[ovs-dev] netdev-dpdk: Memset rte_flow_item on a need basis.

Ilya Maximets i.maximets at samsung.com
Mon Feb 4 15:40:34 UTC 2019


On 04.02.2019 18:08, Asaf Penso wrote:
> 
> 
> Regards,
> Asaf Penso
> 
>> -----Original Message-----
>> From: Ilya Maximets <i.maximets at samsung.com>
>> Sent: Monday, February 4, 2019 4:14 PM
>> To: Asaf Penso <asafp at mellanox.com>; ovs-dev at openvswitch.org
>> Cc: Roni Bar Yanai <roniba at mellanox.com>; Stokes, Ian
>> <ian.stokes at intel.com>
>> Subject: Re: [ovs-dev] netdev-dpdk: Memset rte_flow_item on a need basis.
>>
>> On 04.02.2019 15:50, Asaf Penso wrote:
>>> In netdev_dpdk_add_rte_flow_offload function different rte_flow_item
>>> are created as part of the pattern matching.
>>>
>>> For most of them, there is a check whether the wildcards are not zero.
>>> In case of zero, nothing is being done with the rte_flow_item.
>>>
>>> Befor the wildcard check, and regardless of the result, the
>>> rte_flow_item is being memset.
>>>
>>> The patch moves the memset function only if the condition of the
>>> wildcard is true, thus saving cycles of memset if not needed.
>>
>> Structures are actually used only inside their 'if' blocks.
>> IMHO, it's better to move the definitions inside too.
>>
> 
> Inside each 'if' block there is a call to add_flow_pattern that updates the pattern's pointers to these structs.
> Having them defined inside the block will cause their value to be corrupted once we exit the block.
> They are needed all the way until rte_flow_create call.

Oh. Sorry. You're right. I forget about that.

BTW, as you touching this code, maybe you could make it a bit more
coding-style compliant ? It's about sizeof operator. Coding-style
asks to not parenthesize the operand. Like this:

    memset(&eth_spec, 0, sizeof eth_spec);

It'll be nice if you could fix that.
You may also fix that for the 'rte_memcpy' in the fist 'if'.

