const struct cpufreq_driver __initconstrel hwp_cpufreq_driver =
> .update = hwp_cpufreq_update,
> };
>
> +int get_hwp_para(struct cpufreq_policy *policy, struct xen_hwp_para *hwp_para)
> +{
> + unsigned int cpu = policy->cpu;
> + struct hwp_drv_data *data = hwp_drv_data[cpu];
const, perhaps also for the first function parameter, and in
general (throughout the series) whenever an item is not meant to
be modified.
> + if ( data == NULL )
> + return -EINVAL;
> +
> + hwp_para->hw_feature =
> + feature_hwp_activity_window ? XEN_SYSCTL_HWP_FEAT_ACT_WINDOW : 0 |
> + feature_hwp_energy_perf ? XEN_SYSCTL_HWP_FEAT_ENERGY_PERF : 0;
This needs parentheses added, as | has higher precedence than ?:.
> --- a/xen/drivers/acpi/pmstat.c
> +++ b/xen/drivers/acpi/pmstat.c
> @@ -290,6 +290,12 @@ static int get_cpufreq_para(struct xen_sysctl_pm_op *op)
> &op->u.get_para.u.ondemand.sampling_rate,
> &op->u.get_para.u.ondemand.up_threshold);
> }
> +
> + if ( !strncasecmp(op->u.get_para.scaling_governor,
> + "hwp-internal", CPUFREQ_NAME_LEN) )
> + {
> + ret = get_hwp_para(policy, &op->u.get_para.u.hwp_para);
> + }
> op->u.get_para.turbo_enabled = cpufreq_get_turbo_status(op->cpuid);
Nit: Unnecessary parentheses again, and with the leading blank line
you also want a trailing one. (As an aside I'm also not overly happy
to see the call keyed to the governor name. Is there really no other
indication that hwp is in use?)
> --- a/xen/include/acpi/cpufreq/cpufreq.h
> +++ b/xen/include/acpi/cpufreq/cpufreq.h
> @@ -246,4 +246,7 @@ int write_userspace_scaling_setspeed(unsigned int cpu, unsigned int freq);
> void cpufreq_dbs_timer_suspend(void);
> void cpufreq_dbs_timer_resume(void);
>
> +/********************** hwp hypercall helper *************************/
> +int get_hwp_para(struct cpufreq_policy *policy, struct xen_hwp_para *hwp_para);
While I can see that the excessive number of stars matches what
we have elsewhere in the header, I still wonder if you need to go
this far for a single declaration. If you want to stick to this,
then to match the rest of the file you want to follow the comment
by a blank line.
> --- a/xen/include/public/sysctl.h
> +++ b/xen/include/public/sysctl.h
> @@ -35,7 +35,7 @@
> #include "domctl.h"
> #include "physdev.h"
>
> -#define XEN_SYSCTL_INTERFACE_VERSION 0x00000013
> +#define XEN_SYSCTL_INTERFACE_VERSION 0x00000014
As long as the size of struct xen_get_cpufreq_para doesn't change
(which from the description I imply it doesn't), you don't need to
bump the version, I don't think - your change is a pure addition
to the interface.
> @@ -301,6 +301,23 @@ struct xen_ondemand {
> uint32_t up_threshold;
> };
>
> +struct xen_hwp_para {
> + uint16_t activity_window; /* 7bit mantissa and 3bit exponent */
If you go this far with commenting, you should also make the further
aspects clear: Which bits these are, and that the exponent is taking
10 as the base (in most other cases one would expect 2).
> +#define XEN_SYSCTL_HWP_FEAT_ENERGY_PERF (1 << 0) /* energy_perf range 0-255 if
> + 1. Otherwise 0-15 */
> +#define XEN_SYSCTL_HWP_FEAT_ACT_WINDOW (1 << 1) /* activity_window supported
> + if 1 */
Style: Comment formatting. You may want to move the comment on separate
lines ahead of what they comment.
