From 36d632ea831fd2fa3cb62599a465825f59076f64 Mon Sep 17 00:00:00 2001

From: Nicholas Piggin <npiggin@gmail.com>

Date: Sat, 5 May 2018 03:19:29 +1000

Subject: [PATCH] powerpc/64: remove start_tb and accum_tb from thread_struct

References: bsc#1186487 ltc#177613

Patch-mainline: v4.18-rc1

Git-commit: 36d632ea831fd2fa3cb62599a465825f59076f64

These fields are only written to.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Acked-by: Michal Suchanek <msuchanek@suse.de>

---

 arch/powerpc/include/asm/processor.h | 4 ----

 arch/powerpc/kernel/process.c        | 6 +-----

 2 files changed, 1 insertion(+), 9 deletions(-)

diff --git a/arch/powerpc/include/asm/processor.h b/arch/powerpc/include/asm/processor.h

index c4b36a494a63..eff269adfa71 100644

--- a/arch/powerpc/include/asm/processor.h

+++ b/arch/powerpc/include/asm/processor.h

@@ -264,10 +264,6 @@ struct thread_struct {

 	struct thread_fp_state	*fp_save_area;

 	int		fpexc_mode;	/* floating-point exception mode */

 	unsigned int	align_ctl;	/* alignment handling control */

-#ifdef CONFIG_PPC64

-	unsigned long	start_tb;	/* Start purr when proc switched in */

-	unsigned long	accum_tb;	/* Total accumulated purr for process */

-#endif

 #ifdef CONFIG_HAVE_HW_BREAKPOINT

 	struct perf_event *ptrace_bps[HBP_NUM];

 	/*

diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c

index 25db000fa5b3..f4e5291584c5 100644

--- a/arch/powerpc/kernel/process.c

+++ b/arch/powerpc/kernel/process.c

@@ -1188,11 +1188,7 @@ struct task_struct *__switch_to(struct task_struct *prev,

 	 */

 	if (firmware_has_feature(FW_FEATURE_SPLPAR)) {

 		struct cpu_usage *cu = this_cpu_ptr(&cpu_usage_array);

-		long unsigned start_tb, current_tb;

-		start_tb = old_thread->start_tb;

-		cu->current_tb = current_tb = mfspr(SPRN_PURR);

-		old_thread->accum_tb += (current_tb - start_tb);

-		new_thread->start_tb = current_tb;

+		cu->current_tb = mfspr(SPRN_PURR);

 	}

 #endif /* CONFIG_PPC64 */

-- 

2.26.2