Re: [PATCH] perf/amd/ibs: add phy_addr_only software filter for ibs_op

[Ravi Bangoria]

Huang,

>> Why not simply use the BPF filter?
>>   $ perf record -e ibs_op// --phys-data --filter 'phys_addr != 0' ...
> 
> I did try the BPF filter.
> 
> Measurements below are system-wide ibs_op sampling for 5s on a
> 384-CPU Hygon box under a 400-thread sysbench oltp_read_only load
> at three sampling periods:
> 
>     -c     filter        valid samples    
>   ------  ------------  ---------- 
>   100000  phy_addr_only  19,345,907 
>   100000  BPF filter     17,939,819 
> 
>    30000  phy_addr_only  54,670,617 
>    30000  BPF filter     47,926,784 
> 
>    10000  phy_addr_only  61,606,488 
>    10000  BPF filter     40,826,086 
> 
> 
> The phy_addr_only produces more *valid* samples than the BPF filter.

Can you please confirm if those additional samples are genuinely valid.

Thanks,
Ravi