linux_dsm_epyc7002/arch/x86/kernel/itmt.c

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x86: Enable Intel Turbo Boost Max Technology 3.0 On platforms supporting Intel Turbo Boost Max Technology 3.0, the maximum turbo frequencies of some cores in a CPU package may be higher than for the other cores in the same package. In that case, better performance (and possibly lower energy consumption as well) can be achieved by making the scheduler prefer to run tasks on the CPUs with higher max turbo frequencies. To that end, set up a core priority metric to abstract the core preferences based on the maximum turbo frequency. In that metric, the cores with higher maximum turbo frequencies are higher-priority than the other cores in the same package and that causes the scheduler to favor them when making load-balancing decisions using the asymmertic packing approach. At the same time, the priority of SMT threads with a higher CPU number is reduced so as to avoid scheduling tasks on all of the threads that belong to a favored core before all of the other cores have been given a task to run. The priority metric will be initialized by the P-state driver with the help of the sched_set_itmt_core_prio() function. The P-state driver will also determine whether or not ITMT is supported by the platform and will call sched_set_itmt_support() to indicate that. Co-developed-by: Peter Zijlstra (Intel) <peterz@infradead.org> Co-developed-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com> Cc: linux-pm@vger.kernel.org Cc: peterz@infradead.org Cc: jolsa@redhat.com Cc: rjw@rjwysocki.net Cc: linux-acpi@vger.kernel.org Cc: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Cc: bp@suse.de Link: http://lkml.kernel.org/r/cd401ccdff88f88c8349314febdc25d51f7c48f7.1479844244.git.tim.c.chen@linux.intel.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-11-23 03:23:55 +07:00
/*
* itmt.c: Support Intel Turbo Boost Max Technology 3.0
*
* (C) Copyright 2016 Intel Corporation
* Author: Tim Chen <tim.c.chen@linux.intel.com>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; version 2
* of the License.
*
* On platforms supporting Intel Turbo Boost Max Technology 3.0, (ITMT),
* the maximum turbo frequencies of some cores in a CPU package may be
* higher than for the other cores in the same package. In that case,
* better performance can be achieved by making the scheduler prefer
* to run tasks on the CPUs with higher max turbo frequencies.
*
* This file provides functions and data structures for enabling the
* scheduler to favor scheduling on cores can be boosted to a higher
* frequency under ITMT.
*/
#include <linux/sched.h>
#include <linux/cpumask.h>
#include <linux/cpuset.h>
#include <asm/mutex.h>
#include <linux/sched.h>
#include <linux/sysctl.h>
#include <linux/nodemask.h>
static DEFINE_MUTEX(itmt_update_mutex);
DEFINE_PER_CPU_READ_MOSTLY(int, sched_core_priority);
/* Boolean to track if system has ITMT capabilities */
static bool __read_mostly sched_itmt_capable;
/*
* Boolean to control whether we want to move processes to cpu capable
* of higher turbo frequency for cpus supporting Intel Turbo Boost Max
* Technology 3.0.
*
* It can be set via /proc/sys/kernel/sched_itmt_enabled
*/
unsigned int __read_mostly sysctl_sched_itmt_enabled;
static int sched_itmt_update_handler(struct ctl_table *table, int write,
void __user *buffer, size_t *lenp,
loff_t *ppos)
{
unsigned int old_sysctl;
int ret;
mutex_lock(&itmt_update_mutex);
if (!sched_itmt_capable) {
mutex_unlock(&itmt_update_mutex);
return -EINVAL;
}
old_sysctl = sysctl_sched_itmt_enabled;
ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
if (!ret && write && old_sysctl != sysctl_sched_itmt_enabled) {
x86_topology_update = true;
rebuild_sched_domains();
}
mutex_unlock(&itmt_update_mutex);
return ret;
}
static unsigned int zero;
static unsigned int one = 1;
static struct ctl_table itmt_kern_table[] = {
{
.procname = "sched_itmt_enabled",
.data = &sysctl_sched_itmt_enabled,
.maxlen = sizeof(unsigned int),
.mode = 0644,
.proc_handler = sched_itmt_update_handler,
.extra1 = &zero,
.extra2 = &one,
},
{}
};
static struct ctl_table itmt_root_table[] = {
{
.procname = "kernel",
.mode = 0555,
.child = itmt_kern_table,
},
{}
};
static struct ctl_table_header *itmt_sysctl_header;
