Re: [PATCH bpf] bpf: powerpc64: optimize JIT passes for bpf function calls

Hi Sandipan,

On 12/03/2018 01:21 PM, Sandipan Das wrote:

Once the JITed images for each function in a multi-function program
are generated after the first three JIT passes, we only need to fix
the target address for the branch instruction corresponding to each
bpf-to-bpf function call.

This introduces the following optimizations for reducing the work
done by the JIT compiler when handling multi-function programs:

  [1] Instead of doing two extra passes to fix the bpf function calls,
      do just one as that would be sufficient.

  [2] During the extra pass, only overwrite the instruction sequences
      for the bpf-to-bpf function calls as everything else would still
      remain exactly the same. This also reduces the number of writes
      to the JITed image.

  [3] Do not regenerate the prologue and the epilogue during the extra
      pass as that would be redundant.

Signed-off-by: Sandipan Das <redacted>

Thanks for the patch, just to clarify, it's targeted at bpf-next and
not bpf, correct?

Thanks,
Daniel