Revert "x86: fix ioapic bug again"

This reverts commit 6e908947b4995bc0e551a8257c586d5c3e428201.

Németh Márton reported:

| there is a problem in 2.6.26-rc3 which was not there in case of
| 2.6.25: the CPU wakes up ~90,000 times per sec instead of ~60 per sec.
|
| I also "git bisected" the problem, the result is:
|
| 6e908947b4995bc0e551a8257c586d5c3e428201 is first bad commit
| commit 6e908947b4995bc0e551a8257c586d5c3e428201
| Author: Ingo Molnar <mingo@elte.hu>
| Date:   Fri Mar 21 14:32:36 2008 +0100
|
|     x86: fix ioapic bug again

the original problem is fixed by Maciej W. Rozycki in the tip/x86/apic
branch (confirmed by Márton), but those changes are too intrusive for
v2.6.26 so we'll go for the less intrusive (repeated) revert now.

Reported-and-bisected-by: Németh Márton <nm127@freemail.hu>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

diff --git a/arch/x86/kernel/io_apic_32.c b/arch/x86/kernel/io_apic_32.c
index a40d54fc1fdd819125a1d7b609566180062b6ecc..4dc8600d9d2072ed5ed79ee3884f70afd2281636 100644 (file)
--- a/arch/x86/kernel/io_apic_32.c
+++ b/arch/x86/kernel/io_apic_32.c
@@ -2130,14 +2130,10 @@ static inline void __init check_timer(void)
 {
        int apic1, pin1, apic2, pin2;
        int vector;
-       unsigned int ver;
        unsigned long flags;
 
        local_irq_save(flags);
 
-       ver = apic_read(APIC_LVR);
-       ver = GET_APIC_VERSION(ver);
-
        /*
         * get/set the timer IRQ vector:
         */
@@ -2150,15 +2146,11 @@ static inline void __init check_timer(void)
         * mode for the 8259A whenever interrupts are routed
         * through I/O APICs.  Also IRQ0 has to be enabled in
         * the 8259A which implies the virtual wire has to be
-        * disabled in the local APIC.  Finally timer interrupts
-        * need to be acknowledged manually in the 8259A for
-        * timer_interrupt() and for the i82489DX when using
-        * the NMI watchdog.
+        * disabled in the local APIC.
         */
        apic_write_around(APIC_LVT0, APIC_LVT_MASKED | APIC_DM_EXTINT);
        init_8259A(1);
-       timer_ack = !cpu_has_tsc;
-       timer_ack |= (nmi_watchdog == NMI_IO_APIC && !APIC_INTEGRATED(ver));
+       timer_ack = 1;
        if (timer_over_8254 > 0)
                enable_8259A_irq(0);
 

diff --git a/arch/x86/kernel/nmi_32.c b/arch/x86/kernel/nmi_32.c
index 11b14bbaa61e6be6cfb1ffe7fd5b4c8f69fd71a7..84160f74eeb0abadbb9bcbffaef9e19ba58164a6 100644 (file)
--- a/arch/x86/kernel/nmi_32.c
+++ b/arch/x86/kernel/nmi_32.c
@@ -26,7 +26,6 @@
 
 #include <asm/smp.h>
 #include <asm/nmi.h>
-#include <asm/timer.h>
 
 #include "mach_traps.h"
 
@@ -82,7 +81,7 @@ int __init check_nmi_watchdog(void)
 
        prev_nmi_count = kmalloc(NR_CPUS * sizeof(int), GFP_KERNEL);
        if (!prev_nmi_count)
-               goto error;
+               return -1;
 
        printk(KERN_INFO "Testing NMI watchdog ... ");
 
@@ -119,7 +118,7 @@ int __init check_nmi_watchdog(void)
        if (!atomic_read(&nmi_active)) {
                kfree(prev_nmi_count);
                atomic_set(&nmi_active, -1);
-               goto error;
+               return -1;
        }
        printk("OK.\n");
 
@@ -130,10 +129,6 @@ int __init check_nmi_watchdog(void)
 
        kfree(prev_nmi_count);
        return 0;
-error:
-       timer_ack = !cpu_has_tsc;
-
-       return -1;
 }
 
 static int __init setup_nmi_watchdog(char *str)