x86: Enable Intel Turbo Boost Max Technology 3.0 On platforms supporting Intel Turbo Boost Max Technology 3.0, the maximum turbo frequencies of some cores in a CPU package may be higher than for the other cores in the same package. In that case, better performance (and possibly lower energy consumption as well) can be achieved by making the scheduler prefer to run tasks on the CPUs with higher max turbo frequencies. To that end, set up a core priority metric to abstract the core preferences based on the maximum turbo frequency. In that metric, the cores with higher maximum turbo frequencies are higher-priority than the other cores in the same package and that causes the scheduler to favor them when making load-balancing decisions using the asymmertic packing approach. At the same time, the priority of SMT threads with a higher CPU number is reduced so as to avoid scheduling tasks on all of the threads that belong to a favored core before all of the other cores have been given a task to run. The priority metric will be initialized by the P-state driver with the help of the sched_set_itmt_core_prio() function. The P-state driver will also determine whether or not ITMT is supported by the platform and will call sched_set_itmt_support() to indicate that. Co-developed-by: Peter Zijlstra (Intel) <peterz@infradead.org> Co-developed-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com> Cc: linux-pm@vger.kernel.org Cc: peterz@infradead.org Cc: jolsa@redhat.com Cc: rjw@rjwysocki.net Cc: linux-acpi@vger.kernel.org Cc: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Cc: bp@suse.de Link: http://lkml.kernel.org/r/cd401ccdff88f88c8349314febdc25d51f7c48f7.1479844244.git.tim.c.chen@linux.intel.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-11-23 03:23:55 +07:00
/**
* sched_set_itmt_support() - Indicate platform supports ITMT
*
* This function is used by the OS to indicate to scheduler that the platform
* is capable of supporting the ITMT feature.
*
* The current scheme has the pstate driver detects if the system
* is ITMT capable and call sched_set_itmt_support.
*
* This must be done only after sched_set_itmt_core_prio
* has been called to set the cpus' priorities.
* It must not be called with cpu hot plug lock
* held as we need to acquire the lock to rebuild sched domains
* later.
*
* Return: 0 on success
x86: Enable Intel Turbo Boost Max Technology 3.0 On platforms supporting Intel Turbo Boost Max Technology 3.0, the maximum turbo frequencies of some cores in a CPU package may be higher than for the other cores in the same package. In that case, better performance (and possibly lower energy consumption as well) can be achieved by making the scheduler prefer to run tasks on the CPUs with higher max turbo frequencies. To that end, set up a core priority metric to abstract the core preferences based on the maximum turbo frequency. In that metric, the cores with higher maximum turbo frequencies are higher-priority than the other cores in the same package and that causes the scheduler to favor them when making load-balancing decisions using the asymmertic packing approach. At the same time, the priority of SMT threads with a higher CPU number is reduced so as to avoid scheduling tasks on all of the threads that belong to a favored core before all of the other cores have been given a task to run. The priority metric will be initialized by the P-state driver with the help of the sched_set_itmt_core_prio() function. The P-state driver will also determine whether or not ITMT is supported by the platform and will call sched_set_itmt_support() to indicate that. Co-developed-by: Peter Zijlstra (Intel) <peterz@infradead.org> Co-developed-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com> Cc: linux-pm@vger.kernel.org Cc: peterz@infradead.org Cc: jolsa@redhat.com Cc: rjw@rjwysocki.net Cc: linux-acpi@vger.kernel.org Cc: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Cc: bp@suse.de Link: http://lkml.kernel.org/r/cd401ccdff88f88c8349314febdc25d51f7c48f7.1479844244.git.tim.c.chen@linux.intel.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-11-23 03:23:55 +07:00
*/
int sched_set_itmt_support(void)
x86: Enable Intel Turbo Boost Max Technology 3.0 On platforms supporting Intel Turbo Boost Max Technology 3.0, the maximum turbo frequencies of some cores in a CPU package may be higher than for the other cores in the same package. In that case, better performance (and possibly lower energy consumption as well) can be achieved by making the scheduler prefer to run tasks on the CPUs with higher max turbo frequencies. To that end, set up a core priority metric to abstract the core preferences based on the maximum turbo frequency. In that metric, the cores with higher maximum turbo frequencies are higher-priority than the other cores in the same package and that causes the scheduler to favor them when making load-balancing decisions using the asymmertic packing approach. At the same time, the priority of