Re: [Patch v2] net/mana: use rte_pktmbuf_alloc_bulk for allocating RX WQEs

[Stephen Hemminger <stephen@networkplumber.org>]

On Tue, 30 Jan 2024 10:19:32 +0000
Ferruh Yigit <ferruh.yigit@amd.com> wrote:

> > -mana_alloc_and_post_rx_wqes(struct mana_rxq *rxq)
> > +mana_alloc_and_post_rx_wqes(struct mana_rxq *rxq, uint32_t count)
> >  {
> >  	int ret;
> >  	uint32_t i;
> > +	struct rte_mbuf **mbufs;
> > +
> > +	mbufs = rte_calloc_socket("mana_rx_mbufs", count, sizeof(struct rte_mbuf *),
> > +				  0, rxq->mp->socket_id);
> > +	if (!mbufs)
> > +		return -ENOMEM;
> >  
> 
> 'mbufs' is temporarily storage for allocated mbuf pointers, why not
> allocate if from stack instead, can be faster and easier to manage:
> "struct rte_mbuf *mbufs[count]"

That would introduce a variable length array.
VLA's should be removed, they are not supported on Windows and many
security tools flag them. The problem is that it makes the code brittle
if count gets huge.

But certainly regular calloc() or alloca() would work here.