freebsd-skq/sys/sparc64/include/smp.h
mav eb4931dc6c Refactor timer management code with priority to one-shot operation mode.
The main goal of this is to generate timer interrupts only when there is
some work to do. When CPU is busy interrupts are generating at full rate
of hz + stathz to fullfill scheduler and timekeeping requirements. But
when CPU is idle, only minimum set of interrupts (down to 8 interrupts per
second per CPU now), needed to handle scheduled callouts is executed.
This allows significantly increase idle CPU sleep time, increasing effect
of static power-saving technologies. Also it should reduce host CPU load
on virtualized systems, when guest system is idle.

There is set of tunables, also available as writable sysctls, allowing to
control wanted event timer subsystem behavior:
  kern.eventtimer.timer - allows to choose event timer hardware to use.
On x86 there is up to 4 different kinds of timers. Depending on whether
chosen timer is per-CPU, behavior of other options slightly differs.
  kern.eventtimer.periodic - allows to choose periodic and one-shot
operation mode. In periodic mode, current timer hardware taken as the only
source of time for time events. This mode is quite alike to previous kernel
behavior. One-shot mode instead uses currently selected time counter
hardware to schedule all needed events one by one and program timer to
generate interrupt exactly in specified time. Default value depends of
chosen timer capabilities, but one-shot mode is preferred, until other is
forced by user or hardware.
  kern.eventtimer.singlemul - in periodic mode specifies how much times
higher timer frequency should be, to not strictly alias hardclock() and
statclock() events. Default values are 2 and 4, but could be reduced to 1
if extra interrupts are unwanted.
  kern.eventtimer.idletick - makes each CPU to receive every timer interrupt
independently of whether they busy or not. By default this options is
disabled. If chosen timer is per-CPU and runs in periodic mode, this option
has no effect - all interrupts are generating.

As soon as this patch modifies cpu_idle() on some platforms, I have also
refactored one on x86. Now it makes use of MONITOR/MWAIT instrunctions
(if supported) under high sleep/wakeup rate, as fast alternative to other
methods. It allows SMP scheduler to wake up sleeping CPUs much faster
without using IPI, significantly increasing performance on some highly
task-switching loads.

Tested by:	many (on i386, amd64, sparc64 and powerc)
H/W donated by:	Gheorghe Ardelean
Sponsored by:	iXsystems, Inc.
2010-09-13 07:25:35 +00:00

