static void
show_event_info(char *name, unsigned int idx)
{
pfmlib_regmask_t cnt, impl_cnt;
char *desc;
unsigned int n1, n2, i, c;
int code, prev_code = 0, first = 1;
int ret;
pfm_get_event_counters(idx, &cnt);
pfm_get_num_counters(&n2);
pfm_get_impl_counters(&impl_cnt);
n1 = n2;
printf("#-----------------------------\n"
"Name : %s\n",
name);
pfm_get_event_description(idx, &desc);
printf("Desc : %s\n", desc);
free(desc);
printf("Code :");
for (i=0; n1; i++) {
if (pfm_regmask_isset(&impl_cnt, i))
n1--;
if (pfm_regmask_isset(&cnt, i)) {
pfm_get_event_code_counter(idx,i,&code);
if (first == 1 || code != prev_code) {
printf(" 0x%x", code);
first = 0;
}
prev_code = code;
}
}
putchar('\n');
n1 = n2;
printf("Counters : [ ");
for (i=0; n1; i++) {
if (pfm_regmask_isset(&impl_cnt, i))
n1--;
if (pfm_regmask_isset(&cnt, i))
printf("%d ", i);
}
puts("]");
pfm_get_num_event_masks(idx, &n1);
for (i = 0; i < n1; i++) {
ret = pfm_get_event_mask_name(idx, i, name, max_len+1);
if (ret != PFMLIB_SUCCESS)
continue;
pfm_get_event_mask_description(idx, i, &desc);
pfm_get_event_mask_code(idx, i, &c);
printf("Umask-%02u : 0x%02x : [%s] : %s\n", i, c, name, desc);
free(desc);
}
}
static int setup_preset_term(int *native, pfmlib_event_t *event)
{
/* It seems this could be greatly simplified. If impl_cnt is non-zero,
the event lives on a counter. Therefore the entire routine could be:
if (impl_cnt!= 0) encode_native_event.
Am I wrong?
*/
pfmlib_regmask_t impl_cnt, evnt_cnt;
unsigned int n;
int j, ret;
/* find out which counters it lives on */
if ((ret = pfm_get_event_counters(event->event,&evnt_cnt)) != PFMLIB_SUCCESS)
{
PAPIERROR("pfm_get_event_counters(%d,%p): %s",event->event,&evnt_cnt,pfm_strerror(ret));
return(PAPI_EBUG);
}
if ((ret = pfm_get_impl_counters(&impl_cnt)) != PFMLIB_SUCCESS)
{
PAPIERROR("pfm_get_impl_counters(%p): %s", &impl_cnt, pfm_strerror(ret));
return(PAPI_EBUG);
}
/* Make sure this event lives on some counter, if so, put in the description. If not, BUG */
if ((ret = pfm_get_num_counters(&n)) != PFMLIB_SUCCESS)
{
PAPIERROR("pfm_get_num_counters(%d): %s", n, pfm_strerror(ret));
return(PAPI_EBUG);
}
for (j=0;n;j++)
{
if (pfm_regmask_isset(&impl_cnt, j))
{
n--;
if (pfm_regmask_isset(&evnt_cnt,j))
{
*native = encode_native_event(event->event,event->num_masks,event->unit_masks);
return(PAPI_OK);
}
}
}
PAPIERROR("PAPI preset 0x%08x PFM event %d did not have any available counters", event->event, j);
return(PAPI_ENOEVNT);
}
int
mainloop(char **arg)
{
ctx_arg_t ctx;
pfmlib_input_param_t inp;
pfmlib_output_param_t outp;
pfarg_reg_t pd[NUM_PMDS];
pfarg_reg_t pc[NUM_PMCS];
pfarg_load_t load_args;
pfm_msg_t msg;
unsigned long ovfl_count = 0UL;
unsigned long sample_period;
unsigned long smpl_pmd_mask = 0UL;
pid_t pid;
int status, ret, fd;
unsigned int i, num_counters;
/*
* intialize all locals
*/
memset(&ctx, 0, sizeof(ctx));
memset(&inp,0, sizeof(inp));
memset(&outp,0, sizeof(outp));
memset(pd, 0, sizeof(pd));
memset(pc, 0, sizeof(pc));
/*
* locate events
*/
pfm_get_num_counters(&num_counters);
if (pfm_get_cycle_event(&inp.pfp_events[0]) != PFMLIB_SUCCESS)
fatal_error("cannot find cycle event\n");
if (pfm_get_inst_retired_event(&inp.pfp_events[1]) != PFMLIB_SUCCESS)
fatal_error("cannot find inst retired event\n");
i = 2;
if (i > num_counters) {
i = num_counters;
printf("too many events provided (max=%d events), using first %d event(s)\n", num_counters, i);
}
/*
* set the privilege mode:
* PFM_PLM3 : user level
* PFM_PLM0 : kernel level
*/
inp.pfp_dfl_plm = PFM_PLM3;
/*
* how many counters we use
*/
inp.pfp_event_count = i;
/*
* let the library figure out the values for the PMCS
*/
if ((ret=pfm_dispatch_events(&inp, NULL, &outp, NULL)) != PFMLIB_SUCCESS) {
fatal_error("cannot configure events: %s\n", pfm_strerror(ret));
}
/*
* Now prepare the argument to initialize the PMDs and PMCS.
* We must pfp_pmc_count to determine the number of PMC to intialize.
* We must use pfp_event_count to determine the number of PMD to initialize.
* Some events causes extra PMCs to be used, so pfp_pmc_count may be >= pfp_event_count.
*
* This step is new compared to libpfm-2.x. It is necessary because the library no
* longer knows about the kernel data structures.
*/
for (i=0; i < outp.pfp_pmc_count; i++) {
pc[i].reg_num = outp.pfp_pmcs[i].reg_num;
pc[i].reg_value = outp.pfp_pmcs[i].reg_value;
}
/*
* the PMC controlling the event ALWAYS come first, that's why this loop
* is safe even when extra PMC are needed to support a particular event.
*/
for (i=0; i < inp.pfp_event_count; i++) {
pd[i].reg_num = pc[i].reg_num;
/* build sampling mask */
smpl_pmd_mask |= 1UL << pc[i].reg_num;
}
printf("smpl_pmd_mask=0x%lx\n", smpl_pmd_mask);
/*
* now we indicate what to record when each counter overflows.
* In our case, we only have one sampling period and it is set for the
* first event. Here we indicate that when the sampling period expires
* then we want to record the value of all the other counters.
*
* We exclude the first counter in this case.
*/
smpl_pmd_mask &= ~(1UL << pc[0].reg_num);
pc[0].reg_smpl_pmds[0] = smpl_pmd_mask;
/*
* we our sampling counter overflow, we want to be notified.
* The notification will come ONLY when the sampling buffer
* becomes full.
*
* We also activate randomization of the sampling period.
