[Error debug] PHV allocation was not successful

Hello, does anyone know how to solve the error: PHV allocation was not successful. I am trying to convert bmv2 program to tofino. Part of the code and error prompts is attached below. Let me know if you need more info. I very appreciate your help.

struct my_ingress_metadata_t {
bit<2> meter_color;
bit<32> weight;
bit<32> threshold;
bit<32> plr;
bit<32> current_rate;
bit<32> demand;
bit<32> flow_h1;
bit<48> flow_time;
tPort_t destinationPort;
bit<16> next_rate_tbl;
bit<16> next_demand_tbl;
bit<10> meter_index;
bit<32> flow_byte_counter;
bit<32> prev_flow_byte_counter;
bit<32> flow_last_time_stamp_32;
bit<32> flow_last_time_stamp_16;
bit<32> delta;
bit<48> time_diff;

control Ingress(
    /* User */
    inout my_ingress_headers_t                       hdr,
    inout my_ingress_metadata_t                      meta,
    /* Intrinsic */
    in    ingress_intrinsic_metadata_t               ig_intr_md,
    in    ingress_intrinsic_metadata_from_parser_t   ig_prsr_md,
    inout ingress_intrinsic_metadata_for_deparser_t  ig_dprsr_md,
    inout ingress_intrinsic_metadata_for_tm_t        ig_tm_md)

    Register<bit<32>, bit<REGISTER_CELL_WIDTH>>(REGISTER_SIZE_TOTAL, 0) flow_payload_counter;
    RegisterAction<bit<32>, bit<32>, bit<32>>(flow_payload_counter) write_flow_payload_counter = {
        void apply(inout bit<32> write_value){
            write_value = meta.flow_byte_counter;

    apply {
          /* write to register */
          meta.flow_byte_counter  = meta.flow_byte_counter + (bit<32>)hdr.ipv4.totalLen;

error prompts:

========================= make.log =========================
error: PHV allocation was not successful

3 field slices remain unallocated

The following fields were not allocated: 




Number of P4 compiler-proper ERRORs: 2

Number of P4 compiler-proper WARNINGs: 11

Number of errors exceeded set maximum of 1

make[2]: *** [CMakeFiles/l4_learning_tna-tofino.dir/build.make:73: l4_learning_tna/tofino/bf-rt.json] Error 3

make[2]: *** Deleting file 'l4_learning_tna/tofino/bf-rt.json'

make[1]: *** [CMakeFiles/Makefile2:166: CMakeFiles/l4_learning_tna-tofino.dir/all] Error 2

make: *** [Makefile:136: all] Error 2

========================= make.log =========================

Dear @HangHu,

Welcome to the forum! I

You can find a lot of useful information on this forum, especially if you use its search function ( :mag:). For example, a simple search on the “tofino” keyword will immediately produce this post , which contains the necessary recommendations.

Also, if you you haven’t done it already, I’d highly recommend you attend Intel Connectivity Academy by P4ica courses.

Happy hacking,

Dear Vladimir,

Thank you very much for your suggestions. Also, my colleague has enrolled in the upcoming P4 course.

Hello Hang,

I am really glad you followed the advice and I hope it was helpful, was it not?

For the benefit of those who might find themselves in a similar situation, we can now report that you reached out via ICRP forum (as was suggested), where you promptly received a specific recommendation that solved the issue.

Happy hacking,