368 lines
7.8 KiB
C

/*-
* Copyright (c) 2001 Jake Burkholder.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD$
*/
#ifndef _MACHINE_SMP_H_
#define _MACHINE_SMP_H_
#ifdef SMP
#define CPU_TICKSYNC 1
#define CPU_STICKSYNC 2
#define CPU_INIT 3
#define CPU_BOOTSTRAP 4
#ifndef LOCORE
#include <sys/proc.h>
#include <sys/sched.h>
#include <machine/intr_machdep.h>
#include <machine/pcb.h>
#include <machine/tte.h>
#define IDR_BUSY 0x0000000000000001ULL
#define IDR_NACK 0x0000000000000002ULL
#define IDR_CHEETAH_ALL_BUSY 0x5555555555555555ULL
#define IDR_CHEETAH_ALL_NACK (~IDR_CHEETAH_ALL_BUSY)
#define IDR_CHEETAH_MAX_BN_PAIRS 32
#define IDR_JALAPENO_MAX_BN_PAIRS 4
#define IDC_ITID_SHIFT 14
#define IDC_BN_SHIFT 24
#define IPI_AST PIL_AST
#define IPI_RENDEZVOUS PIL_RENDEZVOUS
#define IPI_PREEMPT PIL_PREEMPT
#define IPI_HARDCLOCK PIL_HARDCLOCK
#define IPI_STOP PIL_STOP
#define IPI_STOP_HARD PIL_STOP
#define IPI_RETRIES 5000
struct cpu_start_args {
u_int csa_count;
u_int csa_mid;
u_int csa_state;
vm_offset_t csa_pcpu;
u_long csa_tick;
u_long csa_stick;
u_long csa_ver;
struct tte csa_ttes[PCPU_PAGES];
};
struct ipi_cache_args {
cpumask_t ica_mask;
vm_paddr_t ica_pa;
};
struct ipi_rd_args {
cpumask_t ira_mask;
register_t *ira_val;
};
struct ipi_tlb_args {
cpumask_t ita_mask;
struct pmap *ita_pmap;
u_long ita_start;
u_long ita_end;
};
#define ita_va ita_start
struct pcpu;
extern struct pcb stoppcbs[];
void cpu_mp_bootstrap(struct pcpu *pc);
void cpu_mp_shutdown(void);
typedef void cpu_ipi_selected_t(u_int, u_long, u_long, u_long);
extern cpu_ipi_selected_t *cpu_ipi_selected;
typedef void cpu_ipi_single_t(u_int, u_long, u_long, u_long);
extern cpu_ipi_single_t *cpu_ipi_single;
void mp_init(u_int cpu_impl);
extern struct mtx ipi_mtx;
extern struct ipi_cache_args ipi_cache_args;
extern struct ipi_rd_args ipi_rd_args;
extern struct ipi_tlb_args ipi_tlb_args;
extern char *mp_tramp_code;
extern u_long mp_tramp_code_len;
extern u_long mp_tramp_tlb_slots;
extern u_long mp_tramp_func;
extern void mp_startup(void);
extern char tl_ipi_cheetah_dcache_page_inval[];
extern char tl_ipi_spitfire_dcache_page_inval[];
extern char tl_ipi_spitfire_icache_page_inval[];
extern char tl_ipi_level[];
extern char tl_ipi_stick_rd[];
extern char tl_ipi_tick_rd[];
extern char tl_ipi_tlb_context_demap[];
extern char tl_ipi_tlb_page_demap[];
extern char tl_ipi_tlb_range_demap[];
static __inline void
ipi_all_but_self(u_int ipi)
{
cpu_ipi_selected(PCPU_GET(other_cpus), 0, (u_long)tl_ipi_level, ipi);
}
static __inline void
ipi_selected(u_int cpus, u_int ipi)
{
cpu_ipi_selected(cpus, 0, (u_long)tl_ipi_level, ipi);
}
static __inline void
ipi_cpu(int cpu, u_int ipi)
{
cpu_ipi_single(cpu, 0, (u_long)tl_ipi_level, ipi);
}
#if defined(_MACHINE_PMAP_H_) && defined(_SYS_MUTEX_H_)
static __inline void *
ipi_dcache_page_inval(void *func, vm_paddr_t pa)
{
struct ipi_cache_args *ica;
if (smp_cpus == 1)
return (NULL);
sched_pin();
ica = &ipi_cache_args;
mtx_lock_spin(&ipi_mtx);
ica->ica_mask = all_cpus;
ica->ica_pa = pa;
cpu_ipi_selected(PCPU_GET(other_cpus), 0, (u_long)func, (u_long)ica);
return (&ica->ica_mask);
}
static __inline void *
ipi_icache_page_inval(void *func, vm_paddr_t pa)
{
struct ipi_cache_args *ica;
if (smp_cpus == 1)
return (NULL);
sched_pin();