*/
pc[0].reg_flags |= PFM_REGFL_OVFL_NOTIFY | PFM_REGFL_RANDOM;
/*
* we also want to reset the other PMDs on
* every overflow. If we do not set
* this, the non-overflowed counters
* will be untouched.
*/
pc[0].reg_reset_pmds[0] |= smpl_pmd_mask;
sample_period = 1000000UL;
pd[0].reg_value = (~0) - sample_period + 1;
pd[0].reg_short_reset = (~0) - sample_period + 1;
pd[0].reg_long_reset = (~0) - sample_period + 1;
/*
* setup randomization parameters, we allow a range of up to +256 here.
*/
pd[0].reg_random_seed = 5;
pd[0].reg_random_mask = 0xff;
printf("programming %u PMCS and %u PMDS\n", outp.pfp_pmc_count, inp.pfp_event_count);
/*
* prepare context structure.
*
* format specific parameters MUST be concatenated to the regular
* pfarg_context_t structure. For convenience, the default sampling
* format provides a data structure that already combines the pfarg_context_t
* with what is needed fot this format.
*/
/*
* We initialize the format specific information.
* The format is identified by its UUID which must be copied
* into the ctx_buf_fmt_id field.
*/
memcpy(ctx.ctx_arg.ctx_smpl_buf_id, buf_fmt_id, sizeof(pfm_uuid_t));
/*
* the size of the buffer is indicated in bytes (not entries).
*
* The kernel will record into the buffer up to a certain point.
* No partial samples are ever recorded.
*/
ctx.buf_arg.buf_size = 8192;
/*
* now create our perfmon context.
*/
if (perfmonctl(0, PFM_CREATE_CONTEXT, &ctx, 1) == -1 ) {
if (errno == ENOSYS) {
fatal_error("Your kernel does not have performance monitoring support!\n");
}
fatal_error("Can't create PFM context %s\n", strerror(errno));
}
/*
* extract the file descriptor we will use to
* identify this newly created context
*/
fd = ctx.ctx_arg.ctx_fd;
/*
* retrieve the virtual address at which the sampling
* buffer has been mapped
*/
buf_addr = ctx.ctx_arg.ctx_smpl_vaddr;
printf("context [%d] buffer mapped @%p\n", fd, buf_addr);
/*
* Now program the registers
*/
if (perfmonctl(fd, PFM_WRITE_PMCS, pc, outp.pfp_pmc_count) == -1) {
fatal_error("perfmonctl error PFM_WRITE_PMCS errno %d\n",errno);
}
/*
* initialize the PMDs
*/
if (perfmonctl(fd, PFM_WRITE_PMDS, pd, inp.pfp_event_count) == -1) {
fatal_error("perfmonctl error PFM_WRITE_PMDS errno %d\n",errno);
}
/*
* Create the child task
*/
if ((pid=fork()) == -1) fatal_error("Cannot fork process\n");
/*
* In order to get the PFM_END_MSG message, it is important
* to ensure that the child task does not inherit the file
* descriptor of the context. By default, file descriptor
* are inherited during exec(). We explicitely close it
* here. We could have set it up through fcntl(FD_CLOEXEC)
* to achieve the same thing.
*/
if (pid == 0) {
close(fd);
child(arg);
}
/*
* wait for the child to exec
*/
waitpid(pid, &status, WUNTRACED);
/*
* process is stopped at this point
*/
if (WIFEXITED(status)) {
warning("task %s [%d] exited already status %d\n", arg[0], pid, WEXITSTATUS(status));
goto terminate_session;
}
/*
* attach context to stopped task
*/
load_args.load_pid = pid;
if (perfmonctl(fd, PFM_LOAD_CONTEXT, &load_args, 1) == -1) {
fatal_error("perfmonctl error PFM_LOAD_CONTEXT errno %d\n",errno);
}
/*
* activate monitoring for stopped task.
* (nothing will be measured at this point
*/
if (perfmonctl(fd, PFM_START, NULL, 0) == -1) {
fatal_error(" perfmonctl error PFM_START errno %d\n",errno);
}
/*
* detach child. Side effect includes
* activation of monitoring.
*/
ptrace(PTRACE_DETACH, pid, NULL, 0);
/*
* core loop
*/
for(;;) {
/*
* wait for overflow/end notification messages
*/
ret = read(fd, &msg, sizeof(msg));
if (ret == -1) {
fatal_error("cannot read perfmon msg: %s\n", strerror(errno));
}
switch(msg.type) {
case PFM_MSG_OVFL: /* the sampling buffer is full */
process_smpl_buf(fd, smpl_pmd_mask, 1);
ovfl_count++;
break;
case PFM_MSG_END: /* monitored task terminated */
printf("task terminated\n");
goto terminate_session;
default: fatal_error("unknown message type %d\n", msg.type);
}
}
terminate_session:
/*
* cleanup child
*/
waitpid(pid, &status, 0);
/*
* check for any leftover samples
*/
process_smpl_buf(fd, smpl_pmd_mask, 0);
/*
* destroy perfmon context
*/
close(fd);
printf("%lu samples collected in %lu buffer overflows\n", collect_samples, ovfl_count);
return 0;
}
int
_papi_libpfm_init(papi_vector_t *my_vector, int cidx) {
int retval;
unsigned int ncnt;
unsigned int version;
char pmu_name[PAPI_MIN_STR_LEN];
/* The following checks the version of the PFM library
against the version PAPI linked to... */
SUBDBG( "pfm_initialize()\n" );
if ( ( retval = pfm_initialize( ) ) != PFMLIB_SUCCESS ) {
PAPIERROR( "pfm_initialize(): %s", pfm_strerror( retval ) );
return PAPI_ESYS;
}
/* Get the libpfm3 version */
SUBDBG( "pfm_get_version(%p)\n", &version );
if ( pfm_get_version( &version ) != PFMLIB_SUCCESS ) {
PAPIERROR( "pfm_get_version(%p): %s", version, pfm_strerror( retval ) );
return PAPI_ESYS;
}
/* Set the version */
sprintf( my_vector->cmp_info.support_version, "%d.%d",
PFM_VERSION_MAJOR( version ), PFM_VERSION_MINOR( version ) );
/* Complain if the compiled-against version doesn't match current version */
if ( PFM_VERSION_MAJOR( version ) != PFM_VERSION_MAJOR( PFMLIB_VERSION ) ) {
PAPIERROR( "Version mismatch of libpfm: compiled %#x vs. installed %#x\n",
PFM_VERSION_MAJOR( PFMLIB_VERSION ),
PFM_VERSION_MAJOR( version ) );
return PAPI_ESYS;
}
/* Always initialize globals dynamically to handle forks properly. */
_perfmon2_pfm_pmu_type = -1;
