powerpc: support for latencytop
Implement save_stack_trace_tsk on powerpc, so that we can run with
latencytop.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index aaf9989..5e21854 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -53,6 +53,9 @@
bool
default y
+config HAVE_LATENCYTOP_SUPPORT
+ def_bool y
+
config TRACE_IRQFLAGS_SUPPORT
bool
depends on PPC64
diff --git a/arch/powerpc/kernel/stacktrace.c b/arch/powerpc/kernel/stacktrace.c
index 9629440..6a4fb00 100644
--- a/arch/powerpc/kernel/stacktrace.c
+++ b/arch/powerpc/kernel/stacktrace.c
@@ -10,33 +10,34 @@
* 2 of the License, or (at your option) any later version.
*/
+#include <linux/module.h>
#include <linux/sched.h>
#include <linux/stacktrace.h>
#include <asm/ptrace.h>
+#include <asm/processor.h>
/*
* Save stack-backtrace addresses into a stack_trace buffer.
*/
-void save_stack_trace(struct stack_trace *trace)
+static void save_context_stack(struct stack_trace *trace, unsigned long sp,
+ struct task_struct *tsk, int savesched)
{
- unsigned long sp;
-
- asm("mr %0,1" : "=r" (sp));
-
for (;;) {
unsigned long *stack = (unsigned long *) sp;
unsigned long newsp, ip;
- if (!validate_sp(sp, current, STACK_FRAME_OVERHEAD))
+ if (!validate_sp(sp, tsk, STACK_FRAME_OVERHEAD))
return;
newsp = stack[0];
ip = stack[STACK_FRAME_LR_SAVE];
- if (!trace->skip)
- trace->entries[trace->nr_entries++] = ip;
- else
- trace->skip--;
+ if (savesched || !in_sched_functions(ip)) {
+ if (!trace->skip)
+ trace->entries[trace->nr_entries++] = ip;
+ else
+ trace->skip--;
+ }
if (trace->nr_entries >= trace->max_entries)
return;
@@ -44,3 +45,19 @@
sp = newsp;
}
}
+
+void save_stack_trace(struct stack_trace *trace)
+{
+ unsigned long sp;
+
+ asm("mr %0,1" : "=r" (sp));
+
+ save_context_stack(trace, sp, current, 1);
+}
+EXPORT_SYMBOL_GPL(save_stack_trace);
+
+void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
+{
+ save_context_stack(trace, tsk->thread.regs->gpr[1], tsk, 0);
+}
+EXPORT_SYMBOL_GPL(save_stack_trace_tsk);