On large systems, dumping state may cause time management to get
stalled for so long a period that it wouldn't recover. Therefore alter
the state dumping logic to
- block each CPU as it prints rather than one CPU for a very long time
- don't print useless data (e.g. the hypervisor context of the
interrupt that is used for triggering the printing, but isn't part
of the context that's actuall interesting.
Signed-off-by: Jan Beulich <jbeulich@xxxxxxxxxx>
--- 2010-05-04.orig/xen/arch/ia64/linux-xen/smp.c 2009-05-27
13:54:05.000000000 +0200
+++ 2010-05-04/xen/arch/ia64/linux-xen/smp.c 2010-05-04 13:22:27.000000000
+0200
@@ -189,7 +189,7 @@ handle_IPI (int irq, void *dev_id, struc
* At this point the structure may be
gone unless
* wait is true.
*/
- (*func)(info);
+ (*func)(info ?: regs);
/* Notify the sending CPU that the task
is done. */
mb();
--- 2010-05-04.orig/xen/arch/x86/smp.c 2010-04-22 14:43:25.000000000 +0200
+++ 2010-05-04/xen/arch/x86/smp.c 2010-05-04 13:22:27.000000000 +0200
@@ -395,7 +395,7 @@ static void __smp_call_function_interrup
if ( call_data.wait )
{
- (*func)(info);
+ (*func)(info ?: get_irq_regs());
mb();
atomic_inc(&call_data.finished);
}
@@ -403,7 +403,7 @@ static void __smp_call_function_interrup
{
mb();
atomic_inc(&call_data.started);
- (*func)(info);
+ (*func)(info ?: get_irq_regs());
}
irq_exit();
--- 2010-05-04.orig/xen/common/keyhandler.c 2010-05-04 13:21:53.000000000
+0200
+++ 2010-05-04/xen/common/keyhandler.c 2010-05-04 13:22:27.000000000 +0200
@@ -71,20 +71,45 @@ static struct keyhandler show_handlers_k
.desc = "show this message"
};
-static void __dump_execstate(void *unused)
+static cpumask_t dump_execstate_mask;
+
+static void __dump_execstate(void *_regs)
{
- dump_execution_state();
- printk("*** Dumping CPU%d guest state: ***\n", smp_processor_id());
+ struct cpu_user_regs *regs = _regs;
+ unsigned int cpu = smp_processor_id();
+
+ if ( !guest_mode(regs) )
+ {
+ printk("\n*** Dumping CPU%u host state: ***\n", cpu);
+ show_execution_state(regs);
+ }
if ( is_idle_vcpu(current) )
- printk("No guest context (CPU is idle).\n");
+ printk("No guest context (CPU%u is idle).\n", cpu);
else
+ {
+ printk("*** Dumping CPU%u guest state (d%d:v%d): ***\n",
+ smp_processor_id(), current->domain->domain_id,
+ current->vcpu_id);
show_execution_state(guest_cpu_user_regs());
+ }
+
+ cpu = cycle_cpu(cpu, dump_execstate_mask);
+ if ( cpu < NR_CPUS )
+ {
+ cpu_clear(cpu, dump_execstate_mask);
+ on_selected_cpus(cpumask_of(cpu), __dump_execstate, NULL, 0);
+ }
+ else
+ {
+ printk("\n");
+
+ console_end_sync();
+ watchdog_enable();
+ }
}
static void dump_registers(unsigned char key, struct cpu_user_regs *regs)
{
- unsigned int cpu;
-
/* We want to get everything out that we possibly can. */
watchdog_disable();
console_start_sync();
@@ -92,21 +117,9 @@ static void dump_registers(unsigned char
printk("'%c' pressed -> dumping registers\n", key);
/* Get local execution state out immediately, in case we get stuck. */
- printk("\n*** Dumping CPU%d host state: ***\n", smp_processor_id());
- __dump_execstate(NULL);
-
- for_each_online_cpu ( cpu )
- {
- if ( cpu == smp_processor_id() )
- continue;
- printk("\n*** Dumping CPU%d host state: ***\n", cpu);
- on_selected_cpus(cpumask_of(cpu), __dump_execstate, NULL, 1);
- }
-
- printk("\n");
-
- console_end_sync();
- watchdog_enable();
+ cpus_andnot(dump_execstate_mask, cpu_online_map,
+ cpumask_of_cpu(smp_processor_id()));
+ __dump_execstate(regs);
}
static struct keyhandler dump_registers_keyhandler = {
--- 2010-05-04.orig/xen/include/asm-ia64/linux-xen/asm/ptrace.h 2010-04-19
09:12:58.000000000 +0200
+++ 2010-05-04/xen/include/asm-ia64/linux-xen/asm/ptrace.h 2010-05-04
13:22:27.000000000 +0200
@@ -280,7 +280,7 @@ struct switch_stack {
# define ia64_task_regs(t) (((struct pt_regs *) ((char *) (t) +
IA64_STK_OFFSET)) - 1)
# define ia64_psr(regs) ((struct ia64_psr *)
&(regs)->cr_ipsr)
#ifdef XEN
-# define guest_mode(regs) (ia64_psr(regs)->cpl != 0)
+# define guest_mode(regs) (ia64_psr(regs)->cpl &&
!ia64_psr(regs)->vm)
# define guest_kernel_mode(regs) (ia64_psr(regs)->cpl ==
CONFIG_CPL0_EMUL)
# define vmx_guest_kernel_mode(regs) (ia64_psr(regs)->cpl == 0)
# define regs_increment_iip(regs) \
dump-exec-state.patch
Description: Text document
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