From 2ff2d3d74705d34ab71b21f54634fcf50d57bdd5 Mon Sep 17 00:00:00 2001 From: Stephane Eranian Date: Tue, 13 Feb 2007 13:26:22 +0100 Subject: [PATCH] i386: add idle notifier Add a notifier mechanism to the low level idle loop. You can register a callback function which gets invoked on entry and exit from the low level idle loop. The low level idle loop is defined as the polling loop, low-power call, or the mwait instruction. Interrupts processed by the idle thread are not considered part of the low level loop. The notifier can be used to measure precisely how much is spent in useless execution (or low power mode). The perfmon subsystem uses it to turn on/off monitoring. Signed-off-by: stephane eranian Signed-off-by: Andrew Morton Signed-off-by: Andi Kleen --- arch/i386/kernel/irq.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'arch/i386/kernel/irq.c') diff --git a/arch/i386/kernel/irq.c b/arch/i386/kernel/irq.c index 3201d421090a..5785d84103a6 100644 --- a/arch/i386/kernel/irq.c +++ b/arch/i386/kernel/irq.c @@ -19,6 +19,8 @@ #include #include +#include + DEFINE_PER_CPU(irq_cpustat_t, irq_stat) ____cacheline_internodealigned_in_smp; EXPORT_PER_CPU_SYMBOL(irq_stat); @@ -61,6 +63,7 @@ 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", -- cgit v1.2.2 From e05d723f98595b2f4d368f63636a997d98703304 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Fri, 16 Feb 2007 01:27:58 -0800 Subject: [PATCH] i386, apic: clean up the APIC code The apic code is quite unstructured and missing a lot of comments. - Restructure the code into helper functions, timer, setup/shutdown, interrupt and power management blocks. - Fixup comments. - Namespace fixups - Inline helpers for version and is_integrated - Combine the ack_bad_irq functions No functional changes. Signed-off-by: Thomas Gleixner Signed-off-by: Ingo Molnar Cc: Zachary Amsden Cc: "Eric W. Biederman" Cc: Rohit Seth Cc: Andi Kleen Cc: john stultz Cc: Roman Zippel Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/i386/kernel/irq.c | 22 ++++++++++++++++++---- 1 file changed, 18 insertions(+), 4 deletions(-) (limited to 'arch/i386/kernel/irq.c') diff --git a/arch/i386/kernel/irq.c b/arch/i386/kernel/irq.c index 5785d84103a6..0f2ca590bf23 100644 --- a/arch/i386/kernel/irq.c +++ b/arch/i386/kernel/irq.c @@ -10,7 +10,6 @@ * io_apic.c.) */ -#include #include #include #include @@ -21,19 +20,34 @@ #include +#include +#include + DEFINE_PER_CPU(irq_cpustat_t, irq_stat) ____cacheline_internodealigned_in_smp; EXPORT_PER_CPU_SYMBOL(irq_stat); -#ifndef CONFIG_X86_LOCAL_APIC /* * 'what should we do if we get a hw irq event on an illegal vector'. * each architecture has to answer this themselves. */ void ack_bad_irq(unsigned int irq) { - printk("unexpected IRQ trap at vector %02x\n", irq); -} + printk(KERN_ERR "unexpected IRQ trap at vector %02x\n", irq); + +#ifdef CONFIG_X86_LOCAL_APIC + /* + * Currently unexpected vectors happen only on SMP and APIC. + * We _must_ ack these because every local APIC has only N + * irq slots per priority level, and a 'hanging, unacked' IRQ + * holds up an irq slot - in excessive cases (when multiple + * unexpected vectors occur) that might lock up the APIC + * completely. + * But only ack when the APIC is enabled -AK + */ + if (cpu_has_apic) + ack_APIC_irq(); #endif +} #ifdef CONFIG_4KSTACKS /* -- cgit v1.2.2