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Commit 01f4b8b8 authored by Arnd Bergmann's avatar Arnd Bergmann Committed by Benjamin Herrenschmidt
Browse files

powerpc: support for latencytop 



Implement save_stack_trace_tsk on powerpc, so that we can run with
latencytop.

Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
Signed-off-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
parent 443dcac4

arch/powerpc/Kconfig

+3 −0
Original line number Diff line number Diff line
@@ -53,6 +53,9 @@ config STACKTRACE_SUPPORT 
	bool

	default y



config HAVE_LATENCYTOP_SUPPORT

	def_bool y



config TRACE_IRQFLAGS_SUPPORT

	bool

	depends on PPC64

arch/powerpc/kernel/stacktrace.c

+27 −10
Original line number Diff line number Diff line
@@ -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 (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 @@ void save_stack_trace(struct stack_trace *trace) 
		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);