syst_smp.c

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/*
 * syst_smp.c - system-wide monitoring for SMP machine using libpfms helper
 * library
 *
 * Copyright (c) 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 <unistd.h>
#include <string.h>
#include <pthread.h>
#include <inttypes.h>
#include <errno.h>
#include <stdarg.h>
 
#include <perfmon/perfmon.h>
#include <perfmon/pfmlib.h>
 
#include <libpfms.h>
 
 
#define NUM_PMCS PFMLIB_MAX_PMCS
#define NUM_PMDS PFMLIB_MAX_PMDS
 
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);
}
 
static uint32_t
popcount(uint64_t c)
{
    uint32_t count = 0;
 
    for(; c; c>>=1) {
        if (c & 0x1)
            count++;
    }
    return count;
}
 
int
main(int argc, char **argv)
{
    pfarg_ctx_t ctx;
    pfarg_pmc_t pc[NUM_PMCS];
    pfarg_pmd_t *pd;
    pfmlib_input_param_t inp;
    pfmlib_output_param_t outp;
    uint64_t cpu_list;
    void *desc;
    unsigned int num_counters;
    uint32_t i, j, l, k, ncpus, npmds;
    size_t len;
    int ret;
    char *name;
 
    if (pfm_initialize() != PFMLIB_SUCCESS)
        fatal_error("cannot initialize libpfm\n");
 
    if (pfms_initialize())
        fatal_error("cannot initialize libpfms\n");
 
    memset(&ctx, 0, sizeof(ctx));
    memset(pc, 0, sizeof(pc));
 
    ncpus = (uint32_t)sysconf(_SC_NPROCESSORS_ONLN);
    if (ncpus == -1)
        fatal_error("cannot retrieve number of online processors\n");
 
    if (argc > 1) {
        cpu_list = strtoul(argv[1],NULL,0);
        if (popcount(cpu_list) > ncpus)
            fatal_error("too many processors specified\n");
    } else {
        cpu_list = ((1<<ncpus)-1);
    }
 
    /*
     * use libpfm to prepare some decent PMC/PMD setup
     */
    memset(&inp,0, sizeof(inp));
    memset(&outp,0, sizeof(outp));
 
    pfm_get_num_counters(&num_counters);
    pfm_get_max_event_name_len(&len);
 
    name = malloc(len+1);
    if (name == NULL)
        fatal_error("cannot allocate memory for event name\n");
 
 
    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;
 
    inp.pfp_dfl_plm = PFM_PLM3|PFM_PLM0;
 
    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;
 
    /*
     * indicate we are using the monitors for a system-wide session.
     * This may impact the way the library sets up the PMC values.
     */
    inp.pfp_flags = PFMLIB_PFP_SYSTEMWIDE;
 
    /*
     * 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));
 
 
    npmds = ncpus * inp.pfp_event_count;
 
    printf("ncpus=%u npmds=%u\n", ncpus, npmds);
 
    pd = calloc(npmds, sizeof(pfarg_pmd_t));
    if (pd == NULL)
        fatal_error("cannot allocate pd array\n");
 
    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;
    }
 
    /*
     * We use inp.pfp_event_count PMD registers for our events per-CPU.
     * We need to setup the PMDs we use. They are determined based on the
     * PMC registers used. The following loop prepares the pd[] array
     * for pfm_write_pmds(). With libpfms, on PMD write we need to pass
     * only pfp_event_count PMD registers. But on PMD read, we need
     * to pass pfp_event_count PMD registers per-CPU because libpfms
     * does not aggregate counts. To prepapre for PMD read, we therefore
     * propagate the PMD setup beyond just the first pfp_event_count
     * elements of pd[].
     */
    for(l=0, k= 0; l < ncpus; l++) {
        for (i=0; i < outp.pfp_pmd_count; i++, k++)
            pd[k].reg_num   = outp.pfp_pmds[i].reg_num;
    }
 
    /*
     * create a context on all CPUs we asked for
     *
     * libpfms only works for system-wide, so we set the flag in
     * the master context. the context argument is not modified by
     * call.
     *
     * desc is an opaque descriptor used to identify session.
     */
    ctx.ctx_flags = PFM_FL_SYSTEM_WIDE;
 
    ret = pfms_create(&cpu_list, 1, &ctx, NULL, &desc);
    if (ret == -1)
        fatal_error("create error %d\n", ret);
 
    /*
     * program the PMC registers on all CPUs of interest
     */
    ret = pfms_write_pmcs(desc, pc, outp.pfp_pmc_count);
    if (ret == -1)
        fatal_error("write_pmcs error %d\n", ret);
 
    /*
     * program the PMD registers on all CPUs of interest
     */
    ret = pfms_write_pmds(desc, pd, outp.pfp_pmd_count);
    if (ret == -1)
        fatal_error("write_pmds error %d\n", ret);
 
    /*
     * load context on all CPUs of interest
     */
    ret = pfms_load(desc);
    if (ret == -1)
        fatal_error("load error %d\n", ret);
 
    printf("monitoring for 10s on all CPUs\n");
 
    /*
     * start monitoring on all CPUs of interest
     */
    ret = pfms_start(desc);
    if (ret == -1)
        fatal_error("start error %d\n", ret);
 
    /*
     * stop and listen to activity for 10s
     */
    sleep(10);
 
    /*
     * stop monitoring on all CPUs of interest
     */
    ret = pfms_stop(desc);
    if (ret == -1)
        fatal_error("stop error %d\n", ret);
 
    /*
     * read the PMD registers on all CPUs of interest.
     * The pd[] array must be organized such that to
     * read 2 PMDs on each CPU you need:
     *  - 2 * number of CPUs of interest
     *  - the first 2 elements of pd[] read on CPU0
     *  - the next  2 elements of pd[] read on CPU1
     *  - and so on
     */
    ret = pfms_read_pmds(desc, pd, npmds);
    if (ret == -1)
        fatal_error("read_pmds error %d\n", ret);
 
    /*
     * print per-CPU results
     */
    for(j=0, k= 0; j < ncpus; j++) {
        for (i=0; i < inp.pfp_event_count; i++, k++) {
            pfm_get_full_event_name(&inp.pfp_events[i], name, len);
            printf("CPU%-3d PMD%u %20"PRIu64" %s\n",
                    j,
                    pd[k].reg_num,
                    pd[k].reg_value,
                    name);
        }
    }
 
    /*
     * destroy context  on all CPUs of interest.
     * After this call desc is invalid
     */
    ret = pfms_close(desc);
    if (ret == -1)
        fatal_error("close error %d\n", ret);
 
    free(name);
 
    return 0;
}