Re: [PATCH v4 1/3] powerpc/perf: Use stack siar instead of mfspr

2021-08-27 Thread Michael Ellerman 
On Wed, 18 Aug 2021 22:45:54 +0530, Kajol Jain wrote:
> Minor optimization in the 'perf_instruction_pointer' function code by
> making use of stack siar instead of mfspr.
> 
> 
> 
> 

Applied to powerpc/next.

[1/3] powerpc/perf: Use stack siar instead of mfspr
  https://git.kernel.org/powerpc/c/b1643084d164cea0c107a39bcdf0119fc52619af
[2/3] powerpc/perf: Drop the case of returning 0 as instruction pointer
  https://git.kernel.org/powerpc/c/cc90c6742ef5b438f4cb86029d7a794bd0a44a06
[3/3] powerpc/perf: Fix the check for SIAR value
  https://git.kernel.org/powerpc/c/3c69a5f3fa3e312689ec218b5059784d49d7

cheers

Re: [PATCH v4 1/3] powerpc/perf: Use stack siar instead of mfspr

2021-08-18 Thread Nageswara Sastry 




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 



Tested this patch series, not seeing any '0' values.
Tested-by: Nageswara R Sastry 

example output:
# perf report -D | grep addr
0 26236879714 0x3dcc8 [0x38]: PERF_RECORD_SAMPLE(IP, 0x1): 1446/1446: 
0xc0113584 period: 1 addr: 0
0 26236882500 0x3dd00 [0x38]: PERF_RECORD_SAMPLE(IP, 0x1): 1446/1446: 
0xc0113584 period: 1 addr: 0
0 26236883436 0x3dd38 [0x38]: PERF_RECORD_SAMPLE(IP, 0x1): 1446/1446: 
0xc0113584 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

[PATCH v4 1/3] powerpc/perf: Use stack siar instead of mfspr

2021-08-18 Thread Kajol Jain 
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 
---
 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
-- 
2.26.2