SMT threads with a higher CPU number is reduced so as to avoid scheduling tasks on all of the threads that belong to a favored core before all of the other cores have been given a task to run. The priority metric will be initialized by the P-state driver with the help of the sched_set_itmt_core_prio() function. The P-state driver will also determine whether or not ITMT is supported by the platform and will call sched_set_itmt_support() to indicate that. Co-developed-by: Peter Zijlstra (Intel) <peterz@infradead.org> Co-developed-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com> Cc: linux-pm@vger.kernel.org Cc: peterz@infradead.org Cc: jolsa@redhat.com Cc: rjw@rjwysocki.net Cc: linux-acpi@vger.kernel.org Cc: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Cc: bp@suse.de Link: http://lkml.kernel.org/r/cd401ccdff88f88c8349314febdc25d51f7c48f7.1479844244.git.tim.c.chen@linux.intel.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-11-23 03:23:55 +07:00
{
mutex_lock(&itmt_update_mutex);
if (sched_itmt_capable) {
mutex_unlock(&itmt_update_mutex);
return 0;
}
itmt_sysctl_header = register_sysctl_table(itmt_root_table);
if (!itmt_sysctl_header) {
mutex_unlock(&itmt_update_mutex);
return -ENOMEM;
}
x86: Enable Intel Turbo Boost Max Technology 3.0 On platforms supporting Intel Turbo Boost Max Technology 3.0, the maximum turbo frequencies of some cores in a CPU package may be higher than for the other cores in the same package. In that case, better performance (and possibly lower energy consumption as well) can be achieved by making the scheduler prefer to run tasks on the CPUs with higher max turbo frequencies. To that end, set up a core priority metric to abstract the core preferences based on the maximum turbo frequency. In that metric, the cores with higher maximum turbo frequencies are higher-priority than the other cores in the same package and that causes the scheduler to favor them when making load-balancing decisions using the asymmertic packing approach. At the same time, the priority of SMT threads with a higher CPU number is reduced so as to avoid scheduling tasks on all of the threads that belong to a favored core before all of the other cores have been given a task to run. The priority metric will be initialized by the P-state driver with the help of the sched_set_itmt_core_prio() function. The P-state driver will also determine whether or not ITMT is supported by the platform and will call sched_set_itmt_support() to indicate that. Co-developed-by: Peter Zijlstra (Intel) <peterz@infradead.org> Co-developed-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com> Cc: linux-pm@vger.kernel.org Cc: peterz@infradead.org Cc: jolsa@redhat.com Cc: rjw@rjwysocki.net Cc: linux-acpi@vger.kernel.org Cc: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Cc: bp@suse.de Link: http://lkml.kernel.org/r/cd401ccdff88f88c8349314febdc25d51f7c48f7.1479844244.git.tim.c.chen@linux.intel.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-11-23 03:23:55 +07:00
sched_itmt_capable = true;
sysctl_sched_itmt_enabled = 1;
if (sysctl_sched_itmt_enabled) {
x86_topology_update = true;
rebuild_sched_domains();
}
x86: Enable Intel Turbo Boost Max Technology 3.0 On platforms supporting Intel Turbo Boost Max Technology 3.0, the maximum turbo frequencies of some cores in a CPU package may be higher than for the other cores in the same package. In that case, better performance (and possibly lower energy consumption as well) can be achieved by making the scheduler prefer to run tasks on the CPUs with higher max turbo frequencies. To that end, set up a core priority metric to abstract the core preferences based on the maximum turbo frequency. In that metric, the cores with higher maximum turbo frequencies are higher-priority than the other cores in the same package and that causes the scheduler to favor them when making load-balancing decisions using the asymmertic packing approach. At the same time, the priority of SMT threads with a higher CPU number is reduced so as to avoid scheduling tasks on all of the threads that belong to a favored core before all of the other cores have been given a task to run. The priority metric will be initialized by the P-state driver with the help of the sched_set_itmt_core_prio() function. The P-state driver will also determine whether or not ITMT is supported by the platform and will call sched_set_itmt_support() to indicate that. Co-developed-by: Peter Zijlstra (Intel) <peterz@infradead.org> Co-developed-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com> Cc: linux-pm@vger.kernel.org Cc: peterz@infradead.org Cc: jolsa@redhat.com Cc: rjw@rjwysocki.net Cc: linux-acpi@vger.kernel.org Cc: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Cc: bp@suse.de Link: http://lkml.kernel.org/r/cd401ccdff88f88c8349314febdc25d51f7c48f7.1479844244.git.tim.c.chen@linux.intel.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-11-23 03:23:55 +07:00