/* Opened once for all threads. */
SUBDBG( "pfm_get_pmu_type(%p)\n", &_perfmon2_pfm_pmu_type );
if ( pfm_get_pmu_type( &_perfmon2_pfm_pmu_type ) != PFMLIB_SUCCESS ) {
PAPIERROR( "pfm_get_pmu_type(%p): %s", _perfmon2_pfm_pmu_type,
pfm_strerror( retval ) );
return PAPI_ESYS;
}
pmu_name[0] = '\0';
if ( pfm_get_pmu_name( pmu_name, PAPI_MIN_STR_LEN ) != PFMLIB_SUCCESS ) {
PAPIERROR( "pfm_get_pmu_name(%p,%d): %s", pmu_name, PAPI_MIN_STR_LEN,
pfm_strerror( retval ) );
return PAPI_ESYS;
}
SUBDBG( "PMU is a %s, type %d\n", pmu_name, _perfmon2_pfm_pmu_type );
/* Setup presets */
retval = _papi_load_preset_table( pmu_name, _perfmon2_pfm_pmu_type, cidx );
if ( retval )
return retval;
/* Fill in cmp_info */
SUBDBG( "pfm_get_num_events(%p)\n", &ncnt );
if ( ( retval = pfm_get_num_events( &ncnt ) ) != PFMLIB_SUCCESS ) {
PAPIERROR( "pfm_get_num_events(%p): %s\n", &ncnt,
pfm_strerror( retval ) );
return PAPI_ESYS;
}
SUBDBG( "pfm_get_num_events: %d\n", ncnt );
my_vector->cmp_info.num_native_events = ncnt;
num_native_events = ncnt;
pfm_get_num_counters( ( unsigned int * ) &my_vector->cmp_info.num_cntrs );
SUBDBG( "pfm_get_num_counters: %d\n", my_vector->cmp_info.num_cntrs );
if ( _papi_hwi_system_info.hw_info.vendor == PAPI_VENDOR_INTEL ) {
/* Pentium4 */
if ( _papi_hwi_system_info.hw_info.cpuid_family == 15 ) {
PAPI_NATIVE_EVENT_AND_MASK = 0x000000ff;
PAPI_NATIVE_UMASK_AND_MASK = 0x0fffff00;
PAPI_NATIVE_UMASK_SHIFT = 8;
/* Itanium2 */
} else if ( _papi_hwi_system_info.hw_info.cpuid_family == 31 ||
_papi_hwi_system_info.hw_info.cpuid_family == 32 ) {
PAPI_NATIVE_EVENT_AND_MASK = 0x00000fff;
PAPI_NATIVE_UMASK_AND_MASK = 0x0ffff000;
PAPI_NATIVE_UMASK_SHIFT = 12;
}
}
return PAPI_OK;
}
int
parent(char **arg)
{
pfmlib_input_param_t inp;
pfmlib_output_param_t outp;
pfarg_context_t ctx[1];
pfarg_reg_t pc[NUM_PMCS];
pfarg_reg_t pd[NUM_PMDS];
pfarg_load_t load_args;
unsigned int i, num_counters;
int status, ret;
int ctx_fd;
pid_t pid;
char name[MAX_EVT_NAME_LEN];
memset(pc, 0, sizeof(ctx));
memset(pd, 0, sizeof(ctx));
memset(ctx, 0, sizeof(ctx));
memset(&inp,0, sizeof(inp));
memset(&outp,0, sizeof(outp));
memset(&load_args,0, sizeof(load_args));
pfm_get_num_counters(&num_counters);
if (pfm_get_cycle_event(&inp.pfp_events[0]) != PFMLIB_SUCCESS)
fatal_error("cannot find cycle event\n");
if (pfm_get_inst_retired_event(&inp.pfp_events[1]) != PFMLIB_SUCCESS)
fatal_error("cannot find inst retired event\n");
i = 2;
if (num_counters < i) {
i = num_counters;
printf("too many events provided (max=%d events), using first %d event(s)\n", num_counters, i);
}
/*
* set the privilege mode:
* PFM_PLM3 : user level
* PFM_PLM0 : kernel level
*/
inp.pfp_dfl_plm = PFM_PLM3;
/*
* how many counters we use
*/
inp.pfp_event_count = i;
/*
* let the library figure out the values for the PMCS
*/
if ((ret=pfm_dispatch_events(&inp, NULL, &outp, NULL)) != PFMLIB_SUCCESS) {
fatal_error("cannot configure events: %s\n", pfm_strerror(ret));
}
/*
* now create a context. we will later attach it to the task we are creating.
*/
if (perfmonctl(0, PFM_CREATE_CONTEXT, ctx, 1) == -1) {
if (errno == ENOSYS) {
fatal_error("Your kernel does not have performance monitoring support!\n");
}
fatal_error("Can't create PFM context %s\n", strerror(errno));
}
/*
* extract the identifier for our context
*/
ctx_fd = ctx[0].ctx_fd;
/*
* Now prepare the argument to initialize the PMDs and PMCS.
* We must pfp_pmc_count to determine the number of PMC to intialize.
* We must use pfp_event_count to determine the number of PMD to initialize.
* Some events causes extra PMCs to be used, so pfp_pmc_count may be >= pfp_event_count.
*
* This step is new compared to libpfm-2.x. It is necessary because the library no
* longer knows about the kernel data structures.
*/
for (i=0; i < outp.pfp_pmc_count; i++) {
pc[i].reg_num = outp.pfp_pmcs[i].reg_num;
pc[i].reg_value = outp.pfp_pmcs[i].reg_value;
}
/*
* the PMC controlling the event ALWAYS come first, that's why this loop
* is safe even when extra PMC are needed to support a particular event.
*/
for (i=0; i < inp.pfp_event_count; i++) {
pd[i].reg_num = pc[i].reg_num;
}
/*
* Now program the registers
*
* We don't use the save variable to indicate the number of elements passed to
* the kernel because, as we said earlier, pc may contain more elements than
* the number of events we specified, i.e., contains more thann counting monitors.
*/
if (perfmonctl(ctx_fd, PFM_WRITE_PMCS, pc, outp.pfp_pmc_count) == -1) {
fatal_error("perfmonctl error PFM_WRITE_PMCS errno %d\n",errno);
}
if (perfmonctl(ctx_fd, PFM_WRITE_PMDS, pd, inp.pfp_event_count) == -1) {
fatal_error("perfmonctl error PFM_WRITE_PMDS errno %d\n",errno);
}
/*
* Create the child task
*/
if ((pid=fork()) == -1) fatal_error("Cannot fork process\n");
/*
* and launch the child code
*/
if (pid == 0) exit(child(arg));
/*
* wait for the child to exec
*/
waitpid(pid, &status, WUNTRACED);
/*
* check if process exited early
*/
if (WIFEXITED(status)) {
fatal_error("command %s exited too early with status %d\n", arg[0], WEXITSTATUS(status));
}
/*
* the task is stopped at this point
*/
/*
* now we load (i.e., attach) the context to ourself
*/
load_args.load_pid = pid;
if (perfmonctl(ctx_fd, PFM_LOAD_CONTEXT, &load_args, 1) == -1) {
fatal_error("perfmonctl error PFM_LOAD_CONTEXT errno %d\n",errno);
}
/*
* activate monitoring. The task is still STOPPED at this point. Monitoring
* will not take effect until the execution of the task is resumed.
