Re: Wrong Perf Backtraces

Hi,
I think that I should give up and assume that all illogical repeated 
addresses are inlines. Thanks everybody, especially, Jirka, Milian, 
Arnaldo and Steven. Perhaps some day I will be back and try to dig 
deeper (with your hints and assistance).
Regards.

On 2020-04-01 01:27, ahmadkhorrami wrote:

> Hi,
> On 2020-03-31 19:59, Milian Wolff wrote:
> 
> On Dienstag, 31. März 2020 17:02:37 CEST ahmadkhorrami wrote:
> 
> Hi Milian,
> Thanks for the detailed answer. Well, the bug you mentioned is bad 
> news.
> Because I sample using uppp. Perhaps this leads to these weird traces.
> Please read the full thread from here on:
> 
> https://lkml.org/lkml/2018/11/2/86
> 
> But as I said - it should be easy to check if this is really the issue 
> are
> running into or not: Try to see if you see the problem when you sample 
> without
> `ppp`. If not, then you can be pretty sure it's this issue. If you 
> still see
> it, then it's something different.
  Well, the problem exists even when ":uppp" is changed to ":u".

>> Is this a purely software bug?
> 
> I wouldn't call it that, personally. Rather, it's a limitation in the 
> hardware
> and software. We would need something completely different to "fix" 
> this, i.e.
> something like a deeper LBR. That's btw another alternative you could 
> try:
> `perf record --call-graph lbr` and live with the short call stacks. But 
> at
> least these should be correct (afaik). For me personally they are 
> always far
> too short and thus not practical to use in reality.
> 
> Cheers
  Regards.