mutex_unlock(&itmt_update_mutex);
return 0;
x86: Enable Intel Turbo Boost Max Technology 3.0 On platforms supporting Intel Turbo Boost Max Technology 3.0, the maximum turbo frequencies of some cores in a CPU package may be higher than for the other cores in the same package. In that case, better performance (and possibly lower energy consumption as well) can be achieved by making the scheduler prefer to run tasks on the CPUs with higher max turbo frequencies. To that end, set up a core priority metric to abstract the core preferences based on the maximum turbo frequency. In that metric, the cores with higher maximum turbo frequencies are higher-priority than the other cores in the same package and that causes the scheduler to favor them when making load-balancing decisions using the asymmertic packing approach. At the same time, the priority of SMT threads with a higher CPU number is reduced so as to avoid scheduling tasks on all of the threads that belong to a favored core before all of the other cores have been given a task to run. The priority metric will be initialized by the P-state driver with the help of the sched_set_itmt_core_prio() function. The P-state driver will also determine whether or not ITMT is supported by the platform and will call sched_set_itmt_support() to indicate that. Co-developed-by: Peter Zijlstra (Intel) <peterz@infradead.org> Co-developed-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com> Cc: linux-pm@vger.kernel.org Cc: peterz@infradead.org Cc: jolsa@redhat.com Cc: rjw@rjwysocki.net Cc: linux-acpi@vger.kernel.org Cc: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Cc: bp@suse.de Link: http://lkml.kernel.org/r/cd401ccdff88f88c8349314febdc25d51f7c48f7.1479844244.git.tim.c.chen@linux.intel.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-11-23 03:23:55 +07:00
}
/**
* sched_clear_itmt_support() - Revoke platform's support of ITMT
*
* This function is used by the OS to indicate that it has
* revoked the platform's support of ITMT feature.
*
* It must not be called with cpu hot plug lock
* held as we need to acquire the lock to rebuild sched domains
* later.
x86: Enable Intel Turbo Boost Max Technology 3.0 On platforms supporting Intel Turbo Boost Max Technology 3.0, the maximum turbo frequencies of some cores in a CPU package may be higher than for the other cores in the same package. In that case, better performance (and possibly lower energy consumption as well) can be achieved by making the scheduler prefer to run tasks on the CPUs with higher max turbo frequencies. To that end, set up a core priority metric to abstract the core preferences based on the maximum turbo frequency. In that metric, the cores with higher maximum turbo frequencies are higher-priority than the other cores in the same package and that causes the scheduler to favor them when making load-balancing decisions using the asymmertic packing approach. At the same time, the priority of SMT threads with a higher CPU number is reduced so as to avoid scheduling tasks on all of the threads that belong to a favored core before all of the other cores have been given a task to run. The priority metric will be initialized by the P-state driver with the help of the sched_set_itmt_core_prio() function. The P-state driver will also determine whether or not ITMT is supported by the platform and will call sched_set_itmt_support() to indicate that. Co-developed-by: Peter Zijlstra (Intel) <peterz@infradead.org> Co-developed-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com> Cc: linux-pm@vger.kernel.org Cc: peterz@infradead.org Cc: jolsa@redhat.com Cc: rjw@rjwysocki.net Cc: linux-acpi@vger.kernel.org Cc: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Cc: bp@suse.de Link: http://lkml.kernel.org/r/cd401ccdff88f88c8349314febdc25d51f7c48f7.1479844244.git.tim.c.chen@linux.intel.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-11-23 03:23:55 +07:00
*/
void sched_clear_itmt_support(void)
{
mutex_lock(&itmt_update_mutex);
if (!sched_itmt_capable) {
mutex_unlock(&itmt_update_mutex);
return;
}
