/*
* ita2_opcode.c - example of how to use the opcode matcher with the Itanium2 PMU
*
* Copyright (c) 2002-2006 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/ia64.
*/
#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 <perfmon/perfmon.h>
#include <perfmon/pfmlib_itanium2.h>
#define NUM_PMCS PFMLIB_MAX_PMCS
#define NUM_PMDS PFMLIB_MAX_PMDS
#define MAX_EVT_NAME_LEN 128
#define MAX_PMU_NAME_LEN 32
/*
* we don't use static to make sure the compiler does not inline the function
*/
int
do_test(unsigned long loop)
{
unsigned long sum = 0;
while(loop--) sum += loop;
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);
}
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;
}