/** program the perfmon counters */
static void write_pmu(struct child * self)
{
pfarg_reg_t pc[OP_MAX_COUNTERS];
pfarg_reg_t pd[OP_MAX_COUNTERS];
int err;
size_t i;
memset(pc, 0, sizeof(pc));
memset(pd, 0, sizeof(pd));
#define PMC_GEN_INTERRUPT (1UL << 5)
#define PMC_PRIV_MONITOR (1UL << 6)
/* McKinley requires pmc4 to have bit 23 set (enable PMU).
* It is supposedly ignored in other pmc registers.
*/
#define PMC_MANDATORY (1UL << 23)
#define PMC_USER (1UL << 3)
#define PMC_KERNEL (1UL << 0)
for (i = 0; i < op_nr_counters && opd_events[i].name; ++i) {
struct opd_event * event = &opd_events[i];
pc[i].reg_num = event->counter + 4;
pc[i].reg_value = PMC_GEN_INTERRUPT;
pc[i].reg_value |= PMC_PRIV_MONITOR;
pc[i].reg_value |= PMC_MANDATORY;
(event->user) ? (pc[i].reg_value |= PMC_USER)
: (pc[i].reg_value &= ~PMC_USER);
(event->kernel) ? (pc[i].reg_value |= PMC_KERNEL)
: (pc[i].reg_value &= ~PMC_KERNEL);
pc[i].reg_value &= ~(0xff << 8);
pc[i].reg_value |= ((event->value & 0xff) << 8);
pc[i].reg_value &= ~(0xf << 16);
pc[i].reg_value |= ((event->um & 0xf) << 16);
pc[i].reg_smpl_eventid = event->counter;
}
for (i = 0; i < op_nr_counters && opd_events[i].name; ++i) {
struct opd_event * event = &opd_events[i];
pd[i].reg_value = ~0UL - event->count + 1;
pd[i].reg_short_reset = ~0UL - event->count + 1;
pd[i].reg_num = event->counter + 4;
}
err = perfmonctl(self->ctx_fd, PFM_WRITE_PMCS, pc, i);
if (err == -1) {
perror("Couldn't write PMCs");
exit(EXIT_FAILURE);
}
err = perfmonctl(self->ctx_fd, PFM_WRITE_PMDS, pd, i);
if (err == -1) {
perror("Couldn't write PMDs");
exit(EXIT_FAILURE);
}
}
static void perfmon_start_child(int ctx_fd)
{
if (perfmonctl(ctx_fd, PFM_START, 0, 0) == -1) {
perror("Couldn't start perfmon: ");
exit(EXIT_FAILURE);
}
}
static void
overflow_handler(int n, struct pfm_siginfo *info, struct sigcontext *sc)
{
unsigned long mask =info->sy_pfm_ovfl[0];
pfarg_reg_t pd[1];
/*
* Check to see if we received a spurious SIGPROF, i.e., one not
* generated by the perfmon subsystem.
*/
if (info->sy_code != PROF_OVFL) {
printf("Received spurious SIGPROF si_code=%d\n", info->sy_code);
return;
}
/*
* Each bit set in the overflow mask represents an overflowed counter.
*
* Here we check that the overflow was caused by our first counter.
*/
if ((mask & (1UL<< evt.pfp_pc[0].reg_num)) == 0) {
printf("Something is wrong, unexpected mask 0x%lx\n", mask);
exit(1);
}
/*
* Read the value of the second counter
*/
pd[0].reg_num = evt.pfp_pc[1].reg_num;
if (perfmonctl(getpid(), PFM_READ_PMDS, pd, 1) == -1) {
perror("PFM_READ_PMDS");
exit(1);
}
printf("Notification received\n");
process_smpl_buffer();
/*
* And resume monitoring
*/
if (perfmonctl(getpid(), PFM_RESTART,NULL, 0) == -1) {
perror("PFM_RESTART");
exit(1);
}
/* Here we have the PMU enabled and are capturing events */
}
static void load_context(struct child * self)
{
pfarg_load_t load_args;
int err;
memset(&load_args, 0, sizeof(load_args));
load_args.load_pid = self->pid;
err = perfmonctl(self->ctx_fd, PFM_LOAD_CONTEXT, &load_args, 1);
if (err == -1) {
perror("Couldn't load context");
exit(EXIT_FAILURE);
}
}
static void
sigio_handler(int n, struct siginfo *info, struct sigcontext *sc)
{
if (perfmonctl(ctx_fd, PFM_READ_PMDS, pd+1, 1) == -1) {
fatal_error("PFM_READ_PMDS: %s", strerror(errno));
}
/*
* we do not need to extract the overflow message, we know
* where it is coming from.
