While running the application, set the environment variable
                PCL_EVENT or TAU_METRICS
                , to specify which hardware performance counter TAU should
                use while profiling the application.
         
| ![[Note]](note.png) | Note | 
|---|---|
|  By default, only one counter is tracked at a time.  To track
                            more than one counter use  | 
To select floating point instructions for profiling using
                PAPI, you would:
         
% configure -papi=/usr/local/packages/papi-3.5.0
% make clean install
% cd examples/papi
% setenv TAU_METRICS PAPI_FP_INS
% a.out
    
                  In addition to the following events, you can use native events (see
                  papi_native) on a given CPU by setting
                  TAU_ to
                  PAPI_NATIVE_<event>.  For example:
                  
         
% setenv PAPI_NATIVE PAPI_NATIVE_PM_BIQ_IDU_FULL_CYC
% a.out
      
By default PAPI will profile events in all domains
                (users space, kernel, hypervisor, etc). You can restrict the set of domains
                for papi event profiling by using the
                TAU_PAPI_DOMAIN environment variable with these values (in
                a colon separated list, if desired): PAPI_DOM_USER,
                   PAPI_DOM_KERNEL, PAPI_DOM_SUPERVISOR, and
                PAPI_DOM_OTHER like thus:
                
         
% setenv TAU_PAPI_DOMAIN PAPI_DOM_SUPERVISOR:PAPI_DOM_OTHER