78eb4ea25c
const qualify the struct ctl_table argument in the proc_handler function signatures. This is a prerequisite to moving the static ctl_table structs into .rodata data which will ensure that proc_handler function pointers cannot be modified. This patch has been generated by the following coccinelle script: ``` virtual patch @r1@ identifier ctl, write, buffer, lenp, ppos; identifier func !~ "appldata_(timer|interval)_handler|sched_(rt|rr)_handler|rds_tcp_skbuf_handler|proc_sctp_do_(hmac_alg|rto_min|rto_max|udp_port|alpha_beta|auth|probe_interval)"; @@ int func( - struct ctl_table *ctl + const struct ctl_table *ctl ,int write, void *buffer, size_t *lenp, loff_t *ppos); @r2@ identifier func, ctl, write, buffer, lenp, ppos; @@ int func( - struct ctl_table *ctl + const struct ctl_table *ctl ,int write, void *buffer, size_t *lenp, loff_t *ppos) { ... } @r3@ identifier func; @@ int func( - struct ctl_table * + const struct ctl_table * ,int , void *, size_t *, loff_t *); @r4@ identifier func, ctl; @@ int func( - struct ctl_table *ctl + const struct ctl_table *ctl ,int , void *, size_t *, loff_t *); @r5@ identifier func, write, buffer, lenp, ppos; @@ int func( - struct ctl_table * + const struct ctl_table * ,int write, void *buffer, size_t *lenp, loff_t *ppos); ``` * Code formatting was adjusted in xfs_sysctl.c to comply with code conventions. The xfs_stats_clear_proc_handler, xfs_panic_mask_proc_handler and xfs_deprecated_dointvec_minmax where adjusted. * The ctl_table argument in proc_watchdog_common was const qualified. This is called from a proc_handler itself and is calling back into another proc_handler, making it necessary to change it as part of the proc_handler migration. Co-developed-by: Thomas Weißschuh <linux@weissschuh.net> Signed-off-by: Thomas Weißschuh <linux@weissschuh.net> Co-developed-by: Joel Granados <j.granados@samsung.com> Signed-off-by: Joel Granados <j.granados@samsung.com>
183 lines
4.7 KiB
C
183 lines
4.7 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
|
|
/*
|
|
* itmt.c: Support Intel Turbo Boost Max Technology 3.0
|
|
*
|
|
* (C) Copyright 2016 Intel Corporation
|
|
* Author: Tim Chen <tim.c.chen@linux.intel.com>
|
|
*
|
|
* 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 <linux/mutex.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(const struct ctl_table *table, int write,
|
|
void *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 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 = SYSCTL_ZERO,
|
|
.extra2 = SYSCTL_ONE,
|
|
},
|
|
};
|
|
|
|
static struct ctl_table_header *itmt_sysctl_header;
|
|
|
|
/**
|
|
* 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
|
|
*/
|
|
int sched_set_itmt_support(void)
|
|
{
|
|
mutex_lock(&itmt_update_mutex);
|
|
|
|
if (sched_itmt_capable) {
|
|
mutex_unlock(&itmt_update_mutex);
|
|
return 0;
|
|
}
|
|
|
|
itmt_sysctl_header = register_sysctl("kernel", itmt_kern_table);
|
|
if (!itmt_sysctl_header) {
|
|
mutex_unlock(&itmt_update_mutex);
|
|
return -ENOMEM;
|
|
}
|
|
|
|
sched_itmt_capable = true;
|
|
|
|
sysctl_sched_itmt_enabled = 1;
|
|
|
|
x86_topology_update = true;
|
|
rebuild_sched_domains();
|
|
|
|
mutex_unlock(&itmt_update_mutex);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* 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.
|
|
*/
|
|
void sched_clear_itmt_support(void)
|
|
{
|
|
mutex_lock(&itmt_update_mutex);
|
|
|
|
if (!sched_itmt_capable) {
|
|
mutex_unlock(&itmt_update_mutex);
|
|
return;
|
|
}
|
|
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();
|
|
}
|
|
|
|
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
|
|
* @cpu: The CPU number
|
|
*
|
|
* The pstate driver will find out the max boost frequency
|
|
* and call this function to set a priority proportional
|
|
* to the max boost frequency. CPUs 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 cpu)
|
|
{
|
|
per_cpu(sched_core_priority, cpu) = prio;
|
|
}
|