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Hi Team,</div>
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We are trying to compile and run dpdk 20.11 pipeline using clang (LLVM 5.0) compiler. We are able to compile and run the pipeline. However, we observed a lot of pkts not executing the acl lookup properly. While debugging, we found that a lot of pkts were missed
in packets out mask. This aspect was checked with the rte_table_acl_lookup function in lib/librte_table/rte_table_acl.c file.
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<div class="ContentPasted0">Here is the function:</div>
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<div class="ContentPasted0">static int</div>
<div class="ContentPasted0">rte_table_acl_lookup(</div>
<div class="ContentPasted0"> void *table,</div>
<div class="ContentPasted0"> struct rte_mbuf **pkts,</div>
<div class="ContentPasted0"> uint64_t pkts_mask,</div>
<div class="ContentPasted0"> uint64_t *lookup_hit_mask,</div>
<div class="ContentPasted0"> void **entries)</div>
<div class="ContentPasted0">{</div>
<div class="ContentPasted0"> struct rte_table_acl *acl = (struct rte_table_acl *) table;</div>
<div class="ContentPasted0"> const uint8_t *pkts_data[RTE_PORT_IN_BURST_SIZE_MAX];</div>
<div class="ContentPasted0"> uint32_t results[RTE_PORT_IN_BURST_SIZE_MAX];</div>
<div class="ContentPasted0"> uint64_t pkts_out_mask;</div>
<div class="ContentPasted0"> uint32_t n_pkts, i, j;</div>
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<div class="ContentPasted0"> __rte_unused uint32_t n_pkts_in = __builtin_popcountll(pkts_mask);</div>
<div class="ContentPasted0"> RTE_TABLE_ACL_STATS_PKTS_IN_ADD(acl, n_pkts_in);</div>
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<div class="ContentPasted0"> /* Input conversion */</div>
<div class="ContentPasted0"> for (i = 0, j = 0; i < (uint32_t)(RTE_PORT_IN_BURST_SIZE_MAX -</div>
<div class="ContentPasted0"> __builtin_clzll(pkts_mask)); i++) {</div>
<div class="ContentPasted0"> uint64_t pkt_mask = 1LLU << i;</div>
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<div class="ContentPasted0"> if (pkt_mask & pkts_mask) {</div>
<div class="ContentPasted0"> pkts_data[j] = rte_pktmbuf_mtod(pkts[i], uint8_t *);</div>
<div class="ContentPasted0"> j++;</div>
<div class="ContentPasted0"> }</div>
<div class="ContentPasted0"> }</div>
<div class="ContentPasted0"> n_pkts = j;</div>
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<div class="ContentPasted0"> </div>
<div class="ContentPasted0"> /* Low-level ACL table lookup */</div>
<div class="ContentPasted0"> if (acl->ctx != NULL)</div>
<div class="ContentPasted0"> rte_acl_classify(acl->ctx, pkts_data, results, n_pkts, 1);</div>
<div class="ContentPasted0"> else</div>
<div class="ContentPasted0"> n_pkts = 0;</div>
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<div class="ContentPasted0"> </div>
<div class="ContentPasted0"> /* Output conversion */</div>
<div class="ContentPasted0"> pkts_out_mask = 0;</div>
<div class="ContentPasted0"> for (i = 0; i < n_pkts; i++) {</div>
<div class="ContentPasted0"> uint32_t action_table_pos = results[i];</div>
<div class="ContentPasted0"> uint32_t pkt_pos = __builtin_ctzll(pkts_mask);</div>
<div class="ContentPasted0"> uint64_t pkt_mask = 1LLU << pkt_pos;</div>
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<div class="ContentPasted0"> pkts_mask &= ~pkt_mask;</div>
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<div class="ContentPasted0"> if (action_table_pos != 0) {</div>
<div class="ContentPasted0"> pkts_out_mask |= pkt_mask;</div>
<div class="ContentPasted0"> entries[pkt_pos] = (void *)</div>
<div class="ContentPasted0">&acl->memory[action_table_pos *</div>
<div class="ContentPasted0"> acl->entry_size];</div>
<div class="ContentPasted0"> rte_prefetch0(entries[pkt_pos]);</div>
<div class="ContentPasted0"> }</div>
<div class="ContentPasted0"> }</div>
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<div class="ContentPasted0"> *lookup_hit_mask = pkts_out_mask;</div>
<div class="ContentPasted0"> RTE_TABLE_ACL_STATS_PKTS_LOOKUP_MISS(acl, n_pkts_in - __builtin_popcountll(pkts_out_mask));</div>
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<div class="ContentPasted0"> return 0;</div>
<div class="ContentPasted0">}</div>
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Can you provide some suggestions to avoid this issue and enable acl to run without functionality loss?<br>
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Thanks and regards,</div>
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R. Sundararaman</div>
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