From 51443fbf3d2cde16011b994252c8004ebcd66fb0 Mon Sep 17 00:00:00 2001 From: Prarit Bhargava Date: Thu, 15 Oct 2015 07:34:15 -0400 Subject: [PATCH] cpufreq: intel_pstate: Fix intel_pstate powersave min_perf_pct value On systems that initialize the intel_pstate driver with the performance governor, and then switch to the powersave governor will not transition to lower cpu frequencies until /sys/devices/system/cpu/intel_pstate/min_perf_pct is set to a low value. The behavior of governor switching changed after commit a04759924e25 ("[cpufreq] intel_pstate: honor user space min_perf_pct override on resume"). The commit introduced tracking of performance percentage changes via sysfs in order to restore userspace changes during suspend/resume. The problem occurs because the global values of the newly introduced max_sysfs_pct and min_sysfs_pct are not lowered on the governor change and this causes the powersave governor to inherit the performance governor's settings. A simple change would have been to reset max_sysfs_pct to 100 and min_sysfs_pct to 0 on a governor change, which fixes the problem with governor switching. However, since we cannot break userspace[1] the fix is now to give each governor its own limits storage area so that governor specific changes are tracked. I successfully tested this by booting with both the performance governor and the powersave governor by default, and switching between the two governors (while monitoring /sys/devices/system/cpu/intel_pstate/ values, and looking at the output of cpupower frequency-info). Suspend/Resume testing was performed by Doug Smythies. [1] Systems which suspend/resume using the unmaintained pm-utils package will always transition to the performance governor before the suspend and after the resume. This means a system using the powersave governor will go from powersave to performance, then suspend/resume, performance to powersave. The simple change during governor changes would have been overwritten when the governor changed before and after the suspend/resume. I have submitted https://bugzilla.redhat.com/show_bug.cgi?id=1271225 against Fedora to remove the 94cpufreq file that causes the problem. It should be noted that pm-utils is obsoleted with newer versions of systemd. Signed-off-by: Prarit Bhargava Acked-by: Kristen Carlson Accardi Signed-off-by: Rafael J. Wysocki --- drivers/cpufreq/intel_pstate.c | 142 ++++++++++++++++++++------------- 1 file changed, 85 insertions(+), 57 deletions(-) diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c index 6a5a22192128..93a3c635ea27 100644 --- a/drivers/cpufreq/intel_pstate.c +++ b/drivers/cpufreq/intel_pstate.c @@ -167,7 +167,20 @@ struct perf_limits { int min_perf_ctl; }; -static struct perf_limits limits = { +static struct perf_limits performance_limits = { + .no_turbo = 0, + .turbo_disabled = 0, + .max_perf_pct = 100, + .max_perf = int_tofp(1), + .min_perf_pct = 100, + .min_perf = int_tofp(1), + .max_policy_pct = 100, + .max_sysfs_pct = 100, + .min_policy_pct = 0, + .min_sysfs_pct = 0, +}; + +static struct perf_limits powersave_limits = { .no_turbo = 0, .turbo_disabled = 0, .max_perf_pct = 100, @@ -182,6 +195,12 @@ static struct perf_limits limits = { .min_perf_ctl = 0, }; +#ifdef CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE +static struct perf_limits *limits = &performance_limits; +#else +static struct perf_limits *limits = &powersave_limits; +#endif + #if IS_ENABLED(CONFIG_ACPI) /* * The max target pstate ratio is a 8 bit value in both PLATFORM_INFO MSR and @@ -256,7 +275,7 @@ static int intel_pstate_init_perf_limits(struct cpufreq_policy *policy) if (turbo_pss_ctl <= cpu->pstate.max_pstate && turbo_pss_ctl > cpu->pstate.min_pstate) { pr_debug("intel_pstate: no turbo range exists in _PSS\n"); - limits.no_turbo = limits.turbo_disabled = 1; + limits->no_turbo = limits->turbo_disabled = 1; cpu->pstate.turbo_pstate = cpu->pstate.max_pstate; turbo_absent = true; } @@ -415,7 +434,7 @@ static inline void update_turbo_state(void) cpu = all_cpu_data[0]; rdmsrl(MSR_IA32_MISC_ENABLE, misc_en); - limits.turbo_disabled = + limits->turbo_disabled = (misc_en & MSR_IA32_MISC_ENABLE_TURBO_DISABLE || cpu->pstate.max_pstate == cpu->pstate.turbo_pstate); } @@ -434,14 +453,14 @@ static void intel_pstate_hwp_set(void) for_each_online_cpu(cpu) { rdmsrl_on_cpu(cpu, MSR_HWP_REQUEST, &value); - adj_range = limits.min_perf_pct * range / 100; + adj_range = limits->min_perf_pct * range / 100; min = hw_min + adj_range; value &= ~HWP_MIN_PERF(~0L); value |= HWP_MIN_PERF(min); - adj_range = limits.max_perf_pct * range / 100; + adj_range = limits->max_perf_pct * range / 100; max = hw_min + adj_range; - if (limits.no_turbo) { + if (limits->no_turbo) { hw_max = HWP_GUARANTEED_PERF(cap); if (hw_max < max) max = hw_max; @@ -510,7 +529,7 @@ static void __init intel_pstate_debug_expose_params(void) static ssize_t show_##file_name \ (struct kobject *kobj, struct attribute *attr, char *buf) \ { \ - return sprintf(buf, "%u\n", limits.object); \ + return sprintf(buf, "%u\n", limits->object); \ } static ssize_t show_turbo_pct(struct kobject *kobj, @@ -546,10 +565,10 @@ static ssize_t show_no_turbo(struct kobject *kobj, ssize_t ret; update_turbo_state(); - if (limits.turbo_disabled) - ret = sprintf(buf, "%u\n", limits.turbo_disabled); + if (limits->turbo_disabled) + ret = sprintf(buf, "%u\n", limits->turbo_disabled); else - ret = sprintf(buf, "%u\n", limits.no_turbo); + ret = sprintf(buf, "%u\n", limits->no_turbo); return ret; } @@ -565,12 +584,12 @@ static ssize_t store_no_turbo(struct kobject *a, struct attribute *b, return -EINVAL; update_turbo_state(); - if (limits.turbo_disabled) { + if (limits->turbo_disabled) { pr_warn("intel_pstate: Turbo disabled by BIOS or unavailable on processor\n"); return -EPERM; } - limits.no_turbo = clamp_t(int, input, 0, 1); + limits->no_turbo = clamp_t(int, input, 0, 1); if (hwp_active) intel_pstate_hwp_set(); @@ -588,11 +607,15 @@ static ssize_t store_max_perf_pct(struct kobject *a, struct attribute *b, if (ret != 1) return -EINVAL; - limits.max_sysfs_pct = clamp_t(int, input, 0 , 100); - limits.max_perf_pct = min(limits.max_policy_pct, limits.max_sysfs_pct); - limits.max_perf_pct = max(limits.min_policy_pct, limits.max_perf_pct); - limits.max_perf_pct = max(limits.min_perf_pct, limits.max_perf_pct); - limits.max_perf = div_fp(int_tofp(limits.max_perf_pct), int_tofp(100)); + limits->max_sysfs_pct = clamp_t(int, input, 0 , 100); + limits->max_perf_pct = min(limits->max_policy_pct, + limits->max_sysfs_pct); + limits->max_perf_pct = max(limits->min_policy_pct, + limits->max_perf_pct); + limits->max_perf_pct = max(limits->min_perf_pct, + limits->max_perf_pct); + limits->max_perf = div_fp(int_tofp(limits->max_perf_pct), + int_tofp(100)); if (hwp_active) intel_pstate_hwp_set(); @@ -609,11 +632,15 @@ static ssize_t store_min_perf_pct(struct kobject *a, struct attribute *b, if (ret != 1) return -EINVAL; - limits.min_sysfs_pct = clamp_t(int, input, 0 , 100); - limits.min_perf_pct = max(limits.min_policy_pct, limits.min_sysfs_pct); - limits.min_perf_pct = min(limits.max_policy_pct, limits.min_perf_pct); - limits.min_perf_pct = min(limits.max_perf_pct, limits.min_perf_pct); - limits.min_perf = div_fp(int_tofp(limits.min_perf_pct), int_tofp(100)); + limits->min_sysfs_pct = clamp_t(int, input, 0 , 100); + limits->min_perf_pct = max(limits->min_policy_pct, + limits->min_sysfs_pct); + limits->min_perf_pct = min(limits->max_policy_pct, + limits->min_perf_pct); + limits->min_perf_pct = min(limits->max_perf_pct, + limits->min_perf_pct); + limits->min_perf = div_fp(int_tofp(limits->min_perf_pct), + int_tofp(100)); if (hwp_active) intel_pstate_hwp_set(); @@ -693,7 +720,7 @@ static void byt_set_pstate(struct cpudata *cpudata, int pstate) u32 vid; val = (u64)pstate << 8; - if (limits.no_turbo && !limits.turbo_disabled) + if (limits->no_turbo && !limits->turbo_disabled) val |= (u64)1 << 32; vid_fp = cpudata->vid.min + mul_fp( @@ -822,7 +849,7 @@ static void core_set_pstate(struct cpudata *cpudata, int pstate) u64 val; val = (u64)pstate << 8; - if (limits.no_turbo && !limits.turbo_disabled) + if (limits->no_turbo && !limits->turbo_disabled) val |= (u64)1 << 32; wrmsrl_on_cpu(cpudata->cpu, MSR_IA32_PERF_CTL, val); @@ -905,7 +932,7 @@ static void intel_pstate_get_min_max(struct cpudata *cpu, int *min, int *max) int max_perf_adj; int min_perf; - if (limits.no_turbo || limits.turbo_disabled) + if (limits->no_turbo || limits->turbo_disabled) max_perf = cpu->pstate.max_pstate; /* @@ -913,21 +940,21 @@ static void intel_pstate_get_min_max(struct cpudata *cpu, int *min, int *max) * policy, or by cpu specific default values determined through * experimentation. */ - if (limits.max_perf_ctl && limits.max_sysfs_pct >= - limits.max_policy_pct) { - *max = limits.max_perf_ctl; + if (limits->max_perf_ctl && limits->max_sysfs_pct >= + limits->max_policy_pct) { + *max = limits->max_perf_ctl; } else { max_perf_adj = fp_toint(mul_fp(int_tofp(max_perf), - limits.max_perf)); + limits->max_perf)); *max = clamp_t(int, max_perf_adj, cpu->pstate.min_pstate, cpu->pstate.turbo_pstate); } - if (limits.min_perf_ctl) { - *min = limits.min_perf_ctl; + if (limits->min_perf_ctl) { + *min = limits->min_perf_ctl; } else { min_perf = fp_toint(mul_fp(int_tofp(max_perf), - limits.min_perf)); + limits->min_perf)); *min = clamp_t(int, min_perf, cpu->pstate.min_pstate, max_perf); } } @@ -1215,34 +1242,35 @@ static int intel_pstate_set_policy(struct cpufreq_policy *policy) if (policy->policy == CPUFREQ_POLICY_PERFORMANCE && policy->max >= policy->cpuinfo.max_freq) { - limits.min_policy_pct = 