*/
if (perfmonctl(ctx_fd, PFM_START, NULL, 0) == -1) {
fatal_error("perfmonctl error PFM_START errno %d\n",errno);
}
/*
* now resume execution of the task, effectively activating
* monitoring.
*/
ptrace(PTRACE_DETACH, pid, NULL, 0);
/*
* now the task is running
*/
/*
* simply wait for completion
*/
waitpid(pid, &status, 0);
/*
* the task has disappeared at this point but our context is still
* present and contains all the latest counts.
*/
/*
* now simply read the results.
*/
if (perfmonctl(ctx_fd, PFM_READ_PMDS, pd, inp.pfp_event_count) == -1) {
fatal_error("perfmonctl error READ_PMDS errno %d\n",errno);
return -1;
}
/*
* print the results
*
* It is important to realize, that the first event we specified may not
* be in PMD4. Not all events can be measured by any monitor. That's why
* we need to use the pc[] array to figure out where event i was allocated.
*
*/
for (i=0; i < inp.pfp_event_count; i++) {
pfm_get_full_event_name(&inp.pfp_events[i], name, MAX_EVT_NAME_LEN);
printf("PMD%u %20"PRIu64" %s\n",
pd[i].reg_num,
pd[i].reg_value,
name);
}
/*
* free the context
*/
close(ctx_fd);
return 0;
}
int
main(int argc, char **argv)
{
char **p;
int i, ret;
pid_t pid = getpid();
pfmlib_param_t evt;
pfarg_reg_t pd[NUM_PMDS];
pfarg_context_t ctx[1];
pfmlib_options_t pfmlib_options;
/*
* Initialize pfm library (required before we can use it)
*/
if (pfm_initialize() != PFMLIB_SUCCESS) {
printf("Can't initialize library\n");
exit(1);
}
/*
* check that the user did not specify too many events
*/
if (argc-1 > pfm_get_num_counters()) {
printf("Too many events specified\n");
exit(1);
}
/*
* pass options to library (optional)
*/
memset(&pfmlib_options, 0, sizeof(pfmlib_options));
pfmlib_options.pfm_debug = 0; /* set to 1 for debug */
pfm_set_options(&pfmlib_options);
memset(pd, 0, sizeof(pd));
memset(ctx, 0, sizeof(ctx));
/*
* prepare parameters to library. we don't use any Itanium
* specific features here. so the pfp_model is NULL.
*/
memset(&evt,0, sizeof(evt));
/*
* be nice to user!
*/
p = argc > 1 ? argv+1 : event_list;
for (i=0; *p ; i++, p++) {
if (pfm_find_event(*p, &evt.pfp_events[i].event) != PFMLIB_SUCCESS) {
fatal_error("Cannot find %s event\n", *p);
}
}
/*
* set the default privilege mode for all counters:
* PFM_PLM3 : user level only
*/
evt.pfp_dfl_plm = PFM_PLM3;
/*
* how many counters we use
*/
evt.pfp_event_count = i;
/*
* let the library figure out the values for the PMCS
*/
if ((ret=pfm_dispatch_events(&evt)) != PFMLIB_SUCCESS) {
fatal_error("cannot configure events: %s\n", pfm_strerror(ret));
}
/*
* for this example, we have decided not to get notified
* on counter overflows and the monitoring is not to be inherited
* in derived tasks.
*/
ctx[0].ctx_flags = PFM_FL_INHERIT_NONE;
/*
* now create the context for self monitoring/per-task
*/
if (perfmonctl(pid, PFM_CREATE_CONTEXT, ctx, 1) == -1 ) {
if (errno == ENOSYS) {
fatal_error("Your kernel does not have performance monitoring support!\n");
}
fatal_error("Can't create PFM context %s\n", strerror(errno));
}
/*
* Must be done before any PMD/PMD calls (unfreeze PMU). Initialize
* PMC/PMD to safe values. psr.up is cleared.
*/
if (perfmonctl(pid, PFM_ENABLE, NULL, 0) == -1) {
fatal_error("perfmonctl error PFM_ENABLE errno %d\n",errno);
}
/*
* Now prepare the argument to initialize the PMDs.
* the memset(pd) initialized the entire array to zero already, so
* we just have to fill in the register numbers from the pc[] array.
*/
for (i=0; i < evt.pfp_event_count; i++) {
pd[i].reg_num = evt.pfp_pc[i].reg_num;
}
/*
* Now program the registers
*
* We don't use the save variable to indicate the number of elements passed to
* the kernel because, as we said earlier, pc may contain more elements than
* the number of events we specified, i.e., contains more thann coutning monitors.
*/
if (perfmonctl(pid, PFM_WRITE_PMCS, evt.pfp_pc, evt.pfp_pc_count) == -1) {
fatal_error("perfmonctl error PFM_WRITE_PMCS errno %d\n",errno);
}
if (perfmonctl(pid, PFM_WRITE_PMDS, pd, evt.pfp_event_count) == -1) {
{int i; for(i=0; i < evt.pfp_event_count; i++) printf("pmd%d: 0x%x\n", i, pd[i].reg_flags);}
fatal_error("perfmonctl error PFM_WRITE_PMDS errno %d\n",errno);
}
/*
* Let's roll now
*/
pfm_start();
noploop(10000000);
pfm_stop();
/*
* now read the results
*/
if (perfmonctl(pid, PFM_READ_PMDS, pd, evt.pfp_event_count) == -1) {
fatal_error( "perfmonctl error READ_PMDS errno %d\n",errno);
return -1;
}
/*
* print the results
*
* It is important to realize, that the first event we specified may not
* be in PMD4. Not all events can be measured by any monitor. That's why
* we need to use the pc[] array to figure out where event i was allocated.
