Re: [PATCH net-next v2] net: page_pool: optimize page pool page allocation in NUMA scenario

[wangjie (L)]

On 2022/7/1 15:56, Jesper Dangaard Brouer wrote:
> On 01/07/2022 06.15, Jakub Kicinski wrote:
> > On Wed, 29 Jun 2022 21:33:05 +0800 Guangbin Huang wrote:
> > > +#ifdef CONFIG_NUMA
> > > +    pref_nid = (pool->p.nid == NUMA_NO_NODE) ? numa_mem_id() :
> > > pool->p.nid;
> > > +#else
> > > +    /* Ignore pool->p.nid setting if !CONFIG_NUMA */
> > > +    pref_nid = NUMA_NO_NODE;
> > > +#endif
> >
> > Please factor this out to a helper, this is a copy of the code from
> > page_pool_refill_alloc_cache() and #ifdefs are a little yuck.
>
> I would say simply use 'pool->p.nid' in the call to
> alloc_pages_bulk_array_node() and drop this optimization (that was
> copy-pasted from fast-path).
>
> The optimization avoids one reading from memory compile time depending
> on CONFIG_NUMA.  It is *not* worth doing in this code path which is even
> named "slow" (__page_pool_alloc_pages_slow).
>
> --Jesper
Simply use pool->p.nid looks simply and makes sense in both scenario. I 
will rewrite and test the patch in next version.
> .