/*
* task_smpl.c - example of a task sampling another one using a randomized sampling period
*
* Copyright (c) 2003-2006 Hewlett-Packard Development Company, L.P.
* Contributed by Stephane Eranian <eranian@hpl.hp.com>
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
* of the Software, and to permit persons to whom the Software is furnished to do so,
* subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all
* copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
* INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
* PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
* HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF
* CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE
* OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
#include <sys/types.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#include <errno.h>
#include <unistd.h>
#include <string.h>
#include <signal.h>
#include <stdarg.h>
#include <stdint.h>
#include <getopt.h>
#include <time.h>
#include <sys/ptrace.h>
#include <sys/wait.h>
#include <sys/mman.h>
#include <sys/time.h>
#include <sys/resource.h>
#include <perfmon/pfmlib.h>
#include <perfmon/perfmon.h>
#include <perfmon/perfmon_dfl_smpl.h>
#include "detect_pmcs.h"
#define SAMPLING_PERIOD 100000
typedef struct {
int opt_no_show;
int opt_block;
} options_t;
typedef pfm_dfl_smpl_arg_t smpl_fmt_arg_t;
typedef pfm_dfl_smpl_hdr_t smpl_hdr_t;
typedef pfm_dfl_smpl_entry_t smpl_entry_t;
typedef pfm_dfl_smpl_arg_t smpl_arg_t;
#define FMT_NAME PFM_DFL_SMPL_NAME
#define NUM_PMCS PFMLIB_MAX_PMCS
#define NUM_PMDS PFMLIB_MAX_PMDS
static uint64_t collected_samples, collected_partial;
static options_t options;
static struct option the_options[]={
{ "help", 0, 0, 1},
{ "ovfl-block", 0, &options.opt_block, 1},
{ "no-show", 0, &options.opt_no_show, 1},
{ 0, 0, 0, 0}
};
static void fatal_error(char *fmt,...) __attribute__((noreturn));
#define BPL (sizeof(uint64_t)<<3)
#define LBPL 6
static inline void pfm_bv_set(uint64_t *bv, uint16_t rnum)
{
bv[rnum>>LBPL] |= 1UL << (rnum&(BPL-1));
}
static inline int pfm_bv_isset(uint64_t *bv, uint16_t rnum)
{
return bv[rnum>>LBPL] & (1UL <<(rnum&(BPL-1))) ? 1 : 0;
}
static inline void pfm_bv_copy(uint64_t *d, uint64_t *j, uint16_t n)
{
if (n <= BPL)
*d = *j;
else {
memcpy(d, j, (n>>LBPL)*sizeof(uint64_t));
}
}
static void
warning(char *fmt, ...)
{
va_list ap;
va_start(ap, fmt);
vfprintf(stderr, fmt, ap);
va_end(ap);
}
static void
fatal_error(char *fmt, ...)
{
va_list ap;
va_start(ap, fmt);
vfprintf(stderr, fmt, ap);
va_end(ap);
exit(1);
}
int
child(char **arg)
{
/*
* force the task to stop before executing the first
* user level instruction
*/
ptrace(PTRACE_TRACEME, 0, NULL, NULL);
execvp(arg[0], arg);
/* not reached */
exit(1);
}
void
show_task_rusage(const struct timeval *start, const struct timeval *end, const struct rusage *ru)
{
long secs, suseconds, end_usec;
secs = end->tv_sec - start->tv_sec;
end_usec = end->tv_usec;
if (end_usec < start->tv_usec) {
end_usec += 1000000;
secs--;
}
suseconds = end_usec - start->tv_usec;
printf ("real %ldh%02ldm%02ld.%03lds user %ldh%02ldm%02ld.%03lds sys %ldh%02ldm%02ld.%03lds\n",
secs / 3600,
(secs % 3600) / 60,
secs % 60,
suseconds / 1000,
ru->ru_utime.tv_sec / 3600,
(ru->ru_utime.tv_sec % 3600) / 60,
ru->ru_utime.tv_sec% 60,
(long)(ru->ru_utime.tv_usec / 1000),
ru->ru_stime.tv_sec / 3600,
(ru->ru_stime.tv_sec % 3600) / 60,
ru->ru_stime.tv_sec% 60,
(long)(ru->ru_stime.tv_usec / 1000)
);
}
static void
process_smpl_buf(smpl_hdr_t *hdr, uint64_t *smpl_pmds, unsigned int num_smpl_pmds, size_t entry_size)
{
