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authorLinus Torvalds <torvalds@woody.linux-foundation.org>2007-02-26 09:21:46 -0800
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-02-26 09:21:46 -0800
commitea3d5226f52ef30f52aa0a04f47f5919c7facacf (patch)
tree090a48a6f6b2934d32a641ec6e61b3dc59a48514 /arch
parent9654640d0af8f2de40ff3807d3695109d3463f54 (diff)
Revert "[PATCH] i386: add idle notifier"
This reverts commit 2ff2d3d74705d34ab71b21f54634fcf50d57bdd5. Uwe Bugla reports that he cannot mount a floppy drive any more, and Jiri Slaby bisected it down to this commit. Benjamin LaHaise also points out that this is a big hot-path, and that interrupt delivery while idle is very common and should not go through all these expensive gyrations. Fix up conflicts in arch/i386/kernel/apic.c and arch/i386/kernel/irq.c due to other unrelated irq changes. Cc: Stephane Eranian <eranian@hpl.hp.com> Cc: Andi Kleen <ak@suse.de> Cc: Andrew Morton <akpm@osdl.org> Cc: Uwe Bugla <uwe.bugla@gmx.de> Cc: Jiri Slaby <jirislaby@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch')
-rw-r--r--arch/i386/kernel/apic.c4
-rw-r--r--arch/i386/kernel/cpu/mcheck/p4.c2
-rw-r--r--arch/i386/kernel/irq.c3
-rw-r--r--arch/i386/kernel/process.c53
-rw-r--r--arch/i386/kernel/smp.c2
5 files changed, 1 insertions, 63 deletions
diff --git a/arch/i386/kernel/apic.c b/arch/i386/kernel/apic.c
index 9655c233e6f..7a2c9cbdb51 100644
--- a/arch/i386/kernel/apic.c
+++ b/arch/i386/kernel/apic.c
@@ -38,7 +38,6 @@
#include <asm/hpet.h>
#include <asm/i8253.h>
#include <asm/nmi.h>
-#include <asm/idle.h>
#include <mach_apic.h>
#include <mach_apicdef.h>
@@ -561,7 +560,6 @@ void fastcall smp_apic_timer_interrupt(struct pt_regs *regs)
* Besides, if we don't timer interrupts ignore the global
* interrupt lock, which is the WrongThing (tm) to do.
*/
- exit_idle();
irq_enter();
local_apic_timer_interrupt();
irq_exit();
@@ -1221,7 +1219,6 @@ void smp_spurious_interrupt(struct pt_regs *regs)
{
unsigned long v;
- exit_idle();
irq_enter();
/*
* Check if this really is a spurious interrupt and ACK it
@@ -1245,7 +1242,6 @@ void smp_error_interrupt(struct pt_regs *regs)
{
unsigned long v, v1;
- exit_idle();
irq_enter();
/* First tickle the hardware, only then report what went on. -- REW */
v = apic_read(APIC_ESR);
diff --git a/arch/i386/kernel/cpu/mcheck/p4.c b/arch/i386/kernel/cpu/mcheck/p4.c
index 8359c19d3a2..504434a4601 100644
--- a/arch/i386/kernel/cpu/mcheck/p4.c
+++ b/arch/i386/kernel/cpu/mcheck/p4.c
@@ -12,7 +12,6 @@
#include <asm/system.h>
#include <asm/msr.h>
#include <asm/apic.h>
-#include <asm/idle.h>
#include <asm/therm_throt.h>
@@ -60,7 +59,6 @@ static void (*vendor_thermal_interrupt)(struct pt_regs *regs) = unexpected_therm
fastcall void smp_thermal_interrupt(struct pt_regs *regs)
{
- exit_idle();
irq_enter();
vendor_thermal_interrupt(regs);
irq_exit();
diff --git a/arch/i386/kernel/irq.c b/arch/i386/kernel/irq.c
index 0f2ca590bf2..8db8d514c9c 100644
--- a/arch/i386/kernel/irq.c
+++ b/arch/i386/kernel/irq.c
