kernel_optimize_test/arch/i386/mach-default/setup.c
Ashok Raj 67664c8f7e [PATCH] i386: Dont use IPI broadcast when using cpu hotplug.
This patch introduces a startup parameter no_broadcast.  When we enable
CONFIG_HOTPLUG_CPU, we dont want to use broadcast shortcut as it has ill
effects on a offline cpu.  If we issue broadcast, the IPI is also delivered
to offline cpus, or partially up cpu causing stale IPI's to be handled,
which is a problem and can cause undesirable effects.

Introduces a new startup cmdline option no_ipi_broadcast, that can be
switched at cmdline if necessary.

Signed-off-by: Ashok Raj <ashok.raj@intel.com>
Acked-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-25 16:24:29 -07:00

134 lines
3.1 KiB
C

/*
* Machine specific setup for generic
*/
#include <linux/config.h>
#include <linux/smp.h>
#include <linux/init.h>
#include <linux/irq.h>
#include <linux/interrupt.h>
#include <asm/acpi.h>
#include <asm/arch_hooks.h>
#ifdef CONFIG_HOTPLUG_CPU
#define DEFAULT_SEND_IPI (1)
#else
#define DEFAULT_SEND_IPI (0)
#endif
int no_broadcast=DEFAULT_SEND_IPI;
/**
* pre_intr_init_hook - initialisation prior to setting up interrupt vectors
*
* Description:
* Perform any necessary interrupt initialisation prior to setting up
* the "ordinary" interrupt call gates. For legacy reasons, the ISA
* interrupts should be initialised here if the machine emulates a PC
* in any way.
**/
void __init pre_intr_init_hook(void)
{
init_ISA_irqs();
}
/*
* IRQ2 is cascade interrupt to second interrupt controller
*/
static struct irqaction irq2 = { no_action, 0, CPU_MASK_NONE, "cascade", NULL, NULL};
/**
* intr_init_hook - post gate setup interrupt initialisation
*
* Description:
* Fill in any interrupts that may have been left out by the general
* init_IRQ() routine. interrupts having to do with the machine rather
* than the devices on the I/O bus (like APIC interrupts in intel MP
* systems) are started here.
**/
void __init intr_init_hook(void)
{
#ifdef CONFIG_X86_LOCAL_APIC
apic_intr_init();
#endif
if (!acpi_ioapic)
setup_irq(2, &irq2);
}
/**
* pre_setup_arch_hook - hook called prior to any setup_arch() execution
*
* Description:
* generally used to activate any machine specific identification
* routines that may be needed before setup_arch() runs. On VISWS
* this is used to get the board revision and type.
**/
void __init pre_setup_arch_hook(void)
{
}
/**
* trap_init_hook - initialise system specific traps
*
* Description:
* Called as the final act of trap_init(). Used in VISWS to initialise
* the various board specific APIC traps.
**/
void __init trap_init_hook(void)
{
}
static struct irqaction irq0 = { timer_interrupt, SA_INTERRUPT, CPU_MASK_NONE, "timer", NULL, NULL};
/**
* time_init_hook - do any specific initialisations for the system timer.
*
* Description:
* Must plug the system timer interrupt source at HZ into the IRQ listed
* in irq_vectors.h:TIMER_IRQ
**/
void __init time_init_hook(void)
{
setup_irq(0, &irq0);
}
#ifdef CONFIG_MCA
/**
* mca_nmi_hook - hook into MCA specific NMI chain
*
* Description:
* The MCA (Microchannel Arcitecture) has an NMI chain for NMI sources
* along the MCA bus. Use this to hook into that chain if you will need
* it.
**/
void __init mca_nmi_hook(void)
{
/* If I recall correctly, there's a whole bunch of other things that
* we can do to check for NMI problems, but that's all I know about
* at the moment.
*/
printk("NMI generated from unknown source!\n");
}
#endif
static __init int no_ipi_broadcast(char *str)
{
get_option(&str, &no_broadcast);
printk ("Using %s mode\n", no_broadcast ? "No IPI Broadcast" :
"IPI Broadcast");
return 1;
}
__setup("no_ipi_broadcast", no_ipi_broadcast);
static int __init print_ipi_mode(void)
{
printk ("Using IPI %s mode\n", no_broadcast ? "No-Shortcut" :
"Shortcut");
return 0;
}
late_initcall(print_ipi_mode);