[dpdk-dev] [PATCH] app/testpmd: reduce memory consumption

[Thomas Monjalon]

21/11/2019 16:12, David Marchand:
> Following [1], testpmd memory consumption has skyrocketted.
> The rte_port structure has gotten quite fat.
> 
> struct rte_port {
> [...]
>   struct rte_eth_rxconf rx_conf[65536];            /* 266280 3145728 */
>   /* --- cacheline 53312 boundary (3411968 bytes) was 40 bytes ago --- */
>   struct rte_eth_txconf tx_conf[65536];            /* 3412008 3670016 */
>   /* --- cacheline 110656 boundary (7081984 bytes) was 40 bytes ago --- */
> [...]
>   /* size: 8654936, cachelines: 135234, members: 31 */
> [...]
> 
> testpmd handles RTE_MAX_ETHPORTS ports (32 by default) which means that it
> needs ~256MB just for this internal representation.
> 
> The reason is that a testpmd rte_port (the name is quite confusing, as
> it is a local type) maintains configurations for all queues of a port.
> But where you would expect testpmd to use RTE_MAX_QUEUES_PER_PORT as the
> maximum queue count, the rte_port uses MAX_QUEUE_ID set to 64k.
> 
> Prefer the ethdev maximum value.
> 
> After this patch:
> struct rte_port {
> [...]
>   struct rte_eth_rxconf      rx_conf[1025];        /*  8240 49200 */
>   /* --- cacheline 897 boundary (57408 bytes) was 32 bytes ago --- */
>   struct rte_eth_txconf      tx_conf[1025];        /* 57440 57400 */
>   /* --- cacheline 1794 boundary (114816 bytes) was 24 bytes ago --- */
> [...]
>   /* size: 139488, cachelines: 2180, members: 31 */
> [...]
> 
> [1]: https://git.dpdk.org/dpdk/commit/?id=436b3a6b6e62
> 
> Signed-off-by: David Marchand <david.marchand at redhat.com>

Acked-by: Thomas Monjalon <thomas at monjalon.net>

I was really concerned by the memory requirement increase
due to my patch on ethdev structs.
Thank you for finding these giant arrays.