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/*
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* task_attach.c - example of how to attach to another task for monitoring
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577717 |
*
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577717 |
* Copyright (c) 2002-2006 Hewlett-Packard Development Company, L.P.
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577717 |
* Contributed by Stephane Eranian <eranian@hpl.hp.com>
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577717 |
*
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577717 |
* Permission is hereby granted, free of charge, to any person obtaining a copy
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577717 |
* of this software and associated documentation files (the "Software"), to deal
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577717 |
* in the Software without restriction, including without limitation the rights
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577717 |
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
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577717 |
* of the Software, and to permit persons to whom the Software is furnished to do so,
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577717 |
* subject to the following conditions:
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577717 |
*
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577717 |
* The above copyright notice and this permission notice shall be included in all
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577717 |
* copies or substantial portions of the Software.
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577717 |
*
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577717 |
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
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577717 |
* INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
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577717 |
* PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
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577717 |
* HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF
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577717 |
* CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE
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577717 |
* OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
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577717 |
*/
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577717 |
#include <sys/types.h>
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577717 |
#include <inttypes.h>
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577717 |
#include <stdio.h>
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577717 |
#include <stdlib.h>
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577717 |
#include <stdarg.h>
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577717 |
#include <errno.h>
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577717 |
#include <unistd.h>
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577717 |
#include <string.h>
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577717 |
#include <stdarg.h>
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#include <sys/wait.h>
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577717 |
#include <sys/ptrace.h>
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577717 |
|
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#include <perfmon/pfmlib.h>
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#include <perfmon/perfmon.h>
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577717 |
#include "detect_pmcs.h"
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|
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#define NUM_PMCS PFMLIB_MAX_PMCS
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577717 |
#define NUM_PMDS PFMLIB_MAX_PMDS
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577717 |
|
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577717 |
#define MAX_EVT_NAME_LEN 128
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577717 |
static void fatal_error(char *fmt,...) __attribute__((noreturn));
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|
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static void
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fatal_error(char *fmt, ...)
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577717 |
{
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577717 |
va_list ap;
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577717 |
|
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577717 |
va_start(ap, fmt);
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577717 |
vfprintf(stderr, fmt, ap);
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577717 |
va_end(ap);
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exit(1);
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}
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|
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int
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parent(pid_t pid)
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{
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577717 |
pfmlib_input_param_t inp;
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577717 |
pfmlib_output_param_t outp;
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pfarg_pmr_t pc[NUM_PMCS];
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577717 |
pfarg_pmr_t pd[NUM_PMDS];
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pfarg_sinfo_t sif;
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pfarg_msg_t msg;
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577717 |
unsigned int i, num_counters;
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577717 |
int status, ret;
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577717 |
int ctx_fd;
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577717 |
char name[MAX_EVT_NAME_LEN];
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577717 |
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577717 |
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577717 |
memset(pc, 0, sizeof(pc));
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memset(pd, 0, sizeof(pd));
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577717 |
memset(&inp,0, sizeof(inp));
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577717 |
memset(&outp,0, sizeof(outp));
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577717 |
memset(&sif,0, sizeof(sif));
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pfm_get_num_counters(&num_counters);
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577717 |
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if (pfm_get_cycle_event(&inp.pfp_events[0]) != PFMLIB_SUCCESS)
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577717 |
fatal_error("cannot find cycle event\n");
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577717 |
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577717 |
if (pfm_get_inst_retired_event(&inp.pfp_events[1]) != PFMLIB_SUCCESS)
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577717 |
fatal_error("cannot find inst retired event\n");
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577717 |
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577717 |
i = 2;
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577717 |
|
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577717 |
/*
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577717 |
* set the privilege mode:
|
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577717 |
* PFM_PLM3 : user level
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577717 |
* PFM_PLM0 : kernel level
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577717 |
*/
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577717 |
inp.pfp_dfl_plm = PFM_PLM3;
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577717 |
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577717 |
if (i > num_counters) {
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577717 |
i = num_counters;
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577717 |
printf("too many events provided (max=%d events), using first %d event(s)\n", num_counters, i);
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|
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577717 |
}
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577717 |
|
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577717 |
/*
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577717 |
* how many counters we use
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577717 |
*/
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577717 |
inp.pfp_event_count = i;
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577717 |
|
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577717 |
/*
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577717 |
* now create a session. we will later attach it to the task we are creating.
