[aarch64-port-dev ] Java callstacks are truncated in perf on aarch64

[Andrew Haley]

On 05/06/2015 12:45 PM, Alexeev, Alexander wrote:

> As far as I understand this is controversial topic if perf should
> recognize java frames or JVM has a mode where stacks can be
> traced. One way or another it is critical for performance tuning to
> be able to collect performance profiles with call trees, otherwise
> analysis is too complex.

It would be nice to have.  Ed Nevill has a patch to support real frame
pointers, but I don't know if perf will work with that.  That's more
of a question for perf.

> It is important especially now when aarch64 doesn't have solid
> performance.
> 
> Even if it was coincidence why not to keep it

I have no idea what "it" is.

> or provide an option for profiling?

It would be nice.  It'll probably require someone to work with the
perf developers.

> As far as I can see X86 version works with perf.

OK.  So someone needs to investigate why it works, and if there is
anything we can import from there.

Andrew.