*/
/*
* XXX: risky to do printf() in signal handler!
*/
if (event1_name)
printf("Notification %02lu: %"PRIu64" %s\n", notification_received, pd[1].reg_value, event1_name);
else
printf("Notification %02lu:\n", notification_received);
/*
* At this point, the counter used for the sampling period has already
* be reset by the kernel because we are in non-blocking mode, self-monitoring.
*/
/*
* increment our notification counter
*/
notification_received++;
/*
* And resume monitoring
*/
if (perfmonctl(ctx_fd, PFM_RESTART,NULL, 0) == -1) {
fatal_error("PFM_RESTART: %s", strerror(errno));
}
}
/** create the per-cpu context */
static void create_context(struct child * self)
{
pfarg_context_t ctx;
int err;
memset(&ctx, 0, sizeof(pfarg_context_t));
memcpy(&ctx.ctx_smpl_buf_id, &uuid, 16);
ctx.ctx_flags = PFM_FL_SYSTEM_WIDE;
err = perfmonctl(0, PFM_CREATE_CONTEXT, &ctx, 1);
if (err == -1) {
perror("CREATE_CONTEXT failed");
exit(EXIT_FAILURE);
}
self->ctx_fd = ctx.ctx_fd;
}
int
main(int argc, char **argv)
{
unsigned int i, cnum = 0;
pfarg_reg_t pc[NUM_PMCS];
pfmlib_regmask_t impl_pmcs;
unsigned int num_pmcs;
/*
* Initialize pfm library (required before we can use it)
*/
if (pfm_initialize() != PFMLIB_SUCCESS) {
printf("Can't initialize library\n");
exit(1);
}
memset(&impl_pmcs, 0, sizeof(impl_pmcs));
memset(pc, 0, sizeof(pc));
pfm_get_impl_pmcs(&impl_pmcs);
pfm_get_num_pmcs(&num_pmcs);
for(i=0; num_pmcs ; i++) {
if (pfm_regmask_isset(&impl_pmcs, i) == 0) continue;
pc[cnum++].reg_num = i;
num_pmcs--;
}
if (perfmonctl(0, PFM_GET_PMC_RESET_VAL, pc, cnum) == -1 ) {
if (errno == ENOSYS) {
fatal_error("Your kernel does not have performance monitoring support!\n");
}
fatal_error("cannot get reset values: %s\n", strerror(errno));
}
for (i=0; i < cnum; i++) {
printf("PMC%u 0x%lx\n", pc[i].reg_num, pc[i].reg_value);
}
return 0;
}
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
main(void)
{
int ret;
int type = 0;
pid_t pid = getpid();
pfmlib_ita2_param_t ita_param;
pfarg_reg_t pd[NUM_PMDS];
pfarg_context_t ctx[1];
pfmlib_options_t pfmlib_options;
struct sigaction act;
/*
* Initialize pfm library (required before we can use it)
*/
if (pfm_initialize() != PFMLIB_SUCCESS) {
fatal_error("Can't initialize library\n");
}
/*
* Let's make sure we run this on the right CPU
*/
pfm_get_pmu_type(&type);
if (type != PFMLIB_ITANIUM2_PMU) {
char *model;
pfm_get_pmu_name(&model);
fatal_error("this program does not work with %s PMU\n", model);
}
/*
* Install the overflow handler (SIGPROF)
*/
memset(&act, 0, sizeof(act));
act.sa_handler = (sig_t)overflow_handler;
sigaction (SIGPROF, &act, 0);
/*
* pass options to library (optional)
*/
memset(&pfmlib_options, 0, sizeof(pfmlib_options));
pfmlib_options.pfm_debug = 0; /* set to 1 for debug */
pfmlib_options.pfm_verbose = 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));
memset(&ita_param,0, sizeof(ita_param));
/*
* because we use a model specific feature, we must initialize the
* model specific pfmlib parameter structure and link it to the
* common structure.
