On 18/08/21 10:45 pm, Kajol Jain wrote:
Minor optimization in the 'perf_instruction_pointer' function code by
making use of stack siar instead of mfspr.
Fixes: 75382aa72f06 ("powerpc/perf: Move code to select SIAR or pt_regs
into perf_read_regs")
Signed-off-by: Kajol Jain <kj...@linux.ibm.com>
Tested this patch series, not seeing any '0' values.
Tested-by: Nageswara R Sastry <rnsas...@linux.ibm.com>
example output:
# perf report -D | grep addr
0 26236879714 0x3dcc8 [0x38]: PERF_RECORD_SAMPLE(IP, 0x1): 1446/1446:
0xc000000000113584 period: 1 addr: 0
0 26236882500 0x3dd00 [0x38]: PERF_RECORD_SAMPLE(IP, 0x1): 1446/1446:
0xc000000000113584 period: 1 addr: 0
0 26236883436 0x3dd38 [0x38]: PERF_RECORD_SAMPLE(IP, 0x1): 1446/1446:
0xc000000000113584 period: 10 addr: 0
...
---
arch/powerpc/perf/core-book3s.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/powerpc/perf/core-book3s.c b/arch/powerpc/perf/core-book3s.c
index bb0ee716de91..1b464aad29c4 100644
--- a/arch/powerpc/perf/core-book3s.c
+++ b/arch/powerpc/perf/core-book3s.c
@@ -2260,7 +2260,7 @@ unsigned long perf_instruction_pointer(struct pt_regs
*regs)
else
return regs->nip;
} else if (use_siar && siar_valid(regs))
- return mfspr(SPRN_SIAR) + perf_ip_adjust(regs);
+ return siar + perf_ip_adjust(regs);
else if (use_siar)
return 0; // no valid instruction pointer
else
--
Thanks and Regards
R.Nageswara Sastry
