On Wed, Oct 02, 2024 at 08:41:33PM +0100, Vadim Fedorenko wrote:
> On 02/10/2024 16:54, Maciej Fijalkowski wrote:
> > This so we avoid dereferencing struct net_device within hot path.
> >
> > Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@xxxxxxxxx>
> > ---
> > include/net/xsk_buff_pool.h | 1 +
> > net/xdp/xsk_buff_pool.c | 1 +
> > net/xdp/xsk_queue.h | 2 +-
> > 3 files changed, 3 insertions(+), 1 deletion(-)
> >
> > diff --git a/include/net/xsk_buff_pool.h b/include/net/xsk_buff_pool.h
> > index 468a23b1b4c5..8223581d95f8 100644
> > --- a/include/net/xsk_buff_pool.h
> > +++ b/include/net/xsk_buff_pool.h
> > @@ -77,6 +77,7 @@ struct xsk_buff_pool {
> > u32 chunk_shift;
> > u32 frame_len;
> > u8 tx_metadata_len; /* inherited from umem */
> > + u32 xdp_zc_max_segs;
>
> It's better not to make holes in the struct. And looks like it's better
> to move it closer to free_list_cnt to put it on the same cache line with
> tx_descs which is accessed earlier in xskq_cons_read_desc_batch()
> (though the last point is not strict because both cache lines should be
> hot at the moment)
Hi Vadim,
Yeah I agree placement is awkward, i'll move this above tx_metadata_len to
keep booleans together. CL is correct though as ::unaligned is accessed
when parsing/validating descs so as you said, both these CLs are supposed
to be hot.
Thanks for review! Will send a v2.
>
> > u8 cached_need_wakeup;
> > bool uses_need_wakeup;
> > bool unaligned;
>
>