* The magic number is a simple mechanism used by the library to check
* that the model specific data structure is decent. You must set it manually
* otherwise the model specific feature won't work.
*/
ita_param.pfp_magic = PFMLIB_ITA2_PARAM_MAGIC;
evt.pfp_model = &ita_param;
/*
* Before calling pfm_find_dispatch(), we must specify what kind
* of branches we want to capture. We are interesteed in all the mispredicted branches,
* therefore we program we set the various fields of the BTB config to:
*/
ita_param.pfp_ita2_btb.btb_used = 1;
ita_param.pfp_ita2_btb.btb_ds = 0;
ita_param.pfp_ita2_btb.btb_tm = 0x3;
ita_param.pfp_ita2_btb.btb_ptm = 0x3;
ita_param.pfp_ita2_btb.btb_ppm = 0x3;
ita_param.pfp_ita2_btb.btb_brt = 0x0;
ita_param.pfp_ita2_btb.btb_plm = PFM_PLM3;
/*
* To count the number of occurence of this instruction, we must
* program a counting monitor with the IA64_TAGGED_INST_RETIRED_PMC8
* event.
*/
if (pfm_find_event_byname("BRANCH_EVENT", &evt.pfp_events[0].event) != PFMLIB_SUCCESS) {
fatal_error("cannot find event BRANCH_EVENT\n");
}
/*
* set the (global) privilege mode:
* PFM_PLM3 : user level only
*/
evt.pfp_dfl_plm = PFM_PLM3;
/*
* how many counters we use
*/
evt.pfp_event_count = 1;
/*
* 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 will get notified ONLY when the sampling
* buffer is full. The monitoring is not to be inherited
* in derived tasks
*/
ctx[0].ctx_flags = PFM_FL_INHERIT_NONE;
ctx[0].ctx_notify_pid = getpid();
ctx[0].ctx_smpl_entries = SMPL_BUF_NENTRIES;
ctx[0].ctx_smpl_regs[0] = smpl_regs = BTB_REGS_MASK;
/*
* 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));
}
printf("Sampling buffer mapped at %p\n", ctx[0].ctx_smpl_vaddr);
smpl_vaddr = ctx[0].ctx_smpl_vaddr;
/*
* 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);
}
/*
* indicate we want notification when buffer is full
*/
evt.pfp_pc[0].reg_flags |= PFM_REGFL_OVFL_NOTIFY;
/*
* Now prepare the argument to initialize the PMD and the sampling period
*/
pd[0].reg_num = evt.pfp_pc[0].reg_num;
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;
/*
* When our counter overflows, we want to BTB index to be reset, so that we keep
* in sync. This is required to make it possible to interpret pmd16 on overflow
* to avoid repeating the same branch several times.
*/
evt.pfp_pc[0].reg_reset_pmds[0] = M_PMD(16);
/*
* reset pmd16, short and long reset value are set to zero as well
*/
pd[1].reg_num = 16;
pd[1].reg_value = 0UL;
/*
* 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, 2) == -1) {
fatal_error("perfmonctl error PFM_WRITE_PMDS errno %d\n",errno);
}
/*
* Let's roll now.