ica = &ipi_cache_args;
mtx_lock_spin(&ipi_mtx);
ica->ica_mask = all_cpus;
ica->ica_pa = pa;
cpu_ipi_selected(PCPU_GET(other_cpus), 0, (u_long)func, (u_long)ica);
return (&ica->ica_mask);
}
static __inline void *
ipi_rd(u_int cpu, void *func, u_long *val)
{
struct ipi_rd_args *ira;
if (smp_cpus == 1)
return (NULL);
sched_pin();
ira = &ipi_rd_args;
mtx_lock_spin(&ipi_mtx);
ira->ira_mask = 1 << cpu | PCPU_GET(cpumask);
ira->ira_val = val;
cpu_ipi_single(cpu, 0, (u_long)func, (u_long)ira);
return (&ira->ira_mask);
}
static __inline void *
ipi_tlb_context_demap(struct pmap *pm)
{
struct ipi_tlb_args *ita;
cpumask_t cpus;
if (smp_cpus == 1)
return (NULL);
sched_pin();
if ((cpus = (pm->pm_active & PCPU_GET(other_cpus))) == 0) {
sched_unpin();
return (NULL);
}
ita = &ipi_tlb_args;
mtx_lock_spin(&ipi_mtx);
ita->ita_mask = cpus | PCPU_GET(cpumask);
ita->ita_pmap = pm;
cpu_ipi_selected(cpus, 0, (u_long)tl_ipi_tlb_context_demap,
(u_long)ita);
return (&ita->ita_mask);
}
static __inline void *
ipi_tlb_page_demap(struct pmap *pm, vm_offset_t va)
{
struct ipi_tlb_args *ita;
cpumask_t cpus;
if (smp_cpus == 1)
return (NULL);
sched_pin();
if ((cpus = (pm->pm_active & PCPU_GET(other_cpus))) == 0) {
sched_unpin();
return (NULL);
}
ita = &ipi_tlb_args;
mtx_lock_spin(&ipi_mtx);
ita->ita_mask = cpus | PCPU_GET(cpumask);
ita->ita_pmap = pm;
ita->ita_va = va;
cpu_ipi_selected(cpus, 0, (u_long)tl_ipi_tlb_page_demap, (u_long)ita);
return (&ita->ita_mask);
}
static __inline void *
ipi_tlb_range_demap(struct pmap *pm, vm_offset_t start, vm_offset_t end)
{
struct ipi_tlb_args *ita;
cpumask_t cpus;
if (smp_cpus == 1)
return (NULL);
sched_pin();
if ((cpus = (pm->pm_active & PCPU_GET(other_cpus))) == 0) {
sched_unpin();
return (NULL);
}
ita = &ipi_tlb_args;
mtx_lock_spin(&ipi_mtx);
ita->ita_mask = cpus | PCPU_GET(cpumask);
ita->ita_pmap = pm;
ita->ita_start = start;
ita->ita_end = end;
cpu_ipi_selected(cpus, 0, (u_long)tl_ipi_tlb_range_demap,
(u_long)ita);
return (&ita->ita_mask);
}
static __inline void
ipi_wait(void *cookie)
{
volatile cpumask_t *mask;
if ((mask = cookie) != NULL) {
atomic_clear_int(mask, PCPU_GET(cpumask));
while (*mask != 0)
;
mtx_unlock_spin(&ipi_mtx);
sched_unpin();
}
}
#endif /* _MACHINE_PMAP_H_ && _SYS_MUTEX_H_ */
#endif /* !LOCORE */
#else
#ifndef LOCORE
static __inline void *
ipi_dcache_page_inval(void *func __unused, vm_paddr_t pa __unused)
{
return (NULL);
}
static __inline void *
ipi_icache_page_inval(void *func __unused, vm_paddr_t pa __unused)
{
return (NULL);
}
static __inline void *
ipi_rd(u_int cpu __unused, void *func __unused, u_long *val __unused)
{
return (NULL);
}
static __inline void *
ipi_tlb_context_demap(struct pmap *pm __unused)
{
return (NULL);
}
static __inline void *
ipi_tlb_page_demap(struct pmap *pm __unused, vm_offset_t va __unused)
{
return (NULL);
}
static __inline void *
ipi_tlb_range_demap(struct pmap *pm __unused, vm_offset_t start __unused,
__unused vm_offset_t end)
{
return (NULL);
}
static __inline void
ipi_wait(void *cookie)
{
}
static __inline void
tl_ipi_cheetah_dcache_page_inval(void)
{
}
static __inline void
tl_ipi_spitfire_dcache_page_inval(void)
{
}
static __inline void
tl_ipi_spitfire_icache_page_inval(void)
{
}
#endif /* !LOCORE */
#endif /* SMP */
#endif /* !_MACHINE_SMP_H_ */