Re: [PATCH] perf diff: Report noisy for cycles diff

2019-07-17 Thread Jin, Yao 




On 7/16/2019 4:51 PM, Jiri Olsa wrote:

On Fri, Jul 12, 2019 at 03:53:55PM +0800, Jin Yao wrote:

This patch prints the stddev and hist for the cycles diff of
program block. It can help us to understand if the cycles diff
is noisy or not.


I'm getting compile error:

   CC   builtin-diff.o
builtin-diff.c: In function ‘compute_cycles_diff’:
builtin-diff.c:712:10: error: taking the absolute value of unsigned type ‘u64’ 
{aka ‘long unsigned int’} has no effect [-Werror=absolute-value]
   712 |  labs(pair->block_info->cycles_spark[i] -
   |  ^~~~
cc1: all warnings being treated as errors
mv: cannot stat './.builtin-diff.o.tmp': No such file or directory




Oh, sorry about that. My gcc (gcc version 7.4.0 (Ubuntu 
7.4.0-1ubuntu1~18.04.1)) didn't report this error. :(


u64 - u64 is u64. I should define it as s64.

Thanks for reminding me.

Thanks
Jin Yao


jirka

Re: [PATCH] perf diff: Report noisy for cycles diff

2019-07-16 Thread Jiri Olsa 
On Fri, Jul 12, 2019 at 03:53:55PM +0800, Jin Yao wrote:
> This patch prints the stddev and hist for the cycles diff of
> program block. It can help us to understand if the cycles diff
> is noisy or not.

I'm getting compile error:

  CC   builtin-diff.o
builtin-diff.c: In function ‘compute_cycles_diff’:
builtin-diff.c:712:10: error: taking the absolute value of unsigned type ‘u64’ 
{aka ‘long unsigned int’} has no effect [-Werror=absolute-value]
  712 |  labs(pair->block_info->cycles_spark[i] -
  |  ^~~~
cc1: all warnings being treated as errors
mv: cannot stat './.builtin-diff.o.tmp': No such file or directory


jirka