*/
do_test(100000);
/*
* We must call the processing routine to cover the last entries recorded
* in the sampling buffer, i.e. which may not be full
*/
process_smpl_buffer();
/*
* let's stop this now
*/
if (perfmonctl(pid, PFM_DESTROY_CONTEXT, NULL, 0) == -1) {
fatal_error("perfmonctl error PFM_DESTROY errno %d\n",errno);
}
return 0;
}
static void perfmon_start_child(int ctx_fd)
{
if (perfmonctl(ctx_fd, PFM_START, 0, 0) == -1) {
exit(EXIT_FAILURE);
}
}
int
main(void)
{
pfmlib_input_param_t inp;
pfmlib_output_param_t outp;
pfmlib_ita2_input_param_t ita2_inp;
pfarg_reg_t pd[NUM_PMDS];
pfarg_reg_t pc[NUM_PMCS];
pfarg_context_t ctx[1];
pfarg_load_t load_args;
pfmlib_options_t pfmlib_options;
int ret;
int type = 0;
int id;
unsigned int i;
char name[MAX_EVT_NAME_LEN];
/*
* Initialize pfm library (required before we can use it)
*/
if (pfm_initialize() != PFMLIB_SUCCESS) {
fatal_error("Can't initialize library\n");
}
/*
* Let's make sure we run this on the right CPU
*/
pfm_get_pmu_type(&type);
if (type != PFMLIB_ITANIUM2_PMU) {
char model[MAX_PMU_NAME_LEN];
pfm_get_pmu_name(model, MAX_PMU_NAME_LEN);
fatal_error("this program does not work with the %s PMU\n", model);
}
/*
* pass options to library (optional)
*/
memset(&pfmlib_options, 0, sizeof(pfmlib_options));
pfmlib_options.pfm_debug = 0; /* set to 1 for debug */
pfmlib_options.pfm_verbose = 0; /* set to 1 for verbose */
pfm_set_options(&pfmlib_options);
memset(pd, 0, sizeof(pd));
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));
memset(&ita2_inp,0, sizeof(ita2_inp));
/*
* We indicate that we are using the PMC8 opcode matcher. This is required
* otherwise the library add PMC8 to the list of PMC to pogram during
* pfm_dispatch_events().
*/
ita2_inp.pfp_ita2_pmc8.opcm_used = 1;
/*
* We want to match all the br.cloop in our test function.
* This branch is an IP-relative branch for which the major
* opcode (bits [40-37]=4) and the btype field is 5 (which represents
* bits[6-8]) so it is included in the match/mask fields of PMC8.
* It is necessarily in a B slot.
*
* We don't care which operands are used with br.cloop therefore
* the mask field of pmc8 is set such that only the 4 bits of the
* opcode and 3 bits of btype must match exactly. This is accomplished by
* clearing the top 4 bits and bits [6-8] of the mask field and setting the
* remaining bits. Similarly, the match field only has the opcode value and btype
* set according to the encoding of br.cloop, the
* remaining bits are zero. Bit 60 of PMC8 is set to indicate
* that we look only in B slots (this is the only possibility for
* this instruction anyway).
*
* So the binary representation of the value for PMC8 is as follows:
*
* 6666555555555544444444443333333333222222222211111111110000000000
* 3210987654321098765432109876543210987654321098765432109876543210
* ----------------------------------------------------------------
* 0001010000000000000000101000000000000011111111111111000111111000
*
* which yields a value of 0x1400028003fff1f8.
*
* Depending on the level of optimization to compile this code, it may
* be that the count reported could be zero, if the compiler uses a br.cond
* instead of br.cloop.
*
*
* The 0x1 sets the ig_ad field to make sure we ignore any range restriction.
* Also bit 2 must always be set
*/
ita2_inp.pfp_ita2_pmc8.pmc_val = 0x1400028003fff1fa;
/*
* To count the number of occurence of this instruction, we must
* program a counting monitor with the IA64_TAGGED_INST_RETIRED_PMC8
* event.
*/
if (pfm_find_full_event("IA64_TAGGED_INST_RETIRED_IBRP0_PMC8", &inp.pfp_events[0]) != PFMLIB_SUCCESS) {
fatal_error("cannot find event IA64_TAGGED_INST_RETIRED_IBRP0_PMC8\n");
}
/*
* set the privilege mode:
* PFM_PLM3 : user level only
*/
inp.pfp_dfl_plm = PFM_PLM3;
/*
* how many counters we use
*/
inp.pfp_event_count = 1;
/*
* let the library figure out the values for the PMCS
*/
if ((ret=pfm_dispatch_events(&inp, &ita2_inp, &outp, NULL)) != PFMLIB_SUCCESS) {
fatal_error("cannot configure events: %s\n", pfm_strerror(ret));
}
/*
* 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));
}
/*
* extract the unique identifier for our context, a regular file descriptor
*/
id = 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;
}
printf("event_count=%d id=%d\n", inp.pfp_event_count, id);
/*
* 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(id, PFM_WRITE_PMCS, pc, outp.pfp_pmc_count) == -1) {
fatal_error("perfmonctl error PFM_WRITE_PMCS errno %d\n",errno);
}
if (perfmonctl(id, PFM_WRITE_PMDS, pd, inp.pfp_event_count) == -1) {
fatal_error("perfmonctl error PFM_WRITE_PMDS errno %d\n",errno);
}
/*
* now we load (i.e., attach) the context to ourself
*/
load_args.load_pid = getpid();
if (perfmonctl(id, PFM_LOAD_CONTEXT, &load_args, 1) == -1) {
fatal_error("perfmonctl error PFM_LOAD_CONTEXT errno %d\n",errno);
}
/*
* Let's roll now.
