/*
* mont_btb.c - example of how use the ETB with the Dual-Core Itanium 2 PMU
*
* Copyright (c) 2005-2006 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.
*
* This file is part of libpfm, a performance monitoring support library for
* applications on Linux.
*/
#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 <fcntl.h>
#include <sys/mman.h>
#include <perfmon/perfmon.h>
#include <perfmon/perfmon_dfl_smpl.h>
#include <perfmon/pfmlib_montecito.h>
typedef pfm_dfl_smpl_hdr_t etb_hdr_t;
typedef pfm_dfl_smpl_entry_t etb_entry_t;
typedef pfm_dfl_smpl_arg_t smpl_arg_t;
#define NUM_PMCS PFMLIB_MAX_PMCS
#define NUM_PMDS PFMLIB_MAX_PMDS
#define MAX_EVT_NAME_LEN 128
#define MAX_PMU_NAME_LEN 32
/*
* The ETB_EVENT is increment by 1 for each branch event. Such event is composed of
* two entries in the ETB: a source and a target entry. The ETB is full after 4 branch
* events.
*/
#define SMPL_PERIOD (4UL*256)
/*
* We use a small buffer size to exercise the overflow handler
*/
#define SMPL_BUF_NENTRIES 64
static void *smpl_vaddr;
static size_t entry_size;
static int id;
#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));
}
/*
* we don't use static to make sure the compiler does not inline the function
*/
long func1(void) { return random();}
long func2(void) { return random();}
long
do_test(unsigned long loop)
{
long sum = 0;
while(loop--) {
if (loop & 0x1)
sum += func1();
else
sum += loop + func2();
}
return sum;
}
static void fatal_error(char *fmt,...) __attribute__((noreturn));
static void
fatal_error(char *fmt, ...)
{
va_list ap;
va_start(ap, fmt);
vfprintf(stderr, fmt, ap);
va_end(ap);
exit(1);
}
/*
* print content of sampling buffer
*
* XXX: using stdio to print from a signal handler is not safe with multi-threaded
* applications
*/
#define safe_printf printf
static void
show_etb_reg(int j, pfm_mont_pmd_reg_t reg, pfm_mont_pmd_reg_t pmd39)
{
unsigned long bruflush, b1, etb_ext;
unsigned long addr;
int is_valid;
is_valid = reg.pmd48_63_etb_mont_reg.etb_s == 0 && reg.pmd48_63_etb_mont_reg.etb_mp == 0 ? 0 : 1;
/*
* the joy of the ETB extension register layout!
*/
if (j < 8)
etb_ext = (pmd39.pmd_val>>(8*j)) & 0xf;
else
etb_ext = (pmd39.pmd_val>>(4+8*(j-8))) & 0xf;
b1 = etb_ext & 0x1;
bruflush = (etb_ext >> 1) & 0x1;
safe_printf("\tPMD%-2d: 0x%016lx s=%d mp=%d bru=%ld b1=%ld valid=%c\n",
j+48,
reg.pmd_val,
reg.pmd48_63_etb_mont_reg.etb_s,
reg.pmd48_63_etb_mont_reg.etb_mp,
bruflush, b1,
is_valid ? 'Y' : 'N');
if (!is_valid) return;
if (reg.pmd48_63_etb_mont_reg.etb_s) {
addr = (reg.pmd48_63_etb_mont_reg.etb_addr+b1)<<4;
addr |= reg.pmd48_63_etb_mont_reg.etb_slot < 3 ? reg.pmd48_63_etb_mont_reg.etb_slot : 0;
safe_printf("\t Source Address: 0x%016lx\n"
"\t Taken=%c Prediction:%s\n\n",
addr,
reg.pmd48_63_etb_mont_reg.etb_slot < 3 ? 'Y' : 'N',
reg.pmd48_63_etb_mont_reg.etb_mp ? "FE Failure" :
bruflush ? "BE Failure" : "Success");
} else {
safe_printf("\t Target Address:0x%016lx\n\n",
(unsigned long)(reg.pmd48_63_etb_mont_reg.etb_addr<<4));
}
}
static void
show_etb(pfm_mont_pmd_reg_t *etb)
{
int i, last;
pfm_mont_pmd_reg_t pmd38, pmd39;
pmd38.pmd_val = etb[0].pmd_val;
pmd39.pmd_val = etb[1].pmd_val;
i = pmd38.pmd38_mont_reg.etbi_full ? pmd38.pmd38_mont_reg.etbi_ebi : 0;
last = pmd38.pmd38_mont_reg.etbi_ebi;
safe_printf("btb_trace: i=%d last=%d bbi=%d full=%d\n",
i,
last,
pmd38.pmd38_mont_reg.etbi_ebi,
pmd38.pmd38_mont_reg.etbi_full);
/*
* i+2 = skip over PMD38/pmd39
*/
do {
show_etb_reg(i, etb[i+2], pmd39);
i = (i+1) % 16;
} while (i != last);
}
void
process_smpl_buffer(void)
{
etb_hdr_t *hdr;
etb_entry_t *ent;
unsigned long pos;
unsigned long smpl_entry = 0;
pfm_mont_pmd_reg_t *reg;
size_t count;
static unsigned long last_ovfl = ~0UL;
hdr = (etb_hdr_t *)smpl_vaddr;
/*
* check that we are not diplaying the previous set of samples again.