x86: Enable Intel Turbo Boost Max Technology 3.0 On platforms supporting Intel Turbo Boost Max Technology 3.0, the maximum turbo frequencies of some cores in a CPU package may be higher than for the other cores in the same package. In that case, better performance (and possibly lower energy consumption as well) can be achieved by making the scheduler prefer to run tasks on the CPUs with higher max turbo frequencies. To that end, set up a core priority metric to abstract the core preferences based on the maximum turbo frequency. In that metric, the cores with higher maximum turbo frequencies are higher-priority than the other cores in the same package and that causes the scheduler to favor them when making load-balancing decisions using the asymmertic packing approach. At the same time, the priority of SMT threads with a higher CPU number is reduced so as to avoid scheduling tasks on all of the threads that belong to a favored core before all of the other cores have been given a task to run. The priority metric will be initialized by the P-state driver with the help of the sched_set_itmt_core_prio() function. The P-state driver will also determine whether or not ITMT is supported by the platform and will call sched_set_itmt_support() to indicate that. Co-developed-by: Peter Zijlstra (Intel) <peterz@infradead.org> Co-developed-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com> Cc: linux-pm@vger.kernel.org Cc: peterz@infradead.org Cc: jolsa@redhat.com Cc: rjw@rjwysocki.net Cc: linux-acpi@vger.kernel.org Cc: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Cc: bp@suse.de Link: http://lkml.kernel.org/r/cd401ccdff88f88c8349314febdc25d51f7c48f7.1479844244.git.tim.c.chen@linux.intel.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-11-23 03:23:55 +07:00
sched_itmt_capable = false;
if (itmt_sysctl_header) {
unregister_sysctl_table(itmt_sysctl_header);
itmt_sysctl_header = NULL;
}
if (sysctl_sched_itmt_enabled) {
/* disable sched_itmt if we are no longer ITMT capable */
sysctl_sched_itmt_enabled = 0;
x86_topology_update = true;
rebuild_sched_domains();
}
x86: Enable Intel Turbo Boost Max Technology 3.0 On platforms supporting Intel Turbo Boost Max Technology 3.0, the maximum turbo frequencies of some cores in a CPU package may be higher than for the other cores in the same package. In that case, better performance (and possibly lower energy consumption as well) can be achieved by making the scheduler prefer to run tasks on the CPUs with higher max turbo frequencies. To that end, set up a core priority metric to abstract the core preferences based on the maximum turbo frequency. In that metric, the cores with higher maximum turbo frequencies are higher-priority than the other cores in the same package and that causes the scheduler to favor them when making load-balancing decisions using the asymmertic packing approach. At the same time, the priority of SMT threads with a higher CPU number is reduced so as to avoid scheduling tasks on all of the threads that belong to a favored core before all of the other cores have been given a task to run. The priority metric will be initialized by the P-state driver with the help of the sched_set_itmt_core_prio() function. The P-state driver will also determine whether or not ITMT is supported by the platform and will call sched_set_itmt_support() to indicate that. Co-developed-by: Peter Zijlstra (Intel) <peterz@infradead.org> Co-developed-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com> Cc: linux-pm@vger.kernel.org Cc: peterz@infradead.org Cc: jolsa@redhat.com Cc: rjw@rjwysocki.net Cc: linux-acpi@vger.kernel.org Cc: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Cc: bp@suse.de Link: http://lkml.kernel.org/r/cd401ccdff88f88c8349314febdc25d51f7c48f7.1479844244.git.tim.c.chen@linux.intel.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-11-23 03:23:55 +07:00
mutex_unlock(&itmt_update_mutex);
}
int arch_asym_cpu_priority(int cpu)
{
return per_cpu(sched_core_priority, cpu);
}
/**
* sched_set_itmt_core_prio() - Set CPU priority based on ITMT
* @prio: Priority of cpu core
* @core_cpu: The cpu number associated with the core
*
* The pstate driver will find out the max boost frequency
* and call this function to set a priority proportional
* to the max boost frequency. CPU with higher boost
* frequency will receive higher priority.
*
* No need to rebuild sched domain after updating
* the CPU priorities. The sched domains have no
* dependency on CPU priorities.
*/
void sched_set_itmt_core_prio(int prio, int core_cpu)
{
int cpu, i = 1;
for_each_cpu(cpu, topology_sibling_cpumask(core_cpu)) {
int smt_prio;
/*
* Ensure that the siblings are moved to the end
* of the priority chain and only used when
* all other high priority cpus are out of capacity.
*/
smt_prio = prio * smp_num_siblings / i;
per_cpu(sched_core_priority, cpu) = smt_prio;
i++;
}
}