> 
> 
>>>
>>> Signed-off-by: Asaf Penso <asafp at mellanox.com>
>>> ---
>>>  lib/netdev-dpdk.c | 28 ++++++++++++++--------------
>>>  1 file changed, 14 insertions(+), 14 deletions(-)
>>>
>>> diff --git a/lib/netdev-dpdk.c b/lib/netdev-dpdk.c index
>>> 4bf0ca9..5216b74 100644
>>> --- a/lib/netdev-dpdk.c
>>> +++ b/lib/netdev-dpdk.c
>>> @@ -4570,10 +4570,10 @@ netdev_dpdk_add_rte_flow_offload(struct
>> netdev *netdev,
>>>      /* Eth */
>>>      struct rte_flow_item_eth eth_spec;
>>>      struct rte_flow_item_eth eth_mask;
>>> -    memset(&eth_spec, 0, sizeof(eth_spec));
>>> -    memset(&eth_mask, 0, sizeof(eth_mask));
>>>      if (!eth_addr_is_zero(match->wc.masks.dl_src) ||
>>>          !eth_addr_is_zero(match->wc.masks.dl_dst)) {
>>> +        memset(&eth_spec, 0, sizeof(eth_spec));
>>> +        memset(&eth_mask, 0, sizeof(eth_mask));
>>>          rte_memcpy(&eth_spec.dst, &match->flow.dl_dst,
>> sizeof(eth_spec.dst));
>>>          rte_memcpy(&eth_spec.src, &match->flow.dl_src,
>> sizeof(eth_spec.src));
>>>          eth_spec.type = match->flow.dl_type; @@ -4600,9 +4600,9 @@
>>> netdev_dpdk_add_rte_flow_offload(struct netdev *netdev,
>>>      /* VLAN */
>>>      struct rte_flow_item_vlan vlan_spec;
>>>      struct rte_flow_item_vlan vlan_mask;
>>> -    memset(&vlan_spec, 0, sizeof(vlan_spec));
>>> -    memset(&vlan_mask, 0, sizeof(vlan_mask));
>>>      if (match->wc.masks.vlans[0].tci && match->flow.vlans[0].tci) {
>>> +        memset(&vlan_spec, 0, sizeof(vlan_spec));
>>> +        memset(&vlan_mask, 0, sizeof(vlan_mask));
>>>          vlan_spec.tci  = match->flow.vlans[0].tci & ~htons(VLAN_CFI);
>>>          vlan_mask.tci  = match->wc.masks.vlans[0].tci &
>>> ~htons(VLAN_CFI);
>>>
>>> @@ -4617,9 +4617,9 @@ netdev_dpdk_add_rte_flow_offload(struct
>> netdev *netdev,
>>>      uint8_t proto = 0;
>>>      struct rte_flow_item_ipv4 ipv4_spec;
>>>      struct rte_flow_item_ipv4 ipv4_mask;
>>> -    memset(&ipv4_spec, 0, sizeof(ipv4_spec));
>>> -    memset(&ipv4_mask, 0, sizeof(ipv4_mask));
>>>      if (match->flow.dl_type == htons(ETH_TYPE_IP)) {
>>> +        memset(&ipv4_spec, 0, sizeof(ipv4_spec));
>>> +        memset(&ipv4_mask, 0, sizeof(ipv4_mask));
>>>
>>>          ipv4_spec.hdr.type_of_service = match->flow.nw_tos;
>>>          ipv4_spec.hdr.time_to_live    = match->flow.nw_ttl;
>>> @@ -4662,9 +4662,9 @@ netdev_dpdk_add_rte_flow_offload(struct
>> netdev
>>> *netdev,
>>>
>>>      struct rte_flow_item_tcp tcp_spec;
>>>      struct rte_flow_item_tcp tcp_mask;
>>> -    memset(&tcp_spec, 0, sizeof(tcp_spec));
>>> -    memset(&tcp_mask, 0, sizeof(tcp_mask));
>>>      if (proto == IPPROTO_TCP) {
>>> +        memset(&tcp_spec, 0, sizeof(tcp_spec));
>>> +        memset(&tcp_mask, 0, sizeof(tcp_mask));
>>>          tcp_spec.hdr.src_port  = match->flow.tp_src;
>>>          tcp_spec.hdr.dst_port  = match->flow.tp_dst;
>>>          tcp_spec.hdr.data_off  = ntohs(match->flow.tcp_flags) >> 8;
>>> @@ -4687,9 +4687,9 @@ netdev_dpdk_add_rte_flow_offload(struct
>> netdev
>>> *netdev,
>>>
>>>      struct rte_flow_item_udp udp_spec;
>>>      struct rte_flow_item_udp udp_mask;
>>> -    memset(&udp_spec, 0, sizeof(udp_spec));
>>> -    memset(&udp_mask, 0, sizeof(udp_mask));
>>>      if (proto == IPPROTO_UDP) {
>>> +        memset(&udp_spec, 0, sizeof(udp_spec));
>>> +        memset(&udp_mask, 0, sizeof(udp_mask));
>>>          udp_spec.hdr.src_port = match->flow.tp_src;
>>>          udp_spec.hdr.dst_port = match->flow.tp_dst;
>>>
>>> @@ -4708,9 +4708,9 @@ netdev_dpdk_add_rte_flow_offload(struct
>> netdev
>>> *netdev,
>>>
>>>      struct rte_flow_item_sctp sctp_spec;
>>>      struct rte_flow_item_sctp sctp_mask;
>>> -    memset(&sctp_spec, 0, sizeof(sctp_spec));
>>> -    memset(&sctp_mask, 0, sizeof(sctp_mask));
>>>      if (proto == IPPROTO_SCTP) {
>>> +        memset(&sctp_spec, 0, sizeof(sctp_spec));
>>> +        memset(&sctp_mask, 0, sizeof(sctp_mask));
>>>          sctp_spec.hdr.src_port = match->flow.tp_src;
>>>          sctp_spec.hdr.dst_port = match->flow.tp_dst;
>>>
>>> @@ -4729,9 +4729,9 @@ netdev_dpdk_add_rte_flow_offload(struct
>> netdev
>>> *netdev,
>>>
>>>      struct rte_flow_item_icmp icmp_spec;
>>>      struct rte_flow_item_icmp icmp_mask;
>>> -    memset(&icmp_spec, 0, sizeof(icmp_spec));
>>> -    memset(&icmp_mask, 0, sizeof(icmp_mask));
>>>      if (proto == IPPROTO_ICMP) {
>>> +        memset(&icmp_spec, 0, sizeof(icmp_spec));
>>> +        memset(&icmp_mask, 0, sizeof(icmp_mask));
>>>          icmp_spec.hdr.icmp_type = (uint8_t)ntohs(match->flow.tp_src);
>>>          icmp_spec.hdr.icmp_code = (uint8_t)ntohs(match->flow.tp_dst);
>>>
>>>


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