[PATCH 17/17] xxx: instrument

From: Vineet Gupta
Date: Thu Dec 03 2015 - 07:43:07 EST


Signed-off-by: Vineet Gupta <vgupta@xxxxxxxxxxxx>
---
arch/arc/kernel/unwind.c | 26 +++++++++++++++++++++++++-
1 file changed, 25 insertions(+), 1 deletion(-)

diff --git a/arch/arc/kernel/unwind.c b/arch/arc/kernel/unwind.c
index d5ffb4a78104..91f310465970 100644
--- a/arch/arc/kernel/unwind.c
+++ b/arch/arc/kernel/unwind.c
@@ -889,6 +889,19 @@ static int cie_validate(const u32 *cie, struct cie *t_cie)
return end - (const u8 *)cie;
}

+#define UNWIND_INSTRUMENT
+
+#ifdef UNWIND_INSTRUMENT
+u32 unw_t_min = 0xffffff, unw_t_max, unw_t_n;
+u64 unw_t_avg;
+
+static unsigned int get_c(void)
+{
+ write_aux_reg(0x600, 0x42); // ARC_REG_MCIP_CMD
+ return read_aux_reg(0x602); // ARC_REG_MCIP_READBACK
+}
+#endif
+
/* Unwind to previous to frame. Returns 0 if successful, negative
* number in case of an error. */
int arc_unwind(struct unwind_frame_info *frame)
@@ -907,7 +920,9 @@ int arc_unwind(struct unwind_frame_info *frame)
unsigned long addr;
struct eh_frame_header *hdr;
int ret = -EINVAL;
-
+#ifdef UNWIND_INSTRUMENT
+ unsigned int t0 = get_c(), t1, delta;
+#endif
unw_debug("\nUNWIND FRAME: -------------------------------------\n");
unw_debug("PC\t\t: 0x%lx %pS\nr31 [BLINK]\t: 0x%lx %pS\nr28 [SP]\t: 0x%lx\nr27 [FP]\t: 0x%lx\n",
UNW_PC(frame), (void *)UNW_PC(frame),
@@ -1072,6 +1087,15 @@ int arc_unwind(struct unwind_frame_info *frame)
ret = 0;
bad_unw:

+#ifdef UNWIND_INSTRUMENT
+ t1 = get_c();
+ delta = t1 - t0;
+ unw_t_min = min(unw_t_min, delta);
+ unw_t_max = max(unw_t_max, delta);
+ unw_t_n++;
+ unw_t_avg += delta;
+ printk("unw %d %s %lx\n", delta, !ret ? "O K":"nok", pc);
+#endif
return ret;
#undef FRAME_REG
}
--
1.9.1

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