static uint64_t last_overflow = ~0; /* initialize to biggest value possible */
static uint64_t last_count;
smpl_entry_t *ent;
size_t pos, count;
uint64_t entry, *reg;
unsigned int j, n;
if (hdr->hdr_overflows == last_overflow && hdr->hdr_count == last_count) {
warning("skipping identical set of samples %"PRIu64" = %"PRIu64"\n",
hdr->hdr_overflows, last_overflow);
return;
}
count = hdr->hdr_count;
if (options.opt_no_show) {
collected_samples += count;
return;
}
ent = (smpl_entry_t *)(hdr+1);
pos = (unsigned long)ent;
entry = collected_samples;
while(count--) {
printf("entry %"PRIu64" PID:%d TID:%d CPU:%d LAST_VAL:%"PRIu64" IIP:0x%llx\n",
entry,
ent->tgid,
ent->pid,
ent->cpu,
-ent->last_reset_val,
(unsigned long long)ent->ip);
/*
* print body: additional PMDs recorded
* PMD are recorded in increasing index order
*/
reg = (uint64_t *)(ent+1);
n = num_smpl_pmds;
for(j=0; n; j++) {
if (pfm_bv_isset(smpl_pmds, j)) {
printf("PMD%-3d:0x%016"PRIx64"\n", j, *reg);
reg++;
n--;
}
}
pos += entry_size;
ent = (smpl_entry_t *)pos;
entry++;
}
collected_samples = entry;
last_overflow = hdr->hdr_overflows;
if (last_count != hdr->hdr_count && (last_count || last_overflow == 0))
collected_partial += hdr->hdr_count;
last_count = hdr->hdr_count;
}
int
mainloop(char **arg)
{
smpl_hdr_t *hdr;
smpl_arg_t buf_arg;
pfmlib_input_param_t inp;
pfmlib_output_param_t outp;
pfarg_pmd_attr_t pd[NUM_PMDS];
pfarg_pmr_t pc[NUM_PMCS];
pfarg_sinfo_t sif;
struct timeval start_time, end_time;
struct rusage rusage;
pfarg_msg_t msg;
uint64_t ovfl_count = 0;
uint32_t ctx_flags;
size_t entry_size;
void *buf_addr;
pid_t pid;
int status, ret, fd;
unsigned int i, num_counters;
unsigned int max_pmd = 0, num_smpl_pmds = 0;
/*
* intialize all locals
*/
memset(&buf_arg, 0, sizeof(buf_arg));
memset(&inp,0, sizeof(inp));
memset(&outp,0, sizeof(outp));
memset(pd, 0, sizeof(pd));
memset(pc, 0, sizeof(pc));
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;
/*
* 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.
*/
get_sif(0, &sif);
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));
/*
* Now prepare the argument to initialize the PMDs and PMCS.
* We use pfp_pmc_count to determine the number of PMC to intialize.
* We use pfp_pmd_count to determine the number of PMD to initialize.
* Some events/features may cause extra PMCs to be used, leading to:
* - pfp_pmc_count may be >= pfp_event_count
* - pfp_pmd_count may 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 < outp.pfp_pmd_count; i++) {
pd[i].reg_num = outp.pfp_pmds[i].reg_num;
/*
* skip first counter (sampling period)
* track highest PMD
*/
if (i) {
pfm_bv_set(pd[0].reg_smpl_pmds, pd[i].reg_num);
if (pd[i].reg_num > max_pmd)
max_pmd = pd[i].reg_num;
num_smpl_pmds++;
}
}
/*
* 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.
*/
pd[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.
*/
pfm_bv_copy(pd[0].reg_reset_pmds, pd[0].reg_smpl_pmds, max_pmd);
pd[0].reg_value = - SAMPLING_PERIOD;
pd[0].reg_short_reset = - SAMPLING_PERIOD;
pd[0].reg_long_reset = - SAMPLING_PERIOD;
/*
* setup randomization parameters, we allow a range of up to +256 here.
*/
pd[0].reg_random_mask = 0xff;
/*
* 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)+(num_smpl_pmds<<3);
printf("programming %u PMCS and %u PMDS\n", outp.pfp_pmc_count, inp.pfp_event_count);
/*
* indicate we are using a smapling format, i.e., extra arguments
* passed to pfm_create_session()
*/
ctx_flags = PFM_FL_SMPL_FMT;
/*
* add overflow blocking is necessary
*/
ctx_flags |= options.opt_block ? PFM_FL_NOTIFY_BLOCK : 0;
/*
* 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.