*/
pfm_self_start(id);
do_test(100UL);
pfm_self_stop(id);
/*
* now read the results
*/
if (perfmonctl(id, PFM_READ_PMDS, pd, inp.pfp_event_count) == -1) {
fatal_error("perfmonctl error READ_PMDS errno %d\n",errno);
}
/*
* print the results
*/
pfm_get_full_event_name(&inp.pfp_events[0], name, MAX_EVT_NAME_LEN);
printf("PMD%u %20lu %s\n",
pd[0].reg_num,
pd[0].reg_value,
name);
if (pd[0].reg_value != 0)
printf("compiler used br.cloop\n");
else
printf("compiler did not use br.cloop\n");
/*
* let's stop this now
*/
close(id);
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(void)
{
int ret;
int type = 0;
char *name;
pid_t pid = getpid();
pfmlib_param_t evt;
pfmlib_ita2_param_t ita2_param;
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) {
fatal_error("Can't initialize library\n");
}
/*
* Let's make sure we run this on the right CPU
*/
pfm_get_pmu_type(&type);
if (type != PFMLIB_ITANIUM2_PMU) {
char *model;
pfm_get_pmu_name(&model);
fatal_error("this program does not work with the %s PMU\n", model);
}
/*
* pass options to library (optional)
*/
memset(&pfmlib_options, 0, sizeof(pfmlib_options));
pfmlib_options.pfm_debug = 0; /* set to 1 for debug */
pfmlib_options.pfm_verbose = 0; /* set to 1 for verbose */
pfm_set_options(&pfmlib_options);
memset(pd, 0, sizeof(pd));
memset(ctx, 0, sizeof(ctx));
memset(&evt,0, sizeof(evt));
memset(&ita2_param,0, sizeof(ita2_param));
/*
* because we use a model specific feature, we must initialize the
* model specific pfmlib parameter structure and link it to the
* common structure.
* The magic number is a simple mechanism used by the library to check
* that the model specific data structure is decent. You must set it manually
* otherwise the model specific feature won't work.
*/
ita2_param.pfp_magic = PFMLIB_ITA2_PARAM_MAGIC;
evt.pfp_model = &ita2_param;
/*
* We indicate that we are using the PMC8 opcode matcher. This is required
* otherwise the library add PMC8 to the list of PMC to pogram during
* pfm_dispatch_events().
*/
ita2_param.pfp_ita2_pmc8.opcm_used = 1;
/*
* We want to match all the br.cloop in our test function.
* This branch is an IP-relative branch for which the major
* opcode (bits [40-37]=4) and the btype field is 5 (which represents
* bits[6-8]) so it is included in the match/mask fields of PMC8.
* It is necessarily in a B slot.
*
* We don't care which operands are used with br.cloop therefore
* the mask field of pmc8 is set such that only the 4 bits of the
* opcode and 3 bits of btype must match exactly. This is accomplished by
* clearing the top 4 bits and bits [6-8] of the mask field and setting the
* remaining bits. Similarly, the match field only has the opcode value and btype
* set according to the encoding of br.cloop, the
* remaining bits are zero. Bit 60 of PMC8 is set to indicate
* that we look only in B slots (this is the only possibility for
* this instruction anyway).
*
* So the binary representation of the value for PMC8 is as follows:
*
* 6666555555555544444444443333333333222222222211111111110000000000
* 3210987654321098765432109876543210987654321098765432109876543210
* ----------------------------------------------------------------
* 0001010000000000000000101000000000000011111111111111000111111000
*
* which yields a value of 0x1400028003fff1f8.
*
* Depending on the level of optimization to compile this code, it may
* be that the count reported could be zero, if the compiler uses a br.cond
* instead of br.cloop.