*
*/
for (i=0; i < evt.pfp_event_count; i++) {
char *name;
pfm_get_event_name(evt.pfp_events[i].event, &name);
printf("PMD%u %20lu %s\n",
pd[i].reg_num,
pd[i].reg_value,
name);
}
/*
* let's stop this now
*/
if (perfmonctl(pid, PFM_DESTROY_CONTEXT, NULL, 0) == -1) {
fatal_error( "child: perfmonctl error PFM_DESTROY errno %d\n",errno);
}
return 0;
}
int
parent(pid_t pid, unsigned long delay)
{
pfmlib_input_param_t inp;
pfmlib_output_param_t outp;
pfarg_pmr_t pc[NUM_PMCS];
pfarg_pmr_t pd[NUM_PMDS];
pfarg_sinfo_t sif;
struct pollfd pollfd;
pfarg_msg_t msg;
unsigned int i, num_counters;
int status, ret;
int ctx_fd;
char name[MAX_EVT_NAME_LEN];
memset(pc, 0, sizeof(pc));
memset(pd, 0, sizeof(pd));
memset(&inp,0, sizeof(inp));
memset(&outp,0, sizeof(outp));
memset(&sif,0, sizeof(sif));
pfm_get_num_counters(&num_counters);
if (pfm_get_cycle_event(&inp.pfp_events[0]) != PFMLIB_SUCCESS)
fatal_error("cannot find cycle event\n");
if (pfm_get_inst_retired_event(&inp.pfp_events[1]) != PFMLIB_SUCCESS)
fatal_error("cannot find inst retired event\n");
i = 2;
/*
* set the privilege mode:
* PFM_PLM3 : user level
* PFM_PLM0 : kernel level
*/
inp.pfp_dfl_plm = PFM_PLM3;
if (i > num_counters) {
i = num_counters;
printf("too many events provided (max=%d events), using first %d event(s)\n", num_counters, i);
}
/*
* how many counters we use
*/
inp.pfp_event_count = i;
/*
* now create a session. we will later attach it to the task we are creating.
*/
ctx_fd = pfm_create(0, &sif);
if (ctx_fd == -1) {
if (errno == ENOSYS) {
fatal_error("Your kernel does not have performance monitoring support!\n");
}
fatal_error("cannot create session %s\n", strerror(errno));
}
/*
* build the pfp_unavail_pmcs bitmask by looking
* at what perfmon has available. It is not always
* the case that all PMU registers are actually available
* to applications. For instance, on IA-32 platforms, some
* registers may be reserved for the NMI watchdog timer.
*
* With this bitmap, the library knows which registers NOT to
* use. Of source, it is possible that no valid assignement may
* be possible if certina PMU registers are not available.
*/
detect_unavail_pmu_regs(&sif, &inp.pfp_unavail_pmcs, NULL);
/*
* let the library figure out the values for the PMCS
*/
if ((ret=pfm_dispatch_events(&inp, NULL, &outp, NULL)) != PFMLIB_SUCCESS) {
fatal_error("cannot configure events: %s\n", pfm_strerror(ret));
}
/*
* use our file descriptor for the poll.
* we are interested in read events only.
*/
pollfd.fd = ctx_fd;
pollfd.events = POLLIN;
/*
* Now prepare the argument to initialize the PMDs and PMCS.
* We must pfp_pmc_count to determine the number of PMC to intialize.
* We must use pfp_event_count to determine the number of PMD to initialize.
* Some events causes extra PMCs to be used, so pfp_pmc_count may be >= pfp_event_count.
*
* This step is new compared to libpfm-2.x. It is necessary because the library no
* longer knows about the kernel data structures.
*/
for (i=0; i < outp.pfp_pmc_count; i++) {
pc[i].reg_num = outp.pfp_pmcs[i].reg_num;
pc[i].reg_value = outp.pfp_pmcs[i].reg_value;
}
for (i=0; i < outp.pfp_pmd_count; i++)
pd[i].reg_num = outp.pfp_pmds[i].reg_num;
/*
* Now program the registers
*
* We don't use the save variable to indicate the number of elements passed to
* the kernel because, as we said earlier, pc may contain more elements than
* the number of events we specified, i.e., contains more thann counting monitors.
*/
if (pfm_write(ctx_fd, 0, PFM_RW_PMC, pc, outp.pfp_pmc_count * sizeof(*pc)) == -1)
fatal_error("pfm_write error errno %d\n",errno);
/*
* To be read, each PMD must be either written or declared
* as being part of a sample (reg_smpl_pmds)
*/
if (pfm_write(ctx_fd, 0, PFM_RW_PMD, pd, outp.pfp_pmd_count * sizeof(*pd)) == -1)
fatal_error("pfm_write(PMD) error errno %d\n",errno);
ret = ptrace(PTRACE_ATTACH, pid, NULL, 0);
if (ret == -1)
fatal_error("cannot attach to %d: %s\n", pid, strerror(errno));
/*
* wait for the child to be actually stopped
*/
waitpid(pid, &status, WUNTRACED);
/*
* check if process exited early
*/
if (WIFEXITED(status))
fatal_error("command process %d exited too early with status %d\n", pid, WEXITSTATUS(status));
/*
* the task is stopped at this point
*/
/*
* now we attach (i.e., attach) the session to ourself
*/
if (pfm_attach(ctx_fd, 0, pid) == -1)
fatal_error("pfm_attach error errno %d\n",errno);
/*
* activate monitoring. The task is still STOPPED at this point. Monitoring
* will not take effect until the execution of the task is resumed.
*/
if (pfm_set_state(ctx_fd, 0, PFM_ST_START) == -1)
fatal_error("pfm_set_state(start) error errno %d\n",errno);
/*
* now resume execution of the task, effectively activating
* monitoring.
*/
ptrace(PTRACE_DETACH, pid, NULL, 0);
printf("attached to [%d], timeout set to %lu seconds\n", pid, delay);
/*
* now the task is running
*/
/*
* We cannot simply do a waitpid() because we may be attaching to a process
* totally unrelated to our program. Instead we use a perfmon facility that
* notifies us when the monitoring task is exiting.
*
* When a task with a monitoring session attached to it exits, a PFM_MSG_END
* is generated. It can be retrieve with a simple read() on the session's descriptor.
*
* Another reason why you might return from the read is if there was a counter
* overflow, unlikely in this example.
*
* To measure only for short period of time, use select or poll with a timeout,
* see task_attach_timeout.c
*
*/
ret = poll(&pollfd, 1, delay*1000);
switch( ret ) {
case -1:
fatal_error("cannot read from descriptor: %s\n", strerror(errno));
/* no return */
case 1:
/*
* there is a message, i.e., the program exited before our timeout
*/
if (ret == 1) {
/*
* extract message
*/
ret = read(ctx_fd, &msg, sizeof(msg));
if (msg.type != PFM_MSG_END)
fatal_error("unexpected msg type : %d\n", msg.type);
}
break;
case 0:
/*
* we timed out, we need to stop the task to unload
*/
ret = ptrace(PTRACE_ATTACH, pid, NULL, 0);
if (ret == -1)
fatal_error("cannot attach to %d: %s\n", pid, strerror(errno));
/*
* wait for task to be actually stopped
*/
waitpid(pid, &status, WUNTRACED);
/*
* check if process exited, then no need to unload
*/
if (WIFEXITED(status)) goto read_results;
if (pfm_attach(ctx_fd, 0, PFM_NO_TARGET) == -1)
fatal_error("pfm_detach error errno %d\n",errno);
/*
* let it run free again
*/
ptrace(PTRACE_DETACH, pid, NULL, 0);
break;
default:
fatal_error("unexpected return from poll: %d\n", ret);
}
read_results:
/*
* now simply read the results.
