The DLC_TRACE ioctl operation is selectable through the fp_ioctl kernel service or the ioctl subroutine. It can be called from the process environment only.
The following parameter block traces link station (LS) activity for short or long activities:
struct dlc_trace_arg
   {
   __ulong32_t  gdlc_sap_corr;   /* GDLC SAP correlator */
   __ulong32_t  gdlc_ls_corr;   /* GDLC link station correlator */
   __ulong32_t  trace_chan;   /* Trace Channel (rc of trcstart) */
   __ulong32_t  flags;   /* Trace Flags */
   };
The fields of this ioctl operation are:
| Field | Description | 
|---|---|
| gdlc_sap_corr | Contains the GDLC SAP correlator. The correlator returned by GDLC when the SAP was enabled by the user. This correlator identifies the user SAP to the GDLC protocol process. | 
| gdlc_ls_corr | Contains the GDLC LS correlator. The correlator returned by GDLC when the LS was started by the user. This correlator identifies the user LS to the GDLC protocol process. | 
| trace_chan | Specifies the trace channel number obtained from the trcstart subroutine. This field is only valid if the DLC_TRCO indicator is set active. | 
| flags |   Specifies trace flags. The following flags are supported:
 
  |