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|
Packit |
577717 |
*/
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|
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577717 |
ctx_fd = pfm_create(0, &sif;;
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|
Packit |
577717 |
if (ctx_fd == -1) {
|
|
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577717 |
if (errno == ENOSYS) {
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|
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577717 |
fatal_error("Your kernel does not have performance monitoring support!\n");
|
|
Packit |
577717 |
}
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|
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577717 |
fatal_error("cannot create session %s\n", strerror(errno));
|
|
Packit |
577717 |
}
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|
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/*
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|
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* build the pfp_unavail_pmcs bitmask by looking
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|
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577717 |
* at what perfmon has available. It is not always
|
|
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577717 |
* the case that all PMU registers are actually available
|
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* to applications. For instance, on IA-32 platforms, some
|
|
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577717 |
* registers may be reserved for the NMI watchdog timer.
|
|
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577717 |
*
|
|
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577717 |
* With this bitmap, the library knows which registers NOT to
|
|
Packit |
577717 |
* use. Of source, it is possible that no valid assignement may
|
|
Packit |
577717 |
* be possible if certina PMU registers are not available.
|
|
Packit |
577717 |
*/
|
|
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577717 |
detect_unavail_pmu_regs(&sif, &inp.pfp_unavail_pmcs, NULL);
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577717 |
|
|
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577717 |
/*
|
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577717 |
* let the library figure out the values for the PMCS
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Packit |
577717 |
*/
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577717 |
if ((ret=pfm_dispatch_events(&inp, NULL, &outp, NULL)) != PFMLIB_SUCCESS) {
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|
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577717 |
fatal_error("cannot configure events: %s\n", pfm_strerror(ret));
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|
Packit |
577717 |
}
|
|
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577717 |
/*
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577717 |
* Now prepare the argument to initialize the PMDs and PMCS.
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|
Packit |
577717 |
* We must pfp_pmc_count to determine the number of PMC to intialize.
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|
Packit |
577717 |
* We must use pfp_event_count to determine the number of PMD to initialize.
|
|
Packit |
577717 |
* Some events causes extra PMCs to be used, so pfp_pmc_count may be >= pfp_event_count.
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|
Packit |
577717 |
*
|
|
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577717 |
* This step is new compared to libpfm-2.x. It is necessary because the library no
|
|
Packit |
577717 |
* longer knows about the kernel data structures.
|
|
Packit |
577717 |
*/
|
|
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577717 |
for (i=0; i < outp.pfp_pmc_count; i++) {
|
|
Packit |
577717 |
pc[i].reg_num = outp.pfp_pmcs[i].reg_num;
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|
Packit |
577717 |
pc[i].reg_value = outp.pfp_pmcs[i].reg_value;
|
|
Packit |
577717 |
}
|
|
Packit |
577717 |
for(i=0; i < outp.pfp_pmd_count; i++)
|
|
Packit |
577717 |
pd[i].reg_num = outp.pfp_pmds[i].reg_num;
|
|
Packit |
577717 |
|
|
Packit |
577717 |
/*
|
|
Packit |
577717 |
* Now program the registers
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Packit |
577717 |
*
|
|
Packit |
577717 |
* We don't use the save variable to indicate the number of elements passed to
|
|
Packit |
577717 |
* the kernel because, as we said earlier, pc may contain more elements than
|
|
Packit |
577717 |
* the number of events we specified, i.e., contains more thann counting monitors.
