/*
* mont_irr.c - example of how to use code range restriction 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 <perfmon/perfmon.h>
#include <perfmon/pfmlib_montecito.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
#define VECTOR_SIZE 1000000UL
typedef struct {
char *event_name;
unsigned long expected_value;
} event_desc_t;
static event_desc_t event_list[]={
{ "fp_ops_retired", VECTOR_SIZE<<1 },
{ NULL, 0UL }
};
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);
}
void
saxpy(double *a, double *b, double *c, unsigned long size)
{
unsigned long i;
for(i=0; i < size; i++) {
c[i] = 2*a[i] + b[i];
}
}
void
saxpy2(double *a, double *b, double *c, unsigned long size)
{
unsigned long i;
for(i=0; i < size; i++) {
c[i] = 2*a[i] + b[i];
}
}
static int
do_test(void)
{
unsigned long size;
double *a, *b, *c;
size = VECTOR_SIZE;
a = malloc(size*sizeof(double));
b = malloc(size*sizeof(double));
c = malloc(size*sizeof(double));
if (a == NULL || b == NULL || c == NULL) fatal_error("Cannot allocate vectors\n");
memset(a, 0, size*sizeof(double));
memset(b, 0, size*sizeof(double));
memset(c, 0, size*sizeof(double));
saxpy(a,b,c, size);
saxpy2(a,b,c, size);
return 0;
}
int
main(int argc, char **argv)
{
event_desc_t *p;
unsigned long range_start, range_end;
int ret, type = 0;
pfmlib_input_param_t inp;
pfmlib_output_param_t outp;
pfmlib_mont_input_param_t mont_inp;
pfmlib_mont_output_param_t mont_outp;
pfarg_reg_t pd[NUM_PMDS];
pfarg_reg_t pc[NUM_PMCS];
pfarg_dbreg_t ibrs[8];
pfarg_context_t ctx;
pfarg_load_t load_args;
pfmlib_options_t pfmlib_options;
struct fd { /* function descriptor */
unsigned long addr;
unsigned long gp;
} *fd;
unsigned int i;
int id;
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 family
*/
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);
}
/*
* pass options to library (optional)
*/
memset(&pfmlib_options, 0, sizeof(pfmlib_options));
pfmlib_options.pfm_debug = 1; /* set to 1 for debug */
pfmlib_options.pfm_verbose = 1; /* set to 1 for verbose */
pfm_set_options(&pfmlib_options);
/*
* Compute the range we are interested in
*
* On IA-64, the function pointer does not point directly
* to the function but to a descriptor which contains two
* unsigned long: the first one is the actual start address
* of the function, the second is the gp (global pointer)
* to load into r1 before jumping into the function. Unlesss
* we're jumping into a shared library the gp is the same as
* the current gp.
*
* In the artificial example, we also rely on the compiler/linker
* NOT reordering code layout. We depend on saxpy2() being just
* after saxpy().
*
*/
fd = (struct fd *)saxpy;
range_start = fd->addr;
fd = (struct fd *)saxpy2;
range_end = fd->addr;
memset(pc, 0, sizeof(pc));
memset(pd, 0, sizeof(pd));
memset(&ctx, 0, sizeof(ctx));
memset(ibrs,0, sizeof(ibrs));
memset(&load_args,0, sizeof(load_args));
memset(&inp,0, sizeof(inp));
memset(&outp,0, sizeof(outp));
memset(&mont_inp,0, sizeof(mont_inp));
memset(&mont_outp,0, sizeof(mont_outp));
/*
* find requested event
*/
p = event_list;
for (i=0; p->event_name ; i++, p++) {
if (pfm_find_event(p->event_name, &inp.pfp_events[i].event) != PFMLIB_SUCCESS) {
fatal_error("cannot find %s event\n", p->event_name);
}
}
/*
* set the privilege mode:
* PFM_PLM3 : user level only
*/
inp.pfp_dfl_plm = PFM_PLM3;
/*
* how many counters we use
*/
inp.pfp_event_count = i;
/*
* We use the library to figure out how to program the debug registers
* to cover the data range we are interested in. The rr_end parameter
* must point to the byte after the last element of the range (C-style range).
