2 ms·
The problem with Intel LBR (last branch records) is that the depth of the call stack is relatively limited. It depends on the generation of CPU, but LWN has a
by rwmj 2y ago
The problem with Intel LBR (last branch records) is that the depth of the call stack is relatively limited. It depends on the generation of CPU, but LWN has a table here: https://lwn.net/Articles/680985/ https://lwn.net/Articles/680985/ Anything less than 32 is fairly useless for profiling from the kernel through to userspace.
- fooblaster 2y agoYeah, right. I still seem to get far more "comprehensible" traces when using it, even with this limitation. It's often really easy to localize where a trace is coming from, even when truncated. It probably breaks flamegraphs though.