Re: [PATCH] perf report: Do not process non-JIT BPF ksymbol events

[Namhyung Kim]

On Wed, 05 Mar 2025 15:28:38 -0800, Namhyung Kim wrote:
> The length of PERF_RECORD_KSYMBOL for BPF is a size of JITed code so
> it'd be 0 when it's not JITed.  The ksymbol is needed to symbolize the
> code when it gets samples in the region but non-JITed code cannot get
> samples.  Thus it'd be ok to ignore them.
> 
> Actually it caused a performance issue in the perf tools on old ARM
> kernels where it can refuse to JIT some BPF codes.  It ended up
> splitting the existing kernel map (kallsyms).  And later lookup for a
> kernel symbol would create a new kernel map from kallsyms and then
> split it again and again. :(
> 
> [...]
Applied to perf-tools-next, thanks!

Best regards,
Namhyung