*
* Because of the masking mechanism and therefore alignment constraints used to implement
* this feature, it may not be possible to exactly cover a given range. It may be that
* the coverage exceeds the desired range. So it is possible to capture noise if
* the surrounding addresses are also heavily used. You can figure out by how much the
* actual range is off compared to the requested range by checking the rr_soff and rr_eoff
* fields on return from the library call.
*
* Upon return, the rr_dbr array is programmed and the number of debug registers (not pairs)
* used to cover the range is in rr_nbr_used.
*
* In the case of code range restriction on Itanium 2, the library will try to use the fine
* mode first and then it will default to using multiple pairs to cover the range.
*/
mont_inp.pfp_mont_irange.rr_used = 1; /* indicate we use code range restriction */
mont_inp.pfp_mont_irange.rr_limits[0].rr_start = range_start;
mont_inp.pfp_mont_irange.rr_limits[0].rr_end = range_end;
/*
* let the library figure out the values for the PMCS
*/
if ((ret=pfm_dispatch_events(&inp, &mont_inp, &outp, &mont_outp)) != PFMLIB_SUCCESS)
fatal_error("cannot configure events: %s\n", pfm_strerror(ret));
/*
* print offsets
*/
printf("code range : [0x%016lx-0x%016lx)\n"
"start_offset:-0x%lx end_offset:+0x%lx\n"
"%d pairs of debug registers used\n",
range_start,
range_end,
mont_outp.pfp_mont_irange.rr_infos[0].rr_soff,
mont_outp.pfp_mont_irange.rr_infos[0].rr_eoff,
mont_outp.pfp_mont_irange.rr_nbr_used >> 1);
/*
* 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 our file descriptor
*/
id = ctx.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 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
*/
for (i=0; i < outp.pfp_pmd_count; i++)
pd[i].reg_num = outp.pfp_pmds[i].reg_num;
/*
* propagate IBR settings. IBRS are mapped to PMC256-PMC263
*/
for (i=0; i < mont_outp.pfp_mont_irange.rr_nbr_used; i++) {
ibrs[i].dbreg_num = mont_outp.pfp_mont_irange.rr_br[i].reg_num;
ibrs[i].dbreg_value = mont_outp.pfp_mont_irange.rr_br[i].reg_value;
}
/*
* 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 coutning monitors.
*/
if (perfmonctl(id, PFM_WRITE_IBRS, ibrs, mont_outp.pfp_mont_irange.rr_nbr_used) == -1)
fatal_error("child: perfmonctl error PFM_WRITE_IBRS errno %d\n",errno);
if (perfmonctl(id, PFM_WRITE_PMCS, pc, outp.pfp_pmc_count))
fatal_error("child: pfm_write_pmcs error errno %d\n",errno);
if (perfmonctl(id, PFM_WRITE_PMDS, pd, outp.pfp_pmd_count) == -1)
fatal_error("child: pfm_write_pmds error 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))
fatal_error("pfm_load_context error errno %d\n",errno);
/*
* Let's roll now.
*
* We run two distinct copies of the same function but we restrict measurement
* to the first one (saxpy). Therefore the expected count is half what you would
* get if code range restriction was not used. The core loop in both case uses
* two floating point operation per iteration.
*/
pfm_self_start(id);
do_test();
pfm_self_stop(id);
/*
* now read the results
*/
if (perfmonctl(id, PFM_READ_PMDS, pd, inp.pfp_event_count) == -1) {
fatal_error( "pfm_read_pmds error errno %d\n",errno);
}
/*
* 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 %20lu %s (expected %lu)\n",
pd[i].reg_num,
pd[i].reg_value,
name, event_list[i].expected_value);
}
/*
* let's stop this now
*/
close(id);
return 0;
}