@@ -18,8 +18,6 @@
#include <linux/cpu.h>
#include <linux/delay.h>
-#include <asm/idle.h>
-
#include <asm/apic.h>
#include <asm/uaccess.h>
@@ -77,7 +75,6 @@ fastcall unsigned int do_IRQ(struct pt_regs *regs)
union irq_ctx *curctx, *irqctx;
u32 *isp;
#endif
- exit_idle();
if (unlikely((unsigned)irq >= NR_IRQS)) {
printk(KERN_EMERG "%s: cannot handle IRQ %d\n",
diff --git a/arch/i386/kernel/process.c b/arch/i386/kernel/process.c
index bea304d48cd..393a67d5d94 100644
--- a/arch/i386/kernel/process.c
+++ b/arch/i386/kernel/process.c
@@ -49,7 +49,6 @@
#include <asm/i387.h>
#include <asm/desc.h>
#include <asm/vm86.h>
-#include <asm/idle.h>
#ifdef CONFIG_MATH_EMULATION
#include <asm/math_emu.h>
#endif
@@ -82,42 +81,6 @@ void (*pm_idle)(void);
EXPORT_SYMBOL(pm_idle);
static DEFINE_PER_CPU(unsigned int, cpu_idle_state);
-static ATOMIC_NOTIFIER_HEAD(idle_notifier);
-
-void idle_notifier_register(struct notifier_block *n)
-{
- atomic_notifier_chain_register(&idle_notifier, n);
-}
-
-void idle_notifier_unregister(struct notifier_block *n)
-{
- atomic_notifier_chain_unregister(&idle_notifier, n);
-}
-
-static DEFINE_PER_CPU(volatile unsigned long, idle_state);
-
-void enter_idle(void)
-{
- /* needs to be atomic w.r.t. interrupts, not against other CPUs */
- __set_bit(0, &__get_cpu_var(idle_state));
- atomic_notifier_call_chain(&idle_notifier, IDLE_START, NULL);
-}
-
-static void __exit_idle(void)
-{
- /* needs to be atomic w.r.t. interrupts, not against other CPUs */
- if (__test_and_clear_bit(0, &__get_cpu_var(idle_state)) == 0)
- return;
- atomic_notifier_call_chain(&idle_notifier, IDLE_END, NULL);
-}
-
-void exit_idle(void)
-{
- if (current->pid)
- return;
- __exit_idle();
-}
-
void disable_hlt(void)
{
hlt_counter++;
@@ -168,7 +131,6 @@ EXPORT_SYMBOL(default_idle);
*/
static void poll_idle (void)
{
- local_irq_enable();
cpu_relax();
}
@@ -229,16 +191,7 @@ void cpu_idle(void)
play_dead();
__get_cpu_var(irq_stat).idle_timestamp = jiffies;
-
- /*
- * Idle routines should keep interrupts disabled
- * from here on, until they go to idle.
- * Otherwise, idle callbacks can misfire.
- */
- local_irq_disable();
- enter_idle();
idle();
- __exit_idle();
}
tick_nohz_restart_sched_tick();
preempt_enable_no_resched();
@@ -293,11 +246,7 @@ void mwait_idle_with_hints(unsigned long eax, unsigned long ecx)
__monitor((void *)&current_thread_info()->flags, 0, 0);
smp_mb();
if (!need_resched())
- __sti_mwait(eax, ecx);
- else
- local_irq_enable();
- } else {
- local_irq_enable();
+ __mwait(eax, ecx);
}
}
diff --git a/arch/i386/kernel/smp.c b/arch/i386/kernel/smp.c
index 9bd9637ae69..0e8977871b1 100644
--- a/arch/i386/kernel/smp.c
+++ b/arch/i386/kernel/smp.c
@@ -23,7 +23,6 @@
#include <asm/mtrr.h>
#include <asm/tlbflush.h>
-#include <asm/idle.h>
#include <mach_apic.h>
/*
@@ -624,7 +623,6 @@ fastcall void smp_call_function_interrupt(struct pt_regs *regs)
/*
* At this point the info structure may be out of scope unless wait==1
*/
- exit_idle();
irq_enter();
(*func)(info);
irq_exit();