On Mon, Dec 14, 2015 at 09:14:41AM +0800, Huawei Xie wrote:
> v2 changes:
> unroll the loop a bit to help the performance
>
> rte_pktmbuf_alloc_bulk allocates a bulk of packet mbufs.
>
> There is related thread about this bulk API.
> http://dpdk.org/dev/patchwork/patch/4718/
> Thanks to Konstantin's loop unrolling.
>
> Signed-off-by: Gerald Rogers <gerald.rogers at intel.com>
> Signed-off-by: Huawei Xie <huawei.xie at intel.com>
> Acked-by: Konstantin Ananyev <konstantin.ananyev at intel.com>
> ---
> lib/librte_mbuf/rte_mbuf.h | 50
> ++++++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 50 insertions(+)
>
> diff --git a/lib/librte_mbuf/rte_mbuf.h b/lib/librte_mbuf/rte_mbuf.h
> index f234ac9..4e209e0 100644
> --- a/lib/librte_mbuf/rte_mbuf.h
> +++ b/lib/librte_mbuf/rte_mbuf.h
> @@ -1336,6 +1336,56 @@ static inline struct rte_mbuf
> *rte_pktmbuf_alloc(struct rte_mempool *mp)
> }
>
> /**
> + * Allocate a bulk of mbufs, initialize refcnt and reset the fields to
> default
> + * values.
> + *
> + * @param pool
> + * The mempool from which mbufs are allocated.
> + * @param mbufs
> + * Array of pointers to mbufs
> + * @param count
> + * Array size
> + * @return
> + * - 0: Success
> + */
> +static inline int rte_pktmbuf_alloc_bulk(struct rte_mempool *pool,
> + struct rte_mbuf **mbufs, unsigned count)
It violates the coding style a bit.
> +{
> + unsigned idx = 0;
> + int rc;
> +
> + rc = rte_mempool_get_bulk(pool, (void **)mbufs, count);
> + if (unlikely(rc))
> + return rc;
> +
> + switch (count % 4) {
> + while (idx != count) {
Well, that's an awkward trick, putting while between switch and case.
How about moving the whole switch block ahead, and use goto?
switch (count % 4) {
case 3:
goto __3;
break;
case 2:
goto __2;
break;
...
}
It basically generates same instructions, yet it improves the
readability a bit.
--yliu
> + case 0:
> + RTE_MBUF_ASSERT(rte_mbuf_refcnt_read(mbufs[idx]) == 0);
> + rte_mbuf_refcnt_set(mbufs[idx], 1);
> + rte_pktmbuf_reset(mbufs[idx]);
> + idx++;
> + case 3:
> + RTE_MBUF_ASSERT(rte_mbuf_refcnt_read(mbufs[idx]) == 0);
> + rte_mbuf_refcnt_set(mbufs[idx], 1);
> + rte_pktmbuf_reset(mbufs[idx]);
> + idx++;
> + case 2:
> + RTE_MBUF_ASSERT(rte_mbuf_refcnt_read(mbufs[idx]) == 0);
> + rte_mbuf_refcnt_set(mbufs[idx], 1);
> + rte_pktmbuf_reset(mbufs[idx]);
> + idx++;
> + case 1:
> + RTE_MBUF_ASSERT(rte_mbuf_refcnt_read(mbufs[idx]) == 0);
> + rte_mbuf_refcnt_set(mbufs[idx], 1);
> + rte_pktmbuf_reset(mbufs[idx]);
> + idx++;
> + }
> + }
> + return 0;
> +}
> +
> +/**
> * Attach packet mbuf to another packet mbuf.
> *
> * After attachment we refer the mbuf we attached as 'indirect',
> --
> 1.8.1.4