100; - limits.min_perf_pct = 100; - limits.min_perf = int_tofp(1); - limits.max_policy_pct = 100; - limits.max_perf_pct = 100; - limits.max_perf = int_tofp(1); - limits.no_turbo = 0; - limits.max_perf_ctl = 0; - limits.min_perf_ctl = 0; + pr_debug("intel_pstate: set performance\n"); + limits = &performance_limits; return 0; } - limits.min_policy_pct = (policy->min * 100) / policy->cpuinfo.max_freq; - limits.min_policy_pct = clamp_t(int, limits.min_policy_pct, 0 , 100); - limits.max_policy_pct = (policy->max * 100) / policy->cpuinfo.max_freq; - limits.max_policy_pct = clamp_t(int, limits.max_policy_pct, 0 , 100); + pr_debug("intel_pstate: set powersave\n"); + limits = &powersave_limits; + limits->min_policy_pct = (policy->min * 100) / policy->cpuinfo.max_freq; + limits->min_policy_pct = clamp_t(int, limits->min_policy_pct, 0 , 100); + limits->max_policy_pct = (policy->max * 100) / policy->cpuinfo.max_freq; + limits->max_policy_pct = clamp_t(int, limits->max_policy_pct, 0 , 100); /* Normalize user input to [min_policy_pct, max_policy_pct] */ - limits.min_perf_pct = max(limits.min_policy_pct, limits.min_sysfs_pct); - limits.min_perf_pct = min(limits.max_policy_pct, limits.min_perf_pct); - limits.max_perf_pct = min(limits.max_policy_pct, limits.max_sysfs_pct); - limits.max_perf_pct = max(limits.min_policy_pct, limits.max_perf_pct); + limits->min_perf_pct = max(limits->min_policy_pct, + limits->min_sysfs_pct); + limits->min_perf_pct = min(limits->max_policy_pct, + limits->min_perf_pct); + limits->max_perf_pct = min(limits->max_policy_pct, + limits->max_sysfs_pct); + limits->max_perf_pct = max(limits->min_policy_pct, + limits->max_perf_pct); /* Make sure min_perf_pct <= max_perf_pct */ - limits.min_perf_pct = min(limits.max_perf_pct, limits.min_perf_pct); + limits->min_perf_pct = min(limits->max_perf_pct, limits->min_perf_pct); - limits.min_perf = div_fp(int_tofp(limits.min_perf_pct), int_tofp(100)); - limits.max_perf = div_fp(int_tofp(limits.max_perf_pct), int_tofp(100)); + limits->min_perf = div_fp(int_tofp(limits->min_perf_pct), + int_tofp(100)); + limits->max_perf = div_fp(int_tofp(limits->max_perf_pct), + int_tofp(100)); #if IS_ENABLED(CONFIG_ACPI) cpu = all_cpu_data[policy->cpu]; @@ -1251,14 +1279,14 @@ static int intel_pstate_set_policy(struct cpufreq_policy *policy) control = convert_to_native_pstate_format(cpu, i); if (control * cpu->pstate.scaling == policy->max) - limits.max_perf_ctl = control; + limits->max_perf_ctl = control; if (control * cpu->pstate.scaling == policy->min) - limits.min_perf_ctl = control; + limits->min_perf_ctl = control; } pr_debug("intel_pstate: max %u policy_max %u perf_ctl [0x%x-0x%x]\n", - policy->cpuinfo.max_freq, policy->max, limits.min_perf_ctl, - limits.max_perf_ctl); + policy->cpuinfo.max_freq, policy->max, limits->min_perf_ctl, + limits->max_perf_ctl); #endif if (hwp_active) @@ -1303,7 +1331,7 @@ static int intel_pstate_cpu_init(struct cpufreq_policy *policy) cpu = all_cpu_data[policy->cpu]; - if (limits.min_perf_pct == 100 && limits.max_perf_pct == 100) + if (limits->min_perf_pct == 100 && limits->max_perf_pct == 100) policy->policy = CPUFREQ_POLICY_PERFORMANCE; else policy->policy = CPUFREQ_POLICY_POWERSAVE; -- GitLab