* kan.li...@linux.intel.com <kan.li...@linux.intel.com> wrote:
> Performance impact:
> The processing time may increase with the LBR stitching approach
> enabled. The impact depends on the number of samples with stitched LBRs.
>
> For sqlite's tcltest,
> perf record --call-graph lbr -- make tcltest
> perf report --stitch-lbr
>
> There are 4.11% samples has stitched LBRs.
> Total number of samples: 2833728
> The number of samples with stitched LBRs 116478
>
> The processing time of perf report increases 6.8%
> Without --stitch-lbr: 55906106 usec
> With --stitch-lbr: 59728701 usec
>
> For a simple test case tchain_edit with 43 depth of call stacks.
> perf record --call-graph lbr -- ./tchain_edit
> perf report --stitch-lbr
>
> There are 99.9% samples has stitched LBRs.
> Total number of samples: 10915
> The number of samples with stitched LBRs 10905
>
> The processing time of perf report increases 67.4%
> Without --stitch-lbr: 11970508 usec
> With --stitch-lbr: 20036055 usec
That cost seems pretty high, while the feature sounds useful - is there
any way to speed this up?
Thanks,
Ingo
