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freebsd-dev/sys/amd64/include/apicvar.h
Alexander Motin a157e42516 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

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/*-
* Copyright (c) 2003 John Baldwin <jhb@FreeBSD.org>
* 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.
* 3. Neither the name of the author nor the names of any co-contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* 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_APICVAR_H_
#define _MACHINE_APICVAR_H_
#include <machine/segments.h>
/*
* Local && I/O APIC variable definitions.
*/
/*
* Layout of local APIC interrupt vectors:
*
* 0xff (255) +-------------+
* | | 15 (Spurious / IPIs / Local Interrupts)
* 0xf0 (240) +-------------+
* | | 14 (I/O Interrupts / Timer)
* 0xe0 (224) +-------------+
* | | 13 (I/O Interrupts)
* 0xd0 (208) +-------------+
* | | 12 (I/O Interrupts)
* 0xc0 (192) +-------------+
* | | 11 (I/O Interrupts)
* 0xb0 (176) +-------------+
* | | 10 (I/O Interrupts)
* 0xa0 (160) +-------------+
* | | 9 (I/O Interrupts)
* 0x90 (144) +-------------+
* | | 8 (I/O Interrupts / System Calls)
* 0x80 (128) +-------------+
* | | 7 (I/O Interrupts)
* 0x70 (112) +-------------+
* | | 6 (I/O Interrupts)
* 0x60 (96) +-------------+
* | | 5 (I/O Interrupts)
* 0x50 (80) +-------------+
* | | 4 (I/O Interrupts)
* 0x40 (64) +-------------+
* | | 3 (I/O Interrupts)
* 0x30 (48) +-------------+
* | | 2 (ATPIC Interrupts)
* 0x20 (32) +-------------+
* | | 1 (Exceptions, traps, faults, etc.)
* 0x10 (16) +-------------+
* | | 0 (Exceptions, traps, faults, etc.)
* 0x00 (0) +-------------+
*
* Note: 0x80 needs to be handled specially and not allocated to an
* I/O device!
*/
#define MAX_APIC_ID 0xfe
#define APIC_ID_ALL 0xff
/* I/O Interrupts are used for external devices such as ISA, PCI, etc. */
#define APIC_IO_INTS (IDT_IO_INTS + 16)
#define APIC_NUM_IOINTS 191
/* The timer interrupt is used for clock handling and drives hardclock, etc. */
#define APIC_TIMER_INT (APIC_IO_INTS + APIC_NUM_IOINTS)
/*
********************* !!! WARNING !!! ******************************
* Each local apic has an interrupt receive fifo that is two entries deep
* for each interrupt priority class (higher 4 bits of interrupt vector).
* Once the fifo is full the APIC can no longer receive interrupts for this
* class and sending IPIs from other CPUs will be blocked.
* To avoid deadlocks there should be no more than two IPI interrupts
* pending at the same time.
* Currently this is guaranteed by dividing the IPIs in two groups that have
* each at most one IPI interrupt pending. The first group is protected by the
* smp_ipi_mtx and waits for the completion of the IPI (Only one IPI user
* at a time) The second group uses a single interrupt and a bitmap to avoid
* redundant IPI interrupts.
*/
/* Interrupts for local APIC LVT entries other than the timer. */
#define APIC_LOCAL_INTS 240
#define APIC_ERROR_INT APIC_LOCAL_INTS
#define APIC_THERMAL_INT (APIC_LOCAL_INTS + 1)
#define APIC_CMC_INT (APIC_LOCAL_INTS + 2)
#define APIC_IPI_INTS (APIC_LOCAL_INTS + 3)
#define IPI_RENDEZVOUS (APIC_IPI_INTS) /* Inter-CPU rendezvous. */
#define IPI_INVLTLB (APIC_IPI_INTS + 1) /* TLB Shootdown IPIs */
#define IPI_INVLPG (APIC_IPI_INTS + 2)
#define IPI_INVLRNG (APIC_IPI_INTS + 3)
#define IPI_INVLCACHE (APIC_IPI_INTS + 4)
/* Vector to handle bitmap based IPIs */
#define IPI_BITMAP_VECTOR (APIC_IPI_INTS + 6)
/* IPIs handled by IPI_BITMAPED_VECTOR (XXX ups is there a better place?) */
#define IPI_AST 0 /* Generate software trap. */
#define IPI_PREEMPT 1
#define IPI_HARDCLOCK 2
#define IPI_BITMAP_LAST IPI_HARDCLOCK
#define IPI_IS_BITMAPED(x) ((x) <= IPI_BITMAP_LAST)
#define IPI_STOP (APIC_IPI_INTS + 7) /* Stop CPU until restarted. */
#define IPI_SUSPEND (APIC_IPI_INTS + 8) /* Suspend CPU until restarted. */
#define IPI_STOP_HARD (APIC_IPI_INTS + 9) /* Stop CPU with a NMI. */
/*
* The spurious interrupt can share the priority class with the IPIs since
* it is not a normal interrupt. (Does not use the APIC's interrupt fifo)
*/
#define APIC_SPURIOUS_INT 255
#define LVT_LINT0 0
#define LVT_LINT1 1
#define LVT_TIMER 2
#define LVT_ERROR 3
#define LVT_PMC 4
#define LVT_THERMAL 5
#define LVT_CMCI 6
#define LVT_MAX LVT_CMCI
#ifndef LOCORE
#define APIC_IPI_DEST_SELF -1
#define APIC_IPI_DEST_ALL -2
#define APIC_IPI_DEST_OTHERS -3
#define APIC_BUS_UNKNOWN -1
#define APIC_BUS_ISA 0
#define APIC_BUS_EISA 1
#define APIC_BUS_PCI 2
#define APIC_BUS_MAX APIC_BUS_PCI
/*
* An APIC enumerator is a psuedo bus driver that enumerates APIC's including
* CPU's and I/O APIC's.