*
*
* The 0x1 sets the ig_ad field to make sure we ignore any range restriction.
* Also bit 2 must always be set
*/
ita2_param.pfp_ita2_pmc8.pmc_val = 0x1400028003fff1fa;
/*
* To count the number of occurence of this instruction, we must
* program a counting monitor with the IA64_TAGGED_INST_RETIRED_PMC8
* event.
*/
if (pfm_find_event_byname("IA64_TAGGED_INST_RETIRED_IBRP0_PMC8", &evt.pfp_events[0].event) != PFMLIB_SUCCESS) {
fatal_error("cannot find event IA64_TAGGED_INST_RETIRED_IBRP0_PMC8\n");
}
/*
* set the privilege mode:
* PFM_PLM3 : user level only
*/
evt.pfp_dfl_plm = PFM_PLM3;
/*
* how many counters we use
*/
evt.pfp_event_count = 1;
/*
* 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 PMD.
*/
pd[0].reg_num = evt.pfp_pc[0].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) {
fatal_error("perfmonctl error PFM_WRITE_PMDS errno %d\n",errno);
}
/*
* Let's roll now.
*/
pfm_start();
do_test(100UL);
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);
}
/*
* print the results
*/
pfm_get_event_name(evt.pfp_events[0].event, &name);
printf("PMD%u %20lu %s\n",
pd[0].reg_num,
pd[0].reg_value,
name);
if (pd[0].reg_value != 0)
printf("compiler used br.cloop\n");
else
printf("compiler did not use br.cloop\n");
/*
* let's stop this now
*/
if (perfmonctl(pid, PFM_DESTROY_CONTEXT, NULL, 0) == -1) {
fatal_error("perfmonctl error PFM_DESTROY errno %d\n",errno);
}
return 0;
}
static void
process_smpl_buf(int id, unsigned long smpl_pmd_mask, int need_restart)
{
static unsigned long last_overflow = ~0UL; /* initialize to biggest value possible */
smpl_hdr_t *hdr = (smpl_hdr_t *)buf_addr;
smpl_entry_t *ent;
unsigned long count, entry, *reg, pos, msk;
unsigned long entry_size;
int j;
printf("processing %s buffer at %p\n", need_restart==0 ? "leftover" : "", hdr);
if (hdr->hdr_overflows <= last_overflow && last_overflow != ~0UL) {
warning("skipping identical set of samples %lu <= %lu\n",
hdr->hdr_overflows, last_overflow);
return;
}
last_overflow = hdr->hdr_overflows;
count = hdr->hdr_count;
ent = (smpl_entry_t *)(hdr+1);
pos = (unsigned long)ent;
entry = collect_samples;
/*
* in this example program, we use fixed-size entries, therefore we
* can compute the entry size in advance. Perfmon-2 supports variable
* size entries.
*/
entry_size = sizeof(smpl_entry_t)+(bit_weight(smpl_pmd_mask)<<3);
while(count--) {
printf("entry %ld PID:%d CPU:%d IIP:0x%016lx\n",
entry,
ent->pid,
ent->cpu,
ent->ip);
printf("\tOVFL: %d LAST_VAL: %lu\n", ent->ovfl_pmd, -ent->last_reset_val);
/*
* print body: additional PMDs recorded
* PMD are recorded in increasing index order
*/
reg = (unsigned long *)(ent+1);
for(j=0, msk = smpl_pmd_mask; msk; msk >>=1, j++) {
if ((msk & 0x1) == 0) continue;
printf("PMD%-2d = 0x%016lx\n", j, *reg);
reg++;
}
/*
* we could have removed this and used:
* ent = (smpl_entry_t *)reg
* instead.
*/
pos += entry_size;
ent = (smpl_entry_t *)pos;
entry++;
}
collect_samples = entry;
/*
* reactivate monitoring once we are done with the samples
*
* Note that this call can fail with EBUSY in non-blocking mode
* as the task may have disappeared while we were processing
* the samples.
*/
if (need_restart && perfmonctl(id, PFM_RESTART, 0, 0) == -1) {
if (errno != EBUSY)
fatal_error("perfmonctl error PFM_RESTART errno %d\n",errno);
else
warning("PFM_RESTART: task has probably terminated \n");
}
}
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
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;
}
