-----Original Message-----
> Date: Fri, 9 Mar 2018 16:42:03 +0000
> From: Konstantin Ananyev <konstantin.anan...@intel.com>
> To: dev@dpdk.org
> CC: Konstantin Ananyev <konstantin.anan...@intel.com>
> Subject: [dpdk-dev] [PATCH v1 3/5] bpf: introduce basic RX/TX BPF filters
> X-Mailer: git-send-email 1.7.0.7
>
> Introduce API to install BPF based filters on ethdev RX/TX path.
> Current implementation is pure SW one, based on ethdev RX/TX
> callback mechanism.
>
> Signed-off-by: Konstantin Ananyev <konstantin.anan...@intel.com>
> ---
> lib/librte_bpf/Makefile | 2 +
> lib/librte_bpf/bpf_pkt.c | 524
> +++++++++++++++++++++++++++++++++++++
> lib/librte_bpf/rte_bpf_ethdev.h | 50 ++++
> lib/librte_bpf/rte_bpf_version.map | 4 +
> 4 files changed, 580 insertions(+)
> create mode 100644 lib/librte_bpf/bpf_pkt.c
> create mode 100644 lib/librte_bpf/rte_bpf_ethdev.h
>
> diff --git a/lib/librte_bpf/Makefile b/lib/librte_bpf/Makefile
> +
> +/*
> + * information about all installed BPF rx/tx callbacks
> + */
> +
> +struct bpf_eth_cbi {
> + uint32_t use; /*usage counter */
> + void *cb; /* callback handle */
> + struct rte_bpf *bpf;
> + struct rte_bpf_jit jit;
> +} __rte_cache_aligned;
> +
> +/*
> + * Odd number means that callback is used by datapath.
> + * Even number means that callback is not used by datapath.
> + */
> +#define BPF_ETH_CBI_INUSE 1
> +
> +static struct bpf_eth_cbi rx_cbi[RTE_MAX_ETHPORTS][RTE_MAX_QUEUES_PER_PORT];
> +static struct bpf_eth_cbi tx_cbi[RTE_MAX_ETHPORTS][RTE_MAX_QUEUES_PER_PORT];
How about allocating this memory from huge page?
> +
> +/*
> + * Marks given callback as used by datapath.
> + */
> +static __rte_always_inline void
> +bpf_eth_cbi_inuse(struct bpf_eth_cbi *cbi)
> +{
> + cbi->use++;
> + /* make sure no store/load reordering could happen */
> + rte_smp_mb();
This is an full barrier on non x86. How about a light version of this
logic? See below.
> +}
> +
> +/*
> + * Marks given callback list as not used by datapath.
> + */
> +static __rte_always_inline void
> +bpf_eth_cbi_unuse(struct bpf_eth_cbi *cbi)
> +{
> + /* make sure all previous loads are completed */
> + rte_smp_rmb();
> + cbi->use++;
> +}
> +
> +/*
> + * Waits till datapath finished using given callback.
> + */
> +static void
> +bpf_eth_cbi_wait(const struct bpf_eth_cbi *cbi)
> +{
> + uint32_t nuse, puse;
> +
> + /* make sure all previous loads and stores are completed */
> + rte_smp_mb();
> +
Read conjunction with below change
#if 0
> + puse = cbi->use;
> +
> + /* in use, busy wait till current RX/TX iteration is finished */
> + if ((puse & BPF_ETH_CBI_INUSE) != 0) {
> + do {
> + rte_pause();
> + rte_compiler_barrier();
> + nuse = cbi->use;
> + } while (nuse == puse);
> + }
#else
cbi->cb = NULL;
while (likely(cb->done != 1)) {
rte_pause();
rte_smb_rmb();
}
or any other logic using flag to wait until callback completes.
#endif
> +}
> +
> +
> +/*
> + * RX/TX callbacks for raw data bpf.
> + */
> +
> +static uint16_t
> +bpf_rx_callback_vm(__rte_unused uint16_t port, __rte_unused uint16_t queue,
> + struct rte_mbuf *pkt[], uint16_t nb_pkts,
> + __rte_unused uint16_t max_pkts, void *user_param)
> +{
> + struct bpf_eth_cbi *cbi;
> + uint16_t rc;
> +
> + cbi = user_param;
> +
Read conjunction with above change
#if 0
> + bpf_eth_cbi_inuse(cbi);
> + rc = (cbi->cb != NULL) ?
> + pkt_filter_vm(cbi->bpf, pkt, nb_pkts, 1) :
> + nb_pkts;
> + bpf_eth_cbi_unuse(cbi);
#else
if (likely(cbi->cb != NULL))
return pkt_filter_vm(cbi->bpf, pkt, nb_pkts, 1) :
else {
cbi->done = 1;
rte_smb_wmb();
return nb_pkts;
}
#endif
> + return rc;
> +}
> +
