> -----Original Message-----
> From: Olivier MATZ [mailto:olivier.matz at 6wind.com]
> Sent: Monday, February 09, 2015 4:01 AM
> To: Liang, Cunming; dev at dpdk.org
> Subject: Re: [dpdk-dev] [PATCH v4 14/17] mempool: add support to non-EAL
> thread
>
> Hi,
>
> On 02/02/2015 03:02 AM, Cunming Liang wrote:
> > For non-EAL thread, bypass per lcore cache, directly use ring pool.
> > It allows using rte_mempool in either EAL thread or any user pthread.
> > As in non-EAL thread, it directly rely on rte_ring and it's none preemptive.
> > It doesn't suggest to run multi-pthread/cpu which compete the rte_mempool.
> > It will get bad performance and has critical risk if scheduling policy is
> > RT.
> >
> > Signed-off-by: Cunming Liang <cunming.liang at intel.com>
> > ---
> > lib/librte_mempool/rte_mempool.h | 18 +++++++++++-------
> > 1 file changed, 11 insertions(+), 7 deletions(-)
> >
> > diff --git a/lib/librte_mempool/rte_mempool.h
> b/lib/librte_mempool/rte_mempool.h
> > index 3314651..4845f27 100644
> > --- a/lib/librte_mempool/rte_mempool.h
> > +++ b/lib/librte_mempool/rte_mempool.h
> > @@ -198,10 +198,12 @@ struct rte_mempool {
> > * Number to add to the object-oriented statistics.
> > */
> > #ifdef RTE_LIBRTE_MEMPOOL_DEBUG
> > -#define __MEMPOOL_STAT_ADD(mp, name, n) do { \
> > - unsigned __lcore_id = rte_lcore_id(); \
> > - mp->stats[__lcore_id].name##_objs += n; \
> > - mp->stats[__lcore_id].name##_bulk += 1; \
> > +#define __MEMPOOL_STAT_ADD(mp, name, n) do { \
> > + unsigned __lcore_id = rte_lcore_id(); \
> > + if (__lcore_id < RTE_MAX_LCORE) { \
> > + mp->stats[__lcore_id].name##_objs += n; \
> > + mp->stats[__lcore_id].name##_bulk += 1; \
> > + } \
>
> Does it mean that we have no statistics for non-EAL threads?
> (same question for rings and timers in the next patches)
[LCM] Yes, it is in this patch set, mainly focus on EAL thread and make sure no
running issue on non-EAL thread.
For full non-EAL function, will have other patch set to enhance non-EAL thread
as the 2nd step.
>
>
> > } while(0)
> > #else
> > #define __MEMPOOL_STAT_ADD(mp, name, n) do {} while(0)
> > @@ -767,8 +769,9 @@ __mempool_put_bulk(struct rte_mempool *mp, void
> * const *obj_table,
> > __MEMPOOL_STAT_ADD(mp, put, n);
> >
> > #if RTE_MEMPOOL_CACHE_MAX_SIZE > 0
> > - /* cache is not enabled or single producer */
> > - if (unlikely(cache_size == 0 || is_mp == 0))
> > + /* cache is not enabled or single producer or none EAL thread */
> > + if (unlikely(cache_size == 0 || is_mp == 0 ||
> > + lcore_id >= RTE_MAX_LCORE))
> > goto ring_enqueue;
> >
> > /* Go straight to ring if put would overflow mem allocated for cache */
> > @@ -952,7 +955,8 @@ __mempool_get_bulk(struct rte_mempool *mp, void
> **obj_table,
> > uint32_t cache_size = mp->cache_size;
> >
> > /* cache is not enabled or single consumer */
> > - if (unlikely(cache_size == 0 || is_mc == 0 || n >= cache_size))
> > + if (unlikely(cache_size == 0 || is_mc == 0 ||
> > + n >= cache_size || lcore_id >= RTE_MAX_LCORE))
> > goto ring_dequeue;
> >
> > cache = &mp->local_cache[lcore_id];
> >
>
> What is the performance impact of adding this test?
[LCM] By perf in unit test, it's almost the same. But haven't measure EAL
thread and non-EAL thread share the same mempool.
>
>
> Regards,
> Olivier