*/
if (pfm_read(ctx_fd, 0, PFM_RW_PMD, pd, inp.pfp_event_count * sizeof(*pd)) == -1) {
fatal_error("pfm_read(PMD) error errno %d\n",errno);
return -1;
}
/*
* print the results
*
* It is important to realize, that the first event we specified may not
* be in PMD4. Not all events can be measured by any monitor. That's why
* we need to use the pc[] array to figure out where event i was allocated.
*
*/
for (i=0; i < inp.pfp_event_count; i++) {
pfm_get_full_event_name(&inp.pfp_events[i], name, MAX_EVT_NAME_LEN);
printf("PMD%-3u %20"PRIu64" %s\n",
pd[i].reg_num,
pd[i].reg_value,
name);
}
/*
* free the session
*/
close(ctx_fd);
return 0;
}
int
main(int argc, char **argv)
{
pfarg_ctx_t ctx;
pfarg_pmc_t pc[NUM_PMCS];
pfarg_pmd_t *pd;
pfmlib_input_param_t inp;
pfmlib_output_param_t outp;
uint64_t cpu_list;
void *desc;
unsigned int num_counters;
uint32_t i, j, k, l, ncpus, npmds;
size_t len;
int ret;
char *name;
if (pfm_initialize() != PFMLIB_SUCCESS)
fatal_error("cannot initialize libpfm\n");
if (pfms_initialize())
fatal_error("cannot initialize libpfms\n");
pfm_get_num_counters(&num_counters);
pfm_get_max_event_name_len(&len);
name = malloc(len+1);
if (name == NULL)
fatal_error("cannot allocate memory for event name\n");
memset(&ctx, 0, sizeof(ctx));
memset(pc, 0, sizeof(pc));
memset(&inp,0, sizeof(inp));
memset(&outp,0, sizeof(outp));
cpu_list = argc > 1 ? strtoul(argv[1], NULL, 0) : 0x3;
ncpus = popcount(cpu_list);
if (pfm_get_cycle_event(&inp.pfp_events[0].event) != PFMLIB_SUCCESS)
fatal_error("cannot find cycle event\n");
if (pfm_get_inst_retired_event(&inp.pfp_events[1].event) != PFMLIB_SUCCESS)
fatal_error("cannot find inst retired event\n");
i = 2;
inp.pfp_dfl_plm = PFM_PLM3|PFM_PLM0;
if (i > num_counters) {
i = num_counters;
printf("too many events provided (max=%d events), using first %d event(s)\n", num_counters, i);
}
/*
* how many counters we use
*/
inp.pfp_event_count = i;
/*
* indicate we are using the monitors for a system-wide session.
* This may impact the way the library sets up the PMC values.
*/
inp.pfp_flags = PFMLIB_PFP_SYSTEMWIDE;
/*
* let the library figure out the values for the PMCS
*/
if ((ret=pfm_dispatch_events(&inp, NULL, &outp, NULL)) != PFMLIB_SUCCESS)
fatal_error("cannot configure events: %s\n", pfm_strerror(ret));
npmds = ncpus * inp.pfp_event_count;
dprint("ncpus=%u npmds=%u\n", ncpus, npmds);
pd = calloc(npmds, sizeof(pfarg_pmd_t));
if (pd == NULL)
fatal_error("cannot allocate pd array\n");
for (i=0; i < outp.pfp_pmc_count; i++) {
pc[i].reg_num = outp.pfp_pmcs[i].reg_num;
pc[i].reg_value = outp.pfp_pmcs[i].reg_value;
}
for(l=0, k = 0; l < ncpus; l++) {
for (i=0, j=0; i < inp.pfp_event_count; i++, k++) {
pd[k].reg_num = outp.pfp_pmcs[j].reg_pmd_num;
for(; j < outp.pfp_pmc_count; j++) if (outp.pfp_pmcs[j].reg_evt_idx != i) break;
}
}
/*
* create a context on all CPUs we asked for
*
* libpfms only works for system-wide, so we set the flag in
* the master context. the context argument is not modified by
* call.
*
* desc is an opaque descriptor used to identify session.
*/
ctx.ctx_flags = PFM_FL_SYSTEM_WIDE;
ret = pfms_create(&cpu_list, 1, &ctx, NULL, &desc);
if (ret == -1)
fatal_error("create error %d\n", ret);
/*
* program the PMC registers on all CPUs of interest
*/
ret = pfms_write_pmcs(desc, pc, outp.pfp_pmc_count);
if (ret == -1)
fatal_error("write_pmcs error %d\n", ret);
/*
* program the PMD registers on all CPUs of interest
*/
ret = pfms_write_pmds(desc, pd, inp.pfp_event_count);
if (ret == -1)
fatal_error("write_pmds error %d\n", ret);
/*
* load context on all CPUs of interest
*/
ret = pfms_load(desc);
if (ret == -1)
fatal_error("load error %d\n", ret);
/*
* start monitoring on all CPUs of interest
*/
ret = pfms_start(desc);
if (ret == -1)
fatal_error("start error %d\n", ret);
/*
* simulate some work
*/
sleep(10);
/*
* stop monitoring on all CPUs of interest
*/
ret = pfms_stop(desc);
if (ret == -1)
fatal_error("stop error %d\n", ret);
/*
* read the PMD registers on all CPUs of interest.
* The pd[] array must be organized such that to
* read 2 PMDs on each CPU you need:
* - 2 * number of CPUs of interest
* - the first 2 elements of pd[] read on 1st CPU
* - the next 2 elements of pd[] read on the 2nd CPU
* - and so on
*/
ret = pfms_read_pmds(desc, pd, npmds);
if (ret == -1)
fatal_error("read_pmds error %d\n", ret);
/*
* pre per-CPU results
*/
for(j=0, k= 0; j < ncpus; j++) {
for (i=0; i < inp.pfp_event_count; i++, k++) {
pfm_get_full_event_name(&inp.pfp_events[i], name, len);
printf("CPU%-3d PMD%u %20"PRIu64" %s\n",
j,
pd[k].reg_num,
pd[k].reg_value,
name);
}
}
/*
* destroy context on all CPUs of interest.