*/
buf_arg.buf_size = 3*getpagesize()+512;
/*
* now create our session
*/
fd = pfm_create(ctx_flags, NULL, FMT_NAME, &buf_arg, sizeof(buf_arg));
if (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));
}
/*
* retrieve the virtual address at which the sampling
* buffer has been mapped
*/
buf_addr = mmap(NULL, (size_t)buf_arg.buf_size, PROT_READ, MAP_PRIVATE, fd, 0);
if (buf_addr == MAP_FAILED)
fatal_error("cannot mmap sampling buffer: %s\n", strerror(errno));
printf("buffer mapped @%p\n", buf_addr);
hdr = (smpl_hdr_t *)buf_addr;
printf("hdr_cur_offs=%llu version=%u.%u\n",
(unsigned long long)hdr->hdr_cur_offs,
PFM_VERSION_MAJOR(hdr->hdr_version),
PFM_VERSION_MINOR(hdr->hdr_version));
if (PFM_VERSION_MAJOR(hdr->hdr_version) < 1)
fatal_error("invalid buffer format version\n");
/*
* Now program the registers
*/
if (pfm_write(fd, 0, PFM_RW_PMC, pc, outp.pfp_pmc_count * sizeof(*pc)))
fatal_error("pfm_write error errno %d\n",errno);
/*
* initialize the PMDs
* To be read, each PMD must be either written or declared
* as being part of a sample (reg_smpl_pmds, reg_reset_pmds)
*/
if (pfm_write(fd, 0, PFM_RW_PMD_ATTR, pd, outp.pfp_pmd_count * sizeof(*pd)))
fatal_error("pfm_write(PMD) error 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 session. 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 session to stopped task
*/
if (pfm_attach(fd, 0, pid))
fatal_error("pfm_attach error errno %d\n",errno);
/*
* activate monitoring for stopped task.
* (nothing will be measured at this point
*/
if (pfm_set_state(fd, 0, PFM_ST_START))
fatal_error("pfm_set_state(start) error errno %d\n",errno);
/*
* detach child. Side effect includes
* activation of monitoring.
*/
ptrace(PTRACE_DETACH, pid, NULL, 0);
gettimeofday(&start_time, NULL);
/*
* core loop
*/
for(;;) {
/*
* wait for overflow/end notification messages
*/
ret = read(fd, &msg, sizeof(msg));
if (ret == -1) {
if(ret == -1 && errno == EINTR) {
warning("read interrupted, retrying\n");
continue;
}
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(hdr, pd[0].reg_smpl_pmds, num_smpl_pmds, entry_size);
ovfl_count++;
/*
* 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 (pfm_set_state(fd, 0, PFM_ST_RESTART)) {
if (errno != EBUSY)
fatal_error("pfm_set_state(restart) error errno %d\n",errno);
else
warning("pfm_set_state(restart): task probably terminated \n");
}
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
*/
wait4(pid, &status, 0, &rusage);
gettimeofday(&end_time, NULL);
/*
* check for any leftover samples
*/
process_smpl_buf(hdr, pd[0].reg_smpl_pmds, num_smpl_pmds, entry_size);
/*
* close file descritor. Because of mmap() the number of reference to the
* "file" is 2, thus the session is only freed when the last reference is closed
* either by closed or munmap() depending on the order in which those calls are
* made:
* - close() -> munmap(): session and buffer destroyed after munmap().
* buffer remains accessible after close().
* - munmap() -> close(): buffer unaccessible after munmap(), session and
* buffer destroyed after close().
*
* It is important to free the resources cleanly, especially because the sampling
* buffer reserves locked memory.
*/
close(fd);
/*
* unmap buffer, actually free the buffer and session because placed after
* the close(), i.e. is the last reference. See comments about close() above.
*/
ret = munmap(hdr, (size_t)buf_arg.buf_size);
if (ret)
fatal_error("cannot unmap buffer: %s\n", strerror(errno));
printf("%"PRIu64" samples (%"PRIu64" in partial buffer) collected in %"PRIu64" buffer overflows\n",
collected_samples,
collected_partial,
ovfl_count);
show_task_rusage(&start_time, &end_time, &rusage);
return 0;
}
static void
usage(void)
{
printf("usage: task_smpl [-h] [--help] [--no-show] [--ovfl-block] cmd\n");
}
int
main(int argc, char **argv)
{
pfmlib_options_t pfmlib_options;
int c, ret;
while ((c=getopt_long(argc, argv,"h", the_options, 0)) != -1) {
switch(c) {
case 0: continue;
case 1:
case 'h':
usage();
exit(0);
default:
fatal_error("");
}
}
if (argv[optind] == NULL) {
fatal_error("You must specify a command to execute\n");
}
/*
* 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 = 1; /* set to 1 for verbose */
pfm_set_options(&pfmlib_options);
/*
* Initialize pfm library (required before we can use it)
*/
ret = pfm_initialize();
if (ret != PFMLIB_SUCCESS)
fatal_error("Cannot initialize library: %s\n", pfm_strerror(ret));
return mainloop(argv+optind);
}