[PATCH 2/2] ARM: Enable tracing around vfp preemption enable/disable

Stephen Boyd
2013-03-04T22:43:10Z

The VFP code enables and disables preemption but doesn't call
into the tracer except for in the VFP bounce code to say that
preemption has been enabled again. Trace the preemption disable
and enable calls made in assembly so that we can accurately
measure how long preemption is disabled while handling VFP
exceptions.

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
---
arch/arm/kernel/entry-header.S | 14 ++++++++++++++
1 file changed, 14 insertions(+)

diff --git a/arch/arm/kernel/entry-header.S b/arch/arm/kernel/entry-header.S
index 130e6a6..75bcb18 100644
--- a/arch/arm/kernel/entry-header.S
+++ b/arch/arm/kernel/entry-header.S
@@ -165,19 +165,33 @@

.macro preempt_enable_no_resched, tsk, cnt
#ifdef CONFIG_PREEMPT_COUNT
+#if defined(CONFIG_DEBUG_PREEMPT) || defined(CONFIG_PREEMPT_TRACER)
+ stmdb sp!, {r0-r3, ip, lr}
+ mov r0, #1
+ bl sub_preempt_count
+ ldmia sp!, {r0-r3, ip, lr}
+#else
get_thread_info \tsk
ldr \cnt, [\tsk, #TI_PREEMPT] @ get preempt count
sub \cnt, \cnt, #1 @ decrement it
str \cnt, [\tsk, #TI_PREEMPT]
#endif
+#endif
.endm

.macro preempt_disable, tsk, cnt
#ifdef CONFIG_PREEMPT_COUNT
+#if defined(CONFIG_DEBUG_PREEMPT) || defined(CONFIG_PREEMPT_TRACER)
+ stmdb sp!, {r0-r3, ip, lr}
+ mov r0, #1
+ bl add_preempt_count
+ ldmia sp!, {r0-r3, ip, lr}
+#else
ldr \cnt, [\tsk, #TI_PREEMPT] @ get preempt count
add \cnt, \cnt, #1 @ increment it
str \cnt, [\tsk, #TI_PREEMPT]
#endif
+#endif
.endm

/*