*/
struct apic_enumerator {
const char *apic_name;
int (*apic_probe)(void);
int (*apic_probe_cpus)(void);
int (*apic_setup_local)(void);
int (*apic_setup_io)(void);
SLIST_ENTRY(apic_enumerator) apic_next;
};
inthand_t
IDTVEC(apic_isr1), IDTVEC(apic_isr2), IDTVEC(apic_isr3),
IDTVEC(apic_isr4), IDTVEC(apic_isr5), IDTVEC(apic_isr6),
IDTVEC(apic_isr7), IDTVEC(cmcint), IDTVEC(errorint),
IDTVEC(spuriousint), IDTVEC(timerint);
extern vm_paddr_t lapic_paddr;
extern int apic_cpuids[];
u_int apic_alloc_vector(u_int apic_id, u_int irq);
u_int apic_alloc_vectors(u_int apic_id, u_int *irqs, u_int count,
u_int align);
void apic_disable_vector(u_int apic_id, u_int vector);
void apic_enable_vector(u_int apic_id, u_int vector);
void apic_free_vector(u_int apic_id, u_int vector, u_int irq);
u_int apic_idt_to_irq(u_int apic_id, u_int vector);
void apic_register_enumerator(struct apic_enumerator *enumerator);
u_int apic_cpuid(u_int apic_id);
void *ioapic_create(vm_paddr_t addr, int32_t apic_id, int intbase);
int ioapic_disable_pin(void *cookie, u_int pin);
int ioapic_get_vector(void *cookie, u_int pin);
void ioapic_register(void *cookie);
int ioapic_remap_vector(void *cookie, u_int pin, int vector);
int ioapic_set_bus(void *cookie, u_int pin, int bus_type);
int ioapic_set_extint(void *cookie, u_int pin);
int ioapic_set_nmi(void *cookie, u_int pin);
int ioapic_set_polarity(void *cookie, u_int pin, enum intr_polarity pol);
int ioapic_set_triggermode(void *cookie, u_int pin,
enum intr_trigger trigger);
int ioapic_set_smi(void *cookie, u_int pin);
void lapic_create(u_int apic_id, int boot_cpu);
void lapic_disable(void);
void lapic_disable_pmc(void);
void lapic_dump(const char *str);
void lapic_enable_cmc(void);
int lapic_enable_pmc(void);
void lapic_eoi(void);
int lapic_id(void);
void lapic_init(vm_paddr_t addr);
int lapic_intr_pending(u_int vector);
void lapic_ipi_raw(register_t icrlo, u_int dest);
void lapic_ipi_vectored(u_int vector, int dest);
int lapic_ipi_wait(int delay);
void lapic_handle_cmc(void);
void lapic_handle_error(void);
void lapic_handle_intr(int vector, struct trapframe *frame);
void lapic_handle_timer(struct trapframe *frame);
void lapic_reenable_pmc(void);
void lapic_set_logical_id(u_int apic_id, u_int cluster, u_int cluster_id);
int lapic_set_lvt_mask(u_int apic_id, u_int lvt, u_char masked);
int lapic_set_lvt_mode(u_int apic_id, u_int lvt, u_int32_t mode);
int lapic_set_lvt_polarity(u_int apic_id, u_int lvt,
enum intr_polarity pol);
int lapic_set_lvt_triggermode(u_int apic_id, u_int lvt,
enum intr_trigger trigger);
void lapic_set_tpr(u_int vector);
void lapic_setup(int boot);
#endif /* !LOCORE */
#endif /* _MACHINE_APICVAR_H_ */
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