Rename new_server_opt to server_opt

Summary:
Rename the `new_server_opt` statistics counter to `server_opt` across TPR codebase.

The "new_server_opt" counter was introduced during the rollout of TPR server optimization features. Now that the rollout is complete and this is the standard behavior, the "new" prefix is misleading and adds unnecessary verbosity.

Reviewed By: frankfeir

Differential Revision: D80952473

fbshipit-source-id: 3d24c93dcc41e3273f385261996ef3c2ecd07ba5

Author: p-shah256

katran/tpr/TPRStatsPoller.cpp

@@ -40,7 +40,7 @@ void TPRStatsPoller::setStatsCounters(const tcp_router_stats& stats) {
   setCounter("error_write_opt", stats.error_write_opt);
   setCounter("error_sys_calls", stats.error_sys_calls);
   setCounter("ignoring_due_to_kde", stats.ignoring_due_to_kde);
-  setCounter("new_server_opt", stats.new_server_opt);
+  setCounter("server_opt", stats.server_opt);
 }
 
 TPRStatsPoller::TPRStatsPoller(
@@ -158,7 +158,7 @@ TPRStatsPoller::collectTPRStats(int numCpus) {
     aggregateStats.error_write_opt += stat.error_write_opt;
     aggregateStats.error_sys_calls += stat.error_sys_calls;
     aggregateStats.ignoring_due_to_kde += stat.ignoring_due_to_kde;
-    aggregateStats.new_server_opt += stat.new_server_opt;
+    aggregateStats.server_opt += stat.server_opt;
   }
   return aggregateStats;
 }

katran/tpr/TPRTypes.h

@@ -46,7 +46,7 @@ struct tcp_router_stats {
   uint64_t error_write_opt{0};
   uint64_t error_sys_calls{0};
   uint64_t ignoring_due_to_kde{0};
-  uint64_t new_server_opt{0};
+  uint64_t server_opt{0};
 };
 
 // helper methods to constructs useful error message without boiler plate code.
@@ -95,7 +95,7 @@ inline std::ostream& operator<<(std::ostream& os, const tcp_router_stats& s) {
      << " error_server_id_zero=" << s.error_server_id_zero
      << " error_write_opt=" << s.error_write_opt
      << " error_sys_calls=" << s.error_sys_calls
-     << " new_server_opt=" << s.new_server_opt;
+     << " server_opt=" << s.server_opt;
   return os;
 }
 

katran/tpr/bpf/tcp_pkt_router_active_hdlr.h

@@ -25,7 +25,7 @@ static inline int load_tpr_opt(
   err = bpf_load_hdr_opt(skops, hdr_opt, sizeof(*hdr_opt), NO_FLAGS);
   if (err >= 0) {
     // err >= 0 means we succeeded at reading the header.
-    stat->new_server_opt++;
+    stat->server_opt++;
     return err;
   }
 

katran/tpr/bpf/tcp_pkt_router_structs.h

@@ -42,5 +42,5 @@ struct stats {
   __u64 error_sys_calls;
   __u64 ignoring_due_to_kde;
   // stats for the rollout of the new TPR server OPT
-  __u64 new_server_opt;
+  __u64 server_opt;
 };