* Required to take care of the last batch of samples.
*/
if (hdr->hdr_overflows <= last_ovfl && last_ovfl != ~0UL) {
printf("skipping identical set of samples %lu <= %lu\n", hdr->hdr_overflows, last_ovfl);
return;
}
pos = (unsigned long)(hdr+1);
count = hdr->hdr_count;
/*
* walk through all the entries recored in the buffer
*/
while(count--) {
ent = (etb_entry_t *)pos;
/*
* print entry header
*/
safe_printf("Entry %ld PID:%d TID:%d CPU:%d STAMP:0x%lx IIP:0x%016lx\n",
smpl_entry++,
ent->tgid,
ent->pid,
ent->cpu,
ent->tstamp,
ent->ip);
/*
* point to first recorded register (always contiguous with entry header)
*/
reg = (pfm_mont_pmd_reg_t*)(ent+1);
/*
* in this particular example, we have pmd48-pmd63 has the ETB. We have also
* included pmd38/pmd39 (ETB index and extenseion) has part of the registers
* to record. This trick allows us to get the index to decode the sequential
* order of the ETB.
*
* Recorded registers are always recorded in increasing index order. So we know
* that where to find pmd38/pmd39.
*/
show_etb(reg);
/*
* move to next entry
*/
pos += entry_size;
}
}
static void
overflow_handler(int n, struct siginfo *info, struct sigcontext *sc)
{
process_smpl_buffer();
/*
* And resume monitoring
*/
if (pfm_restart(id))
fatal_error("pfm_restart errno %d\n", errno);
}
int
main(void)
{
int ret;
int type = 0;
pfarg_pmr_t pc[NUM_PMCS];
pfarg_pmd_attr_t pd[NUM_PMDS];
pfmlib_input_param_t inp;
pfmlib_output_param_t outp;
pfmlib_mont_input_param_t mont_inp;
smpl_arg_t buf_arg;
pfmlib_options_t pfmlib_options;
struct sigaction act;
unsigned int i;
/*
* 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_MONTECITO_PMU) {
char model[MAX_PMU_NAME_LEN];
pfm_get_pmu_name(model, MAX_PMU_NAME_LEN);
fatal_error("this program does not work with %s PMU\n", model);
}
/*
* Install the overflow handler (SIGIO)
*/
memset(&act, 0, sizeof(act));
act.sa_handler = (sig_t)overflow_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 */
pfmlib_options.pfm_verbose = 0; /* set to 1 for debug */
pfm_set_options(&pfmlib_options);
memset(pc, 0, sizeof(pc));
memset(pd, 0, sizeof(pd));
memset(&buf_arg, 0, sizeof(buf_arg));
/*
* prepare parameters to library. we don't use any Itanium
* specific features here. so the pfp_model is NULL.
