xen/53f7386d-x86-irq-process-softirqs-in-irq-keyhandlers.patch

# Commit e13b3203990706db1313ec2aadd9a30b249ee793
# Date 2014-08-22 14:32:45 +0200
# Author Andrew Cooper <andrew.cooper3@citrix.com>
# Committer Jan Beulich <jbeulich@suse.com>
x86/irq: process softirqs in irq keyhandlers

Large machines with lots of interrupts can trip over the Xen watchdog.

Suggested-by: Santosh Jodh <Santosh.Jodh@citrix.com>
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Tested-by: Santosh Jodh <Santosh.Jodh@citrix.com>

# Commit bd083922f9e78ed19ef98e7de372e5f568402ed3
# Date 2014-08-26 17:56:52 +0200
# Author Jan Beulich <jbeulich@suse.com>
# Committer Jan Beulich <jbeulich@suse.com>
x86/IO-APIC: don't process softirqs during early boot

Commit e13b320399 ("x86/irq: process softirqs in irq keyhandlers")
made this unconditional, but the boot time use of __print_IO_APIC()
(when "apic_verbosity=debug" was given) can't tolerate that.

Reported-by: Sander Eikelenboom <linux@eikelenboom.it>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Tested-by:  Sander Eikelenboom <linux@eikelenboom.it>

--- a/xen/arch/x86/io_apic.c
+++ b/xen/arch/x86/io_apic.c
@@ -28,6 +28,7 @@
 #include <xen/sched.h>
 #include <xen/acpi.h>
 #include <xen/keyhandler.h>
+#include <xen/softirq.h>
 #include <asm/mc146818rtc.h>
 #include <asm/smp.h>
 #include <asm/desc.h>
@@ -1091,7 +1092,7 @@ static inline void UNEXPECTED_IO_APIC(vo
 {
 }
 
-static void /*__init*/ __print_IO_APIC(void)
+static void /*__init*/ __print_IO_APIC(bool_t boot)
 {
     int apic, i;
     union IO_APIC_reg_00 reg_00;
@@ -1112,6 +1113,9 @@ static void /*__init*/ __print_IO_APIC(v
     printk(KERN_INFO "testing the IO APIC.......................\n");
 
     for (apic = 0; apic < nr_ioapics; apic++) {
+        if ( !boot )
+            process_pending_softirqs();
+
         if (!nr_ioapic_entries[apic])
             continue;
 
@@ -1215,6 +1219,10 @@ static void /*__init*/ __print_IO_APIC(v
     printk(KERN_DEBUG "IRQ to pin mappings:\n");
     for (i = 0; i < nr_irqs_gsi; i++) {
         struct irq_pin_list *entry = irq_2_pin + i;
+
+        if ( !boot && !(i & 0x1f) )
+            process_pending_softirqs();
+
         if (entry->pin < 0)
             continue;
         printk(KERN_DEBUG "IRQ%d ", irq_to_desc(i)->arch.vector);
@@ -1235,12 +1243,12 @@ static void /*__init*/ __print_IO_APIC(v
 static void __init print_IO_APIC(void)
 {
     if (apic_verbosity != APIC_QUIET)
-        __print_IO_APIC();
+        __print_IO_APIC(1);
 }
 
 static void _print_IO_APIC_keyhandler(unsigned char key)
 {
-    __print_IO_APIC();
+    __print_IO_APIC(0);
 }
 static struct keyhandler print_IO_APIC_keyhandler = {
     .diagnostic = 1,
@@ -2454,6 +2462,9 @@ void dump_ioapic_irq_info(void)
 
     for ( irq = 0; irq < nr_irqs_gsi; irq++ )
     {
+        if ( !(irq & 0x1f) )
+            process_pending_softirqs();
+
         entry = &irq_2_pin[irq];
         if ( entry->pin == -1 )
             continue;
--- a/xen/arch/x86/irq.c
+++ b/xen/arch/x86/irq.c
@@ -19,6 +19,7 @@
 #include <xen/iommu.h>
 #include <xen/symbols.h>
 #include <xen/trace.h>
+#include <xen/softirq.h>
 #include <xsm/xsm.h>
 #include <asm/msi.h>
 #include <asm/current.h>
@@ -2231,6 +2232,8 @@ static void dump_irqs(unsigned char key)
 
     for ( irq = 0; irq < nr_irqs; irq++ )
     {
+        if ( !(irq & 0x1f) )
+            process_pending_softirqs();
 
         desc = irq_to_desc(irq);
 
@@ -2284,6 +2287,7 @@ static void dump_irqs(unsigned char key)
         xfree(ssid);
     }
 
+    process_pending_softirqs();
     printk("Direct vector information:\n");
     for ( i = FIRST_DYNAMIC_VECTOR; i < NR_VECTORS; ++i )
         if ( direct_apic_vector[i] )