On Thu, Mar 09, 2023 at 01:26:18AM +0900, Leesoo Ahn wrote: > The current codebase calls the function no matter net device has XDP > programs or not. So the finalize function is being called everytime when RX > bottom-half in progress. It needs a few machine instructions for nothing > in the case that XDP programs are not attached at all. > > Lets it call the function on a condition that if xdp_status variable has > not zero value. That means XDP programs are attached to the net device > and it should be finalized based on the variable. > > The following instructions show that it's better than calling the function > unconditionally. > > 0.31 │6b8: ldr w0, [sp, #196] > │ ┌──cbz w0, 6cc > │ │ mov x1, x0 > │ │ mov x0, x27 > │ │→ bl stmmac_finalize_xdp_rx > │6cc:└─→ldr x1, [sp, #176] > > with 'if (xdp_status)' statement, jump to '6cc' label if xdp_status has > zero value. > > Signed-off-by: Leesoo Ahn <lsahn@xxxxxxxxxx> Hi Leesoo, I am curious to know if you considered going a step further and using a static key. Link: https://www.kernel.org/doc/html/latest/staging/static-keys.html