|
|
Packit |
577717 |
*/
|
|
Packit |
577717 |
|
|
Packit |
577717 |
if (pfm_write(ctx_fd, 0, PFM_RW_PMC, pc, outp.pfp_pmc_count * sizeof(*pc)) == -1)
|
|
Packit |
577717 |
fatal_error("pfm_write error errno %d\n",errno);
|
|
Packit |
577717 |
|
|
Packit |
577717 |
/*
|
|
Packit |
577717 |
* To be read, each PMD must be either written or declared
|
|
Packit |
577717 |
* as being part of a sample (reg_smpl_pmds)
|
|
Packit |
577717 |
*/
|
|
Packit |
577717 |
if (pfm_write(ctx_fd, 0, PFM_RW_PMD, pd, outp.pfp_pmd_count * sizeof(*pd)) == -1)
|
|
Packit |
577717 |
fatal_error("pfm_write(PMD) error errno %d\n",errno);
|
|
Packit |
577717 |
|
|
Packit |
577717 |
ret = ptrace(PTRACE_ATTACH, pid, NULL, 0);
|
|
Packit |
577717 |
if (ret == -1) {
|
|
Packit |
577717 |
fatal_error("cannot attach to %d: %s\n", pid, strerror(errno));
|
|
Packit |
577717 |
}
|
|
Packit |
577717 |
|
|
Packit |
577717 |
/*
|
|
Packit |
577717 |
* wait for the child to be actually stopped
|
|
Packit |
577717 |
*/
|
|
Packit |
577717 |
waitpid(pid, &status, WUNTRACED);
|
|
Packit |
577717 |
|
|
Packit |
577717 |
/*
|
|
Packit |
577717 |
* check if process exited early
|
|
Packit |
577717 |
*/
|
|
Packit |
577717 |
if (WIFEXITED(status))
|
|
Packit |
577717 |
fatal_error("command process %d exited too early with status %d\n", pid, WEXITSTATUS(status));
|
|
Packit |
577717 |
|
|
Packit |
577717 |
/*
|
|
Packit |
577717 |
* the task is stopped at this point
|
|
Packit |
577717 |
*/
|
|
Packit |
577717 |
|
|
Packit |
577717 |
/*
|
|
Packit |
577717 |
* now we attach the session to ourself
|
|
Packit |
577717 |
*/
|
|
Packit |
577717 |
if (pfm_attach(ctx_fd, 0, pid) == -1)
|
|
Packit |
577717 |
fatal_error("pfm_attach error errno %d\n",errno);
|
|
Packit |
577717 |
|
|
Packit |
577717 |
/*
|
|
Packit |
577717 |
* activate monitoring. The task is still STOPPED at this point. Monitoring
|
|
Packit |
577717 |
* will not take effect until the execution of the task is resumed.
|
|
Packit |
577717 |
*/
|
|
Packit |
577717 |
if (pfm_set_state(ctx_fd, 0, PFM_ST_START) == -1)
|
|
Packit |
577717 |
fatal_error("pfm_set_state(start) error errno %d\n",errno);
|
|
Packit |
577717 |
|
|
Packit |
577717 |
/*
|
|
Packit |
577717 |
* now resume execution of the task, effectively activating
|
|
Packit |
577717 |
* monitoring.
|
|
Packit |
577717 |
*/
|
|
Packit |
577717 |
ptrace(PTRACE_DETACH, pid, NULL, 0);
|
|
Packit |
577717 |
|
|
Packit |
577717 |
/*
|
|
Packit |
577717 |
* now the task is running
|
|
Packit |
577717 |
*/
|
|
Packit |
577717 |
|
|
Packit |
577717 |
/*
|
|
Packit |
577717 |
* We cannot simply do a waitpid() because we may be attaching to a process
|
|
Packit |
577717 |
* totally unrelated to our program. Instead we use a perfmon facility that
|
|
Packit |
577717 |
* notifies us when the monitoring task is exiting.
|
|
Packit |
577717 |
*
|
|
Packit |
577717 |
* When a task with a monitoring session attached to it exits, a PFM_MSG_END
|
|
Packit |
577717 |
* is generated. It can be retrieve with a simple read() on the session's descriptor.
|
|
Packit |
577717 |
*
|
|
Packit |
577717 |
* Another reason why you might return from the read is if there was a counter
|
|
Packit |
577717 |
* overflow, unlikely in this example.
