> -----Original Message----- > From: dev [mailto:dev-bounces at dpdk.org] On Behalf Of Zoltan Kiss > Sent: Monday, May 18, 2015 1:28 PM > To: dev at dpdk.org > Subject: Re: [dpdk-dev] [PATCH] mempool: limit cache_size > > Hi, > > Any opinion on this patch? > > Regards, > > Zoltan > > On 13/05/15 19:59, Zoltan Kiss wrote: > > Otherwise cache_flushthresh can be bigger than n, and > > a consumer can starve others by keeping every element > > either in use or in the cache. > > > > Signed-off-by: Zoltan Kiss <zoltan.kiss at linaro.org> > > --- > > lib/librte_mempool/rte_mempool.c | 3 ++- > > lib/librte_mempool/rte_mempool.h | 2 +- > > 2 files changed, 3 insertions(+), 2 deletions(-) > > > > diff --git a/lib/librte_mempool/rte_mempool.c > > b/lib/librte_mempool/rte_mempool.c > > index cf7ed76..ca6cd9c 100644 > > --- a/lib/librte_mempool/rte_mempool.c > > +++ b/lib/librte_mempool/rte_mempool.c > > @@ -440,7 +440,8 @@ rte_mempool_xmem_create(const char *name, unsigned n, > > unsigned elt_size, > > mempool_list = RTE_TAILQ_CAST(rte_mempool_tailq.head, rte_mempool_list); > > > > /* asked cache too big */ > > - if (cache_size > RTE_MEMPOOL_CACHE_MAX_SIZE) { > > + if (cache_size > RTE_MEMPOOL_CACHE_MAX_SIZE || > > + (uint32_t) cache_size * CACHE_FLUSHTHRESH_MULTIPLIER > n) { > > rte_errno = EINVAL; > > return NULL; > > }
Why just no 'cache_size > n' then? Konstantin > > diff --git a/lib/librte_mempool/rte_mempool.h > > b/lib/librte_mempool/rte_mempool.h > > index 9001312..a4a9610 100644 > > --- a/lib/librte_mempool/rte_mempool.h > > +++ b/lib/librte_mempool/rte_mempool.h > > @@ -468,7 +468,7 @@ typedef void (rte_mempool_ctor_t)(struct rte_mempool *, > > void *); > > * If cache_size is non-zero, the rte_mempool library will try to > > * limit the accesses to the common lockless pool, by maintaining a > > * per-lcore object cache. This argument must be lower or equal to > > - * CONFIG_RTE_MEMPOOL_CACHE_MAX_SIZE. It is advised to choose > > + * CONFIG_RTE_MEMPOOL_CACHE_MAX_SIZE and n / 1.5. It is advised to choose > > * cache_size to have "n modulo cache_size == 0": if this is > > * not the case, some elements will always stay in the pool and will > > * never be used. The access to the per-lcore table is of course > >