> + uint8_t hw_feature; /* bit flags for features */
> + uint8_t hw_lowest;
> + uint8_t hw_most_efficient;
> + uint8_t hw_guaranteed;
> + uint8_t hw_highest;
Any particular reason for the recurring hw_ prefixes?
Jan
next prev parent reply other threads:[~2021-05-27 8:03 UTC|newest]
Thread overview: 44+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-03 19:27 [PATCH 00/13] Intel Hardware P-States (HWP) support Jason Andryuk
2021-05-03 19:27 ` [PATCH 01/13] cpufreq: Allow restricting to internal governors only Jason Andryuk
2021-05-26 13:18 ` Jan Beulich
2021-05-26 14:12 ` Jason Andryuk
2021-05-26 15:09 ` Jan Beulich
2021-05-26 16:44 ` Jason Andryuk
2021-05-03 19:27 ` [PATCH 02/13] cpufreq: Add perf_freq to cpuinfo Jason Andryuk
2021-05-26 13:24 ` Jan Beulich
2021-05-26 14:19 ` Jason Andryuk
2021-05-03 19:28 ` [PATCH 03/13] cpufreq: Export intel_feature_detect Jason Andryuk
2021-05-26 13:27 ` Jan Beulich
2021-05-26 14:44 ` Jason Andryuk
2021-05-26 15:11 ` Jan Beulich
2021-05-03 19:28 ` [PATCH 04/13] cpufreq: Add Hardware P-State (HWP) driver Jason Andryuk
2021-05-26 14:59 ` Jan Beulich
2021-05-27 7:23 ` Jan Beulich
2021-05-27 18:50 ` Jason Andryuk
2021-05-28 6:35 ` Jan Beulich
2021-06-03 11:55 ` Jason Andryuk
2021-06-04 6:39 ` Jan Beulich
2021-05-27 7:45 ` Jan Beulich
2021-05-03 19:28 ` [PATCH 05/13] xenpm: Change get-cpufreq-para output for internal Jason Andryuk
2021-05-26 15:21 ` Jan Beulich
2021-05-27 5:54 ` Jan Beulich
2021-05-03 19:28 ` [PATCH 06/13] cpufreq: Export HWP parameters to userspace Jason Andryuk
2021-05-27 7:55 ` Jan Beulich [this message]
2021-05-28 13:19 ` Jason Andryuk
2021-05-28 13:39 ` Jan Beulich
2021-05-03 19:28 ` [PATCH 07/13] libxc: Include hwp_para in definitions Jason Andryuk
2021-05-03 19:28 ` [PATCH 08/13] xenpm: Print HWP parameters Jason Andryuk
2021-05-27 8:02 ` Jan Beulich
2021-05-03 19:28 ` [PATCH 09/13] xen: Add SET_CPUFREQ_HWP xen_sysctl_pm_op Jason Andryuk
2021-05-27 8:33 ` Jan Beulich
2021-05-03 19:28 ` [PATCH 10/13] libxc: Add xc_set_cpufreq_hwp Jason Andryuk
2021-05-04 8:03 ` Jan Beulich
2021-05-04 11:31 ` Jason Andryuk
2021-05-27 9:45 ` Jan Beulich
2021-05-03 19:28 ` [PATCH 11/13] xenpm: Factor out a non-fatal cpuid_parse variant Jason Andryuk
2021-05-27 8:41 ` Jan Beulich
2021-05-03 19:28 ` [PATCH 12/13] xenpm: Add set-cpufreq-hwp subcommand Jason Andryuk
2021-05-27 9:46 ` Jan Beulich
2021-05-03 19:28 ` [PATCH 13/13] CHANGELOG: Add Intel HWP entry Jason Andryuk
2021-05-27 9:48 ` Jan Beulich
2021-05-20 14:57 ` [PATCH 00/13] Intel Hardware P-States (HWP) support Jan Beulich
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