The problem of using register

[bin NIU]

Hello :

  Recently , I want to implement a p4 application using smartnic , in this application I want to choose one out of every 100 packets to modify and the others are send out normally.

  But I found I cant not to choose the packet to modify.

  The following is the code

  

header_type ethernet_t {

    fields {

        dstAddr : 48;

        srcAddr : 48;

        etherType : 16;

    }

}

header_type ipv4_t {

    fields {

        version : 4;

        ihl : 4;

        //diffserv : 8;

        dscp : 6;

        ecn : 2;

        totalLen : 16;

        identification : 16;

        flags : 3;

        fragOffset : 13;

        ttl : 8;

        protocol : 8;

        hdrChecksum : 16;

        srcAddr : 32;

        dstAddr: 32;

    }

}

parser start {

    return parse_ethernet;

}

/*

 * Ethernet

 */

#define ETHERTYPE_IPV4 0x0800

header ethernet_t ethernet;

header ipv4_t ipv4;

parser parse_ethernet {

    extract(ethernet);

    return select(latest.etherType) {

        ETHERTYPE_IPV4 : parse_ipv4;

        default : ingress;

    }

}

parser parse_ipv4 {

    extract(ipv4);

    //set_metadata(tcp_length_meta.tcpLength,latest.totalLen - 20);

    return ingress;

}

action do_forward(espec) {

    modify_field(standard_metadata.egress_spec, espec);

    

}

action do_drop() {

    drop();

}

table tbl_forward {

    reads {

        standard_metadata.ingress_port : exact;

        //ipv4.dstAddr                   : ternary;

    }

    actions {

        do_forward;

        do_drop;

    }

    size : 4;

}

@pragma netro reglocked register

register hh_reg {

    width : 32;

    instance_count : 1;

}

action load_count_act() {

    register_read(load.load,hh_reg,0);

    register_write(hh_reg,0,load.load + 1);   

}

action load_rewrite() {

    register_write(hh_reg,0,0);

}

table tbl_load_count_act {

    actions {

        load_count_act;

    }

    

}

table tbl_load_rewrite {

    actions {

        load_rewrite;

    }

}

action test_count() {

    modify_field(ipv4.srcAddr,0);

}

table tbl_test {

    actions {

        test_count;

    }

}

control ingress {

    apply(tbl_forward);

    

    

}

control egress {

    

    apply(tbl_load_count_act);

    if (load.load == 100) {

        apply(tbl_load_rewrite);

        apply(tbl_test);

    }

}

[David George]

Hi

This is due to the flowcache - the devtools user guide has a blurb about this. The register change isn't effecting the cached lookups for the flow.

Regards,

David

[bin NIU]

Hi:

Thanks for your reply , and Is there any way to make the cache invalid periodically? 

Regards

Bin

在 2018年10月29日星期一 UTC+8下午2:34:36，David George写道：

[Gerhard de Klerk]

Hi Bin, 

The flow cache should time out after a while, but you can disable the flowcache all together. 
This will reduce performance but should provide the functionality that you are looking for.

Best regards,
Gerhard

--
You received this message because you are subscribed to the Google Groups "open-nfp" group.
To unsubscribe from this group and stop receiving emails from it, send an email to open-nfp+u...@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/open-nfp/5a9683df-f896-4f69-9452-7d702495f66c%40googlegroups.com.
For more options, visit https://groups.google.com/d/optout.

[Abhishek Dixit]

hey, can you please tell me which file to modify to disable the lookup cache? I don't use GUI.