Hey,
I'm observing misaligned output of perf stat --topdown:
$ sudo perf stat --topdown --cpu 1 -a find /state > /dev/null
Performance counter stats for 'system wide':
retiring bad speculation
frontend bound backend bound
S0-D0-C1 1 30.4% 13.4%
38.0% 18.2%
$ sudo perf stat --topdown --cpu 1 -a find /state > /dev/null
Performance counter stats for 'system wide':
retiring bad speculation
frontend bound backend bound
S0-D0-C1 1 27.5% 6.5%
24.1% 41.9%
$ sudo perf stat --topdown --cpu 1 -a find /state > /dev/null
Performance counter stats for 'system wide':
retiring bad speculation
frontend bound backend bound
S0-D0-C1 1 29.6% 12.3%
23.7% 34.4%
It may be hard to notice in narrow plaintext email, so here's a gist:
* https://gist.github.com/bobrik/ea5ddd8eb1629c350c898093f39ac7ee
I think there are two issues:
* Sometimes output is misaligned, which may or may not depend on the
length of the printed value (<10.0% is misaligned, >=10.0% is ok)
* Values are never really aligned to headers (except for maybe the first column)
This is on 5.4.0.