[PATCH] x86_64: Reduce screen space needed by stack trace
Especially under Xen, where the console cannot be adjusted to more than 25
lines, it is fairly important that the information displayed during a panic
is as compact as possible. Below adjustments work towards that.
Signed-Off-By: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/arch/x86_64/kernel/traps.c b/arch/x86_64/kernel/traps.c
index fcee07d..d345c71 100644
--- a/arch/x86_64/kernel/traps.c
+++ b/arch/x86_64/kernel/traps.c
@@ -183,7 +183,6 @@
void show_trace(unsigned long *stack)
{
- unsigned long addr;
const unsigned cpu = safe_smp_processor_id();
unsigned long *irqstack_end = (unsigned long *)cpu_pda(cpu)->irqstackptr;
int i;
@@ -193,8 +192,14 @@
#define HANDLE_STACK(cond) \
do while (cond) { \
- addr = *stack++; \
+ unsigned long addr = *stack++; \
if (kernel_text_address(addr)) { \
+ if (i > 50) { \
+ printk("\n "); \
+ i = 0; \
+ } \
+ else \
+ i += printk(" "); \
/* \
* If the address is either in the text segment of the \
* kernel, or in the region which contains vmalloc'ed \
@@ -204,25 +209,19 @@
* out the call path that was taken. \
*/ \
i += printk_address(addr); \
- if (i > 50) { \
- printk("\n "); \
- i = 0; \
- } \
- else \
- i += printk(" "); \
} \
} while (0)
- for(i = 0; ; ) {
+ for(i = 11; ; ) {
const char *id;
unsigned long *estack_end;
estack_end = in_exception_stack(cpu, (unsigned long)stack,
&used, &id);
if (estack_end) {
- i += printk(" <%s> ", id);
+ i += printk(" <%s>", id);
HANDLE_STACK (stack < estack_end);
- i += printk(" <EOE> ");
+ i += printk(" <EOE>");
stack = (unsigned long *) estack_end[-2];
continue;
}
@@ -232,11 +231,11 @@
(IRQSTACKSIZE - 64) / sizeof(*irqstack);
if (stack >= irqstack && stack < irqstack_end) {
- i += printk(" <IRQ> ");
+ i += printk(" <IRQ>");
HANDLE_STACK (stack < irqstack_end);
stack = (unsigned long *) (irqstack_end[-1]);
irqstack_end = NULL;
- i += printk(" <EOI> ");
+ i += printk(" <EOI>");
continue;
}
}