* After this call desc is invalid
*/
ret = pfms_close(desc);
if (ret == -1)
fatal_error("close error %d\n", ret);
free(name);
return 0;
}
int
parent(pid_t pid, unsigned long delay)
{
pfmlib_input_param_t inp;
pfmlib_output_param_t outp;
pfarg_context_t ctx[1];
pfarg_reg_t pc[NUM_PMCS];
pfarg_reg_t pd[NUM_PMDS];
pfarg_load_t load_args;
struct pollfd pollfd;
pfm_msg_t msg;
unsigned int i, num_counters;
int status, ret;
int ctx_fd;
char name[MAX_EVT_NAME_LEN];
memset(pc, 0, sizeof(ctx));
memset(pd, 0, sizeof(ctx));
memset(ctx, 0, sizeof(ctx));
memset(&inp,0, sizeof(inp));
memset(&outp,0, sizeof(outp));
memset(&load_args,0, sizeof(load_args));
pfm_get_num_counters(&num_counters);
if (pfm_get_cycle_event(&inp.pfp_events[0]) != PFMLIB_SUCCESS)
fatal_error("cannot find cycle event\n");
if (pfm_get_inst_retired_event(&inp.pfp_events[1]) != PFMLIB_SUCCESS)
fatal_error("cannot find inst retired event\n");
i = 2;
if (num_counters < i) {
i = num_counters;
printf("too many events provided (max=%d events), using first %d event(s)\n", num_counters, i);
}
/*
* set the privilege mode:
* PFM_PLM3 : user level
* PFM_PLM0 : kernel level
*/
inp.pfp_dfl_plm = PFM_PLM3;
/*
* how many counters we use
*/
inp.pfp_event_count = i;
/*
* let the library figure out the values for the PMCS
*/
if ((ret=pfm_dispatch_events(&inp, NULL, &outp, NULL)) != PFMLIB_SUCCESS) {
fatal_error("cannot configure events: %s\n", pfm_strerror(ret));
}
/*
* now create a context. we will later attach it to the task we are creating.
*/
if (perfmonctl(0, PFM_CREATE_CONTEXT, ctx, 1) == -1) {
if (errno == ENOSYS) {
fatal_error("Your kernel does not have performance monitoring support!\n");
}
fatal_error("Can't create PFM context %s\n", strerror(errno));
}
/*
* extract the identifier for our context
*/
ctx_fd = ctx[0].ctx_fd;
/*
* use our file descriptor for the poll.
* we are interested in read events only.
*/
pollfd.fd = ctx_fd;
pollfd.events = POLLIN;
/*
* Now prepare the argument to initialize the PMDs and PMCS.
* We must pfp_pmc_count to determine the number of PMC to intialize.
* We must use pfp_event_count to determine the number of PMD to initialize.
* Some events causes extra PMCs to be used, so pfp_pmc_count may be >= pfp_event_count.
*
* This step is new compared to libpfm-2.x. It is necessary because the library no
* longer knows about the kernel data structures.
*/
for (i=0; i < outp.pfp_pmc_count; i++) {
pc[i].reg_num = outp.pfp_pmcs[i].reg_num;
pc[i].reg_value = outp.pfp_pmcs[i].reg_value;
}
/*
* the PMC controlling the event ALWAYS come first, that's why this loop
* is safe even when extra PMC are needed to support a particular event.
*/
for (i=0; i < inp.pfp_event_count; i++) {
pd[i].reg_num = pc[i].reg_num;
}
/*
* Now program the registers
*
* We don't use the save variable to indicate the number of elements passed to
* the kernel because, as we said earlier, pc may contain more elements than
* the number of events we specified, i.e., contains more thann counting monitors.
*/
if (perfmonctl(ctx_fd, PFM_WRITE_PMCS, pc, outp.pfp_pmc_count) == -1) {
fatal_error("perfmonctl error PFM_WRITE_PMCS errno %d\n",errno);
}
if (perfmonctl(ctx_fd, PFM_WRITE_PMDS, pd, inp.pfp_event_count) == -1) {
fatal_error("perfmonctl error PFM_WRITE_PMDS errno %d\n",errno);
}
ret = ptrace(PTRACE_ATTACH, pid, NULL, 0);
if (ret == -1) {
fatal_error("cannot attach to %d: %s\n", pid, strerror(errno));
}
/*
* wait for the child to be actually stopped
*/
waitpid(pid, &status, WUNTRACED);
/*
* check if process exited early
*/
if (WIFEXITED(status)) {
fatal_error("command process %d exited too early with status %d\n", pid, WEXITSTATUS(status));
}
/*
* the task is stopped at this point
*/
/*
* now we load (i.e., attach) the context to ourself
*/
load_args.load_pid = pid;
if (perfmonctl(ctx_fd, PFM_LOAD_CONTEXT, &load_args, 1) == -1) {
fatal_error("perfmonctl error PFM_LOAD_CONTEXT errno %d\n",errno);
}
/*
* activate monitoring. The task is still STOPPED at this point. Monitoring
* will not take effect until the execution of the task is resumed.
*/
if (perfmonctl(ctx_fd, PFM_START, NULL, 0) == -1) {
fatal_error("perfmonctl error PFM_START errno %d\n",errno);
}
/*
* now resume execution of the task, effectively activating
* monitoring.
*/
ptrace(PTRACE_DETACH, pid, NULL, 0);
printf("attached to [%d], timeout set to %lu seconds\n", pid, delay);
/*
* now the task is running
*/
/*
* We cannot simply do a waitpid() because we may be attaching to a process
* totally unrelated to our program. Instead we use a perfmon facility that
* notifies us when the monitoring task is exiting.
*
* When a task with a monitoring context attached to it exits, a PFM_MSG_END
* is generated. It can be retrieve with a simple read() on the context's descriptor.
*
* Another reason why you might return from the read is if there was a counter
* overflow, unlikely in this example.
*
* To measure only for short period of time, use select or poll with a timeout,
* see task_attach_timeout.c
*
*/
ret = poll(&pollfd, 1, delay*1000);
switch( ret ) {
case -1:
fatal_error("cannot read from descriptor: %s\n", strerror(errno));
/* no return */
case 1:
/*
* there is a message, i.e., the program exited before our timeout
*/
if (ret == 1) {
/*
* extract message
*/
ret = read(ctx_fd, &msg, sizeof(msg));
if (msg.type != PFM_MSG_END) {
fatal_error("unexpected msg type : %d\n", msg.type);
}
}
break;
case 0:
/*
* we timed out, we need to stop the task to unload
*/
ret = ptrace(PTRACE_ATTACH, pid, NULL, 0);
if (ret == -1) {
fatal_error("cannot attach to %d: %s\n", pid, strerror(errno));
}
/*
* wait for task to be actually stopped
*/
waitpid(pid, &status, WUNTRACED);
/*
* check if process exited, then no need to unload
*/
if (WIFEXITED(status)) goto read_results;
if (perfmonctl(ctx_fd, PFM_UNLOAD_CONTEXT, NULL, 0) == -1) {
fatal_error("perfmonctl error PFM_UNLOAD_CONTEXT errno %d\n",errno);
}
/*
* let it run free again
*/
ptrace(PTRACE_DETACH, pid, NULL, 0);
break;
default:
fatal_error("unexpected return from poll: %d\n", ret);
}
read_results:
/*
* now simply read the results.
*/
if (perfmonctl(ctx_fd, PFM_READ_PMDS, pd, inp.pfp_event_count) == -1) {
fatal_error("perfmonctl error READ_PMDS errno %d\n",errno);
return -1;
}
/*
* print the results
*
* It is important to realize, that the first event we specified may not
* be in PMD4. Not all events can be measured by any monitor. That's why
* we need to use the pc[] array to figure out where event i was allocated.