|
|
Packit |
577717 |
*
|
|
Packit |
577717 |
* To measure only for short period of time, use select or poll with a timeout,
|
|
Packit |
577717 |
* see task_attach_timeout.c
|
|
Packit |
577717 |
*
|
|
Packit |
577717 |
*/
|
|
Packit |
577717 |
ret = read(ctx_fd, &msg, sizeof(msg));
|
|
Packit |
577717 |
if (ret == -1)
|
|
Packit |
577717 |
fatal_error("cannot read from descriptor: %s\n", strerror(errno));
|
|
Packit |
577717 |
|
|
Packit |
577717 |
if (msg.type != PFM_MSG_END)
|
|
Packit |
577717 |
fatal_error("unexpected msg type : %d\n", msg.type);
|
|
Packit |
577717 |
|
|
Packit |
577717 |
/*
|
|
Packit |
577717 |
* the task has exited, we can simply read the results
|
|
Packit |
577717 |
*/
|
|
Packit |
577717 |
|
|
Packit |
577717 |
/*
|
|
Packit |
577717 |
* now simply read the results.
|
|
Packit |
577717 |
*/
|
|
Packit |
577717 |
if (pfm_read(ctx_fd, 0, PFM_RW_PMD, pd, inp.pfp_event_count * sizeof(*pd)) == -1)
|
|
Packit |
577717 |
fatal_error("pfm_read error errno %d\n",errno);
|
|
Packit |
577717 |
|
|
Packit |
577717 |
/*
|
|
Packit |
577717 |
* print the results
|
|
Packit |
577717 |
*
|
|
Packit |
577717 |
* It is important to realize, that the first event we specified may not
|
|
Packit |
577717 |
* be in PMD4. Not all events can be measured by any monitor. That's why
|
|
Packit |
577717 |
* we need to use the pc[] array to figure out where event i was allocated.
|
|
Packit |
577717 |
*
|
|
Packit |
577717 |
*/
|
|
Packit |
577717 |
for (i=0; i < inp.pfp_event_count; i++) {
|
|
Packit |
577717 |
pfm_get_full_event_name(&inp.pfp_events[i], name, MAX_EVT_NAME_LEN);
|
|
Packit |
577717 |
printf("PMD%-3u %20"PRIu64" %s\n",
|
|
Packit |
577717 |
pd[i].reg_num,
|
|
Packit |
577717 |
pd[i].reg_value,
|
|
Packit |
577717 |
name);
|
|
Packit |
577717 |
}
|
|
Packit |
577717 |
/*
|
|
Packit |
577717 |
* free the session
|
|
Packit |
577717 |
*/
|
|
Packit |
577717 |
close(ctx_fd);
|
|
Packit |
577717 |
|
|
Packit |
577717 |
return 0;
|
|
Packit |
577717 |
}
|
|
Packit |
577717 |
|
|
Packit |
577717 |
int
|
|
Packit |
577717 |
main(int argc, char **argv)
|
|
Packit |
577717 |
{
|
|
Packit |
577717 |
pfmlib_options_t pfmlib_options;
|
|
Packit |
577717 |
pid_t pid;
|
|
Packit |
577717 |
int ret;
|
|
Packit |
577717 |
|
|
Packit |
577717 |
if (argc < 2) {
|
|
Packit |
577717 |
fatal_error("usage: %s pid\n", argv[0]);
|
|
Packit |
577717 |
}
|
|
Packit |
577717 |
|
|
Packit |
577717 |
pid = atoi(argv[1]);
|
|
Packit |
577717 |
|
|
Packit |
577717 |
/*
|
|
Packit |
577717 |
* pass options to library (optional)
|
|
Packit |
577717 |
*/
|
|
Packit |
577717 |
memset(&pfmlib_options, 0, sizeof(pfmlib_options));
|
|
Packit |
577717 |
pfmlib_options.pfm_debug = 0; /* set to 1 for debug */
|
|
Packit |
577717 |
pfm_set_options(&pfmlib_options);
|
|
Packit |
577717 |
|
|
Packit |
577717 |
/*
|
|
Packit |
577717 |
* Initialize pfm library (required before we can use it)
|
|
Packit |
577717 |
*/
|
|
Packit |
577717 |
ret = pfm_initialize();
|
|
Packit |
577717 |
if (ret != PFMLIB_SUCCESS)
|
|
Packit |
577717 |
fatal_error("Cannot initialize library: %s\n", pfm_strerror(ret));
|
|
Packit |
577717 |
|
|
Packit |
577717 |
return parent(pid);
|
|
Packit |
577717 |
}
|