[PATCH v3 10/27] net/i40e: avoid rte malloc in RSS RETA operations

[Stephen Hemminger]

On Tue, 17 Feb 2026 12:46:44 +0000
Bruce Richardson <bruce.richardson at intel.com> wrote:

> On Tue, Feb 17, 2026 at 01:32:05PM +0100, Burakov, Anatoly wrote:
> > On 2/16/2026 6:06 PM, Bruce Richardson wrote:  
> > > On Wed, Feb 11, 2026 at 01:52:52PM +0000, Anatoly Burakov wrote:  
> > > > Currently, when updating or querying RSS redirection table (RETA), we
> > > > are using rte_zmalloc followed by an immediate rte_free. This is not
> > > > needed as this memory is not being stored anywhere, so replace it with
> > > > regular malloc/free.
> > > > 
> > > > Signed-off-by: Anatoly Burakov <anatoly.burakov at intel.com>
> > > > ---
> > > >   drivers/net/intel/i40e/i40e_ethdev.c | 8 ++++----
> > > >   1 file changed, 4 insertions(+), 4 deletions(-)
> > > > 
> > > > diff --git a/drivers/net/intel/i40e/i40e_ethdev.c b/drivers/net/intel/i40e/i40e_ethdev.c
> > > > index 06430e6319..654b0e5d16 100644
> > > > --- a/drivers/net/intel/i40e/i40e_ethdev.c
> > > > +++ b/drivers/net/intel/i40e/i40e_ethdev.c
> > > > @@ -4630,7 +4630,7 @@ i40e_dev_rss_reta_update(struct rte_eth_dev *dev,
> > > >   		return -EINVAL;
> > > >   	}
> > > > -	lut = rte_zmalloc("i40e_rss_lut", reta_size, 0);
> > > > +	lut = calloc(1, reta_size);
> > > >   	if (!lut) {
> > > >   		PMD_DRV_LOG(ERR, "No memory can be allocated");
> > > >   		return -ENOMEM;
> > > > @@ -4649,7 +4649,7 @@ i40e_dev_rss_reta_update(struct rte_eth_dev *dev,
> > > >   	pf->adapter->rss_reta_updated = 1;
> > > >   out:
> > > > -	rte_free(lut);
> > > > +	free(lut);
> > > >   	return ret;
> > > >   }  
> > > 
> > > For i40e do we not have a reasonable max reta size that we could use for a
> > > local array variable, save allocating and freeing entirely?
> > >   
> > 
> > It's on the order of kilobytes I think so I decided against stack allocation
> > for this scenario.
> >   
> If it's only a kilobyte, I would tend to go with stack allocation.
> However, it's up to you.

Agree, anything under 4K seems reasonable to be on stack.