*/
memset(&inp,0, sizeof(inp));
memset(&outp,0, sizeof(outp));
memset(&mont_inp,0, sizeof(mont_inp));
/*
* Before calling pfm_find_dispatch(), we must specify what kind
* of branches we want to capture. We are interested in all taken
* branches * therefore we program we set the various fields to:
*/
mont_inp.pfp_mont_etb.etb_used = 1;
mont_inp.pfp_mont_etb.etb_tm = 0x2;
mont_inp.pfp_mont_etb.etb_ptm = 0x3;
mont_inp.pfp_mont_etb.etb_ppm = 0x3;
mont_inp.pfp_mont_etb.etb_brt = 0x0;
mont_inp.pfp_mont_etb.etb_plm = PFM_PLM3;
if (pfm_find_full_event("ETB_EVENT", &inp.pfp_events[0]) != PFMLIB_SUCCESS)
fatal_error("cannot find event ETB_EVENT\n");
/*
* set the (global) 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, &mont_inp, &outp, NULL)) != PFMLIB_SUCCESS)
fatal_error("cannot configure events: %s\n", pfm_strerror(ret));
/*
* 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 = getpagesize();
/*
* now create the session
*/
id = pfm_create(PFM_FL_SMPL_FMT, NULL, "default", &buf_arg, sizeof(buf_arg));
if (id == -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
*/
smpl_vaddr = mmap(NULL, (size_t)buf_arg.buf_size, PROT_READ, MAP_PRIVATE, id, 0);
if (smpl_vaddr == MAP_FAILED)
fatal_error("cannot mmap sampling buffer errno %d\n", errno);
printf("Sampling buffer mapped at %p\n", smpl_vaddr);
/*
* 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 cause extra PMCs to be used, so pfp_pmc_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;
}
/*
* figure out pmd mapping from output pmc
* PMD38 is part of the set of used PMD returned by libpfm.
* It will be reset automatically
*/
for (i=0; i < outp.pfp_pmd_count; i++)
pd[i].reg_num = outp.pfp_pmds[i].reg_num;
/*
* indicate we want notification when buffer is full and randomization
*/
pd[0].reg_flags |= PFM_REGFL_OVFL_NOTIFY | PFM_REGFL_RANDOM;
/*
* Now prepare the argument to initialize the PMD and the sampling period
* We know we use only one PMD in this case, therefore pmd[0] corresponds
* to our first event which is our sampling period.
*/
pd[0].reg_value = - SMPL_PERIOD;
pd[0].reg_long_reset = - SMPL_PERIOD;
pd[0].reg_short_reset = - SMPL_PERIOD;
/*
* populate our smpl_pmds bitmask to include all of the ETB PMDs,
* including index, extensions
*/
pfm_bv_set(pd[0].reg_smpl_pmds, 38);
pfm_bv_set(pd[0].reg_smpl_pmds, 39);
entry_size = sizeof(etb_entry_t) + 2 * 8;
for(i=48; i < 64; i++) {
pfm_bv_set(pd[0].reg_smpl_pmds, i);
entry_size += 8;
}
/*
* When our counter overflows, we want to ETB index to be reset, so that we keep
* in sync.
*/
pfm_bv_set(pd[0].reg_reset_pmds, 38);
/*
* Now program the registers
*/
if (pfm_write(id, 0, PFM_RW_PMC, pc, outp.pfp_pmc_count * sizeof(*pc)))
fatal_error("pfm_write error errno %d\n",errno);
if (pfm_write(id, 0, PFM_RW_PMD_ATTR, pd, outp.pfp_pmd_count * sizeof(*pd)))
fatal_error("pfm_write(PMD) error errno %d\n",errno);
/*
* now we attach session
*/
if (pfm_attach(id, 0, getpid()))
fatal_error("pfm_attach error errno %d\n",errno);
/*
* setup asynchronous notification on the file descriptor
*/
ret = fcntl(id, F_SETFL, fcntl(id, F_GETFL, 0) | O_ASYNC);
if (ret == -1)
fatal_error("cannot set ASYNC: %s\n", strerror(errno));
/*
* get ownership of the descriptor
*/
ret = fcntl(id, F_SETOWN, getpid());
if (ret == -1)
fatal_error("cannot setown: %s\n", strerror(errno));
/*
* Let's roll now.
*/
if (pfm_set_state(id, 0, PFM_ST_START))
fatal_error("pfm_set_state error errno %d\n",errno);
do_test(1000);
if (pfm_set_state(id, 0, PFM_ST_STOP))
fatal_error("pfm_set_state error errno %d\n",errno);
/*
* We must call the processing routine to cover the last entries recorded
* in the sampling buffer. Note that the buffer may not be full at this point.
*
*/
process_smpl_buffer();
/*
* let's stop this now
*/
munmap(smpl_vaddr, (size_t)buf_arg.buf_size);
close(id);
return 0;
}