Hi all,
The rte_pktmbuf_free() function could be optimized by freeing multiple segments
in bulk using rte_mempool_put_bulk().
I got this idea while optimizing the rte_pktmbuf_free_bulk() function
similarly, as suggested by Stephen Hemminger and Konstantin Ananyev.
If any of you DPDK performance freaks want to test this concept, here's some
source code to get you started.
/**
* @internal Size of the array holding mbufs from the same membool to be freed
* in bulk.
*/
#define RTE_PKTMBUF_FREE_BULK_SZ 64
/**
* @internal helper function for freeing a bulk of mbufs via an array holding
* mbufs from the same mempool.
*/
static __rte_always_inline void
rte_pktmbuf_free_seg_via_array(struct rte_mbuf *m,
struct rte_mbuf * * const free, unsigned int * const nb_free)
{
m = rte_pktmbuf_prefree_seg(m);
if (likely(m != NULL)) {
if (*nb_free >= RTE_PKTMBUF_FREE_BULK_SZ ||
(*nb_free > 0 && m->pool != free[0]->pool)) {
rte_mempool_put_bulk(free[0]->pool, (void **)free,
*nb_free);
*nb_free = 0;
}
free[(*nb_free)++] = m;
}
}
/**
* Free a packet mbuf back into its original mempool.
*
* Free an mbuf, and all its segments in case of chained buffers. Each
* segment is added back into its original mempool.
*
* @param m
* The packet mbuf to be freed. If NULL, the function does nothing.
*/
static inline void rte_pktmbuf_free(struct rte_mbuf *m)
{
struct rte_mbuf *m_next, *free[RTE_PKTMBUF_FREE_BULK_SZ];
unsigned int nb_free = 0;
if (unlikely(m == NULL)) return;
__rte_mbuf_sanity_check(m, 1);
do {
m_next = m->next;
rte_pktmbuf_free_seg_via_array(m, free, &nb_free);
m = m_next;
} while (m != NULL);
if (nb_free > 0)
rte_mempool_put_bulk(free[0]->pool, (void **)free, nb_free);
}
Med venlig hilsen / kind regards
Morten Brørup
CTO
SmartShare Systems A/S
Tonsbakken 16-18
DK-2740 Skovlunde
Denmark
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m...@smartsharesystems.com
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