*
*/
for (i=0; i < inp.pfp_event_count; i++) {
pfm_get_full_event_name(&inp.pfp_events[i], name, MAX_EVT_NAME_LEN);
printf("PMD%u %20"PRIu64" %s\n",
pd[i].reg_num,
pd[i].reg_value,
name);
}
/*
* free the context
*/
close(ctx_fd);
return 0;
}
int
main(int argc, char **argv)
{
pfarg_context_t ctx[1];
pfmlib_input_param_t inp;
pfmlib_output_param_t outp;
pfarg_reg_t pc[NUM_PMCS];
pfarg_load_t load_args;
pfmlib_options_t pfmlib_options;
struct sigaction act;
size_t len;
unsigned int i, num_counters;
int ret;
/*
* Initialize pfm library (required before we can use it)
*/
if (pfm_initialize() != PFMLIB_SUCCESS) {
printf("Can't initialize library\n");
exit(1);
}
/*
* Install the signal handler (SIGIO)
*/
memset(&act, 0, sizeof(act));
act.sa_handler = (sig_t)sigio_handler;
sigaction (SIGIO, &act, 0);
/*
* pass options to library (optional)
*/
memset(&pfmlib_options, 0, sizeof(pfmlib_options));
pfmlib_options.pfm_debug = 0; /* set to 1 for debug */
pfm_set_options(&pfmlib_options);
memset(pc, 0, sizeof(pc));
memset(ctx, 0, sizeof(ctx));
memset(&load_args, 0, sizeof(load_args));
memset(&inp,0, sizeof(inp));
memset(&outp,0, sizeof(outp));
pfm_get_num_counters(&num_counters);
if (pfm_get_cycle_event(&inp.pfp_events[0]) != PFMLIB_SUCCESS)
fatal_error("cannot find cycle event\n");
if (pfm_get_inst_retired_event(&inp.pfp_events[1]) != PFMLIB_SUCCESS)
fatal_error("cannot find inst retired event\n");
i = 2;
if (i > num_counters) {
i = num_counters;
printf("too many events provided (max=%d events), using first %d event(s)\n", num_counters, i);
}
/*
* set the default privilege mode for all counters:
* PFM_PLM3 : user level only
*/
inp.pfp_dfl_plm = PFM_PLM3;
/*
* how many counters we use
*/
inp.pfp_event_count = i;
/*
* how many counters we use
*/
if (i > 1) {
inp.pfp_event_count = i;
pfm_get_max_event_name_len(&len);
event1_name = malloc(len+1);
if (event1_name == NULL)
fatal_error("cannot allocate event name\n");
pfm_get_full_event_name(&inp.pfp_events[1], event1_name, len+1);
}
/*
* let the library figure out the values for the PMCS
*/
if ((ret=pfm_dispatch_events(&inp, NULL, &outp, NULL)) != PFMLIB_SUCCESS) {
fatal_error("Cannot configure events: %s\n", pfm_strerror(ret));
}
/*
* when we know we are self-monitoring and we have only one context, then
* when we get an overflow we know where it is coming from. Therefore we can
* save the call to the kernel to extract the notification message. By default,
* a message is generated. The queue of messages has a limited size, therefore
* it is important to clear the queue by reading the message on overflow. Failure
* to do so may result in a queue full and you will lose notification messages.
*
* With the PFM_FL_OVFL_NO_MSG, no message will be queue, but you will still get
* the signal. Similarly, the PFM_MSG_END will be generated.
*/
ctx[0].ctx_flags = PFM_FL_OVFL_NO_MSG;
/*
* now create the context for self monitoring/per-task
*/
if (perfmonctl(0, PFM_CREATE_CONTEXT, ctx, 1) == -1 ) {
if (errno == ENOSYS) {
fatal_error("Your kernel does not have performance monitoring support!\n");
}
fatal_error("Can't create PFM context %s\n", strerror(errno));
}
ctx_fd = ctx->ctx_fd;
/*
* Now prepare the argument to initialize the PMDs and PMCS.
* We use pfp_pmc_count to determine the number of registers to
* setup. Note that this field can be >= pfp_event_count.
*/
for (i=0; i < outp.pfp_pmc_count; i++) {
pc[i].reg_num = outp.pfp_pmcs[i].reg_num;
pc[i].reg_value = outp.pfp_pmcs[i].reg_value;
}
for (i=0; i < inp.pfp_event_count; i++) {
pd[i].reg_num = pc[i].reg_num;
}
/*
* We want to get notified when the counter used for our first
* event overflows
*/
pc[0].reg_flags |= PFM_REGFL_OVFL_NOTIFY;
pc[0].reg_reset_pmds[0] |= 1UL << outp.pfp_pmcs[1].reg_num;
/*
* we arm the first counter, such that it will overflow
* after SMPL_PERIOD events have been observed
*/
pd[0].reg_value = (~0UL) - SMPL_PERIOD + 1;
pd[0].reg_long_reset = (~0UL) - SMPL_PERIOD + 1;
pd[0].reg_short_reset = (~0UL) - SMPL_PERIOD + 1;
/*
* Now program the registers
*
* We don't use the save variable to indicate the number of elements passed to
* the kernel because, as we said earlier, pc may contain more elements than
* the number of events we specified, i.e., contains more than counting monitors.
*/
if (perfmonctl(ctx_fd, PFM_WRITE_PMCS, pc, outp.pfp_pmc_count) == -1) {
fatal_error("perfmonctl error PFM_WRITE_PMCS errno %d\n",errno);
}
if (perfmonctl(ctx_fd, PFM_WRITE_PMDS, pd, inp.pfp_event_count) == -1) {
fatal_error("perfmonctl error PFM_WRITE_PMDS errno %d\n",errno);
}
/*
* we want to monitor ourself
*/
load_args.load_pid = getpid();
if (perfmonctl(ctx_fd, PFM_LOAD_CONTEXT, &load_args, 1) == -1) {
fatal_error("perfmonctl error PFM_WRITE_PMDS errno %d\n",errno);
}
/*
* setup asynchronous notification on the file descriptor
*/
ret = fcntl(ctx_fd, F_SETFL, fcntl(ctx_fd, F_GETFL, 0) | O_ASYNC);
if (ret == -1) {
fatal_error("cannot set ASYNC: %s\n", strerror(errno));
}
/*
* get ownership of the descriptor
*/
ret = fcntl(ctx_fd, F_SETOWN, getpid());
if (ret == -1) {
fatal_error("cannot setown: %s\n", strerror(errno));
}
/*
* Let's roll now
*/
pfm_self_start(ctx_fd);
busyloop();
pfm_self_stop(ctx_fd);
/*
* free our context
*/
close(ctx_fd);
return 0;
}
