/*

 * syst.c - example of a simple system wide monitoring program

 *

 * 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.

 */

#include <sys/types.h>

#include <inttypes.h>

#include <stdio.h>

#include <stdlib.h>

#include <stdarg.h>

#include <errno.h>

#include <unistd.h>

#include <string.h>

#include <syscall.h>

#include <perfmon/pfmlib.h>

#include <perfmon/perfmon.h>

#include "detect_pmcs.h"

#define NUM_PMCS PFMLIB_MAX_PMCS

#define NUM_PMDS PFMLIB_MAX_PMDS

#define MAX_EVT_NAME_LEN	128

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);

}

/*

 * pin task to CPU

 */

#ifndef __NR_sched_setaffinity

#error "you need to define __NR_sched_setaffinity"

#endif

#define MAX_CPUS	2048

#define NR_CPU_BITS	(MAX_CPUS>>3)

int

pin_cpu(pid_t pid, unsigned int cpu)

{

	uint64_t my_mask[NR_CPU_BITS];

	if (cpu >= MAX_CPUS)

		fatal_error("this program supports only up to %d CPUs\n", MAX_CPUS);

	my_mask[cpu>>6] = 1ULL << (cpu&63);

	return syscall(__NR_sched_setaffinity, pid, sizeof(my_mask), &my_mask);

}

int

main(int argc, char **argv)

{

	char **p;

	pfarg_pmr_t pc[NUM_PMCS];

	pfarg_pmr_t pd[NUM_PMDS];

	pfarg_sinfo_t sif;

	uint64_t pdo[NUM_PMDS];

	pfmlib_input_param_t inp;

	pfmlib_output_param_t outp;

	pfmlib_options_t pfmlib_options;

	unsigned int which_cpu;

	int ret, ctx_fd;

	unsigned int i, l;

	unsigned int num_counters;

	char name[MAX_EVT_NAME_LEN];

	/*

	 * pass options to library (optional)

	 */

	memset(&pfmlib_options, 0, sizeof(pfmlib_options));

	pfmlib_options.pfm_debug = 0; /* set to 1 for debug */

	pfm_set_options(&pfmlib_options);

	/*

	 * Initialize pfm library (required before we can use it)

	 */

	ret = pfm_initialize();

	if (ret != PFMLIB_SUCCESS)

		fatal_error("Cannot initialize library: %s\n", pfm_strerror(ret));

	pfm_get_num_counters(&num_counters);

	memset(pc, 0, sizeof(pc));

	memset(pd, 0, sizeof(pd));

	memset(pdo, 0, sizeof(pdo));

	memset(&inp,0, sizeof(inp));

	memset(&outp,0, sizeof(outp));

	memset(&sif,0, sizeof(sif));

	/*

	 * be nice to user!

	 */

	if (argc > 1) {

		p = argv+1;

		for (i=0; *p ; i++, p++) {

			if (pfm_find_full_event(*p, &inp.pfp_events[i]) != PFMLIB_SUCCESS)

				fatal_error("Cannot find %s event\n", *p);

		}

	} else {

		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;

	}

	/*

	 * set the privilege mode:

	 * 	PFM_PLM3 : user   level

	 * 	PFM_PLM0 : kernel level

	 */

	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;

	/*

	 * pick a random CPU. Assumes CPU are numbered with no holes

	 */

	srandom(getpid());

	which_cpu = random() % sysconf(_SC_NPROCESSORS_ONLN);

	/*

	 * The monitored CPU is determined by the processor core

	 * executing the PFM_LOAD_CONTEXT command. To ensure, we

	 * measure the right core, we pin the thread before making

	 * the call.

	 */

	ret = pin_cpu(getpid(), which_cpu);

	if (ret == -1)

		fatal_error("cannot set affinity to CPU%d: %s\n", which_cpu, strerror(errno));

	/*

	 * after the call the task is pinned to which_cpu

	 */

	/*

	 * now create the system-wide session 

	 */

	ctx_fd = pfm_create(PFM_FL_SYSTEM_WIDE, &sif;;

	if (ctx_fd == -1) {

		if (errno == ENOSYS) {

			fatal_error("Your kernel does not have performance monitoring support!\n");

		}

		fatal_error("cannot create session %s\n", strerror(errno));

	}

	/*

	 * build the pfp_unavail_pmcs bitmask by looking

	 * at what perfmon has available. It is not always

	 * the case that all PMU registers are actually available

	 * to applications. For instance, on IA-32 platforms, some

	 * registers may be reserved for the NMI watchdog timer.

	 *

	 * With this bitmap, the library knows which registers NOT to

	 * use. Of source, it is possible that no valid assignement may

	 * be possible if certina PMU registers  are not available.

	 */

	detect_unavail_pmu_regs(&sif, &inp.pfp_unavail_pmcs, NULL);

	/*

	 * 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));

	/*

	 * Now prepare the argument to initialize the PMDs and PMCS.

	 * We use pfp_pmc_count to determine the number of PMC to intialize.

	 * We use pfp_pmd_count to determine the number of PMD to initialize.

	 * Some events/features may cause extra PMCs to be used, leading to:

	 * 	- pfp_pmc_count may be >= pfp_event_count

	 * 	- pfp_pmd_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;

	}

	for (i=0; i < outp.pfp_pmd_count; i++)

		pd[i].reg_num = outp.pfp_pmds[i].reg_num;

	/*

	 * Now program the registers

	 */

	if (pfm_write(ctx_fd, 0, PFM_RW_PMC, pc, outp.pfp_pmc_count * sizeof(*pc)) == -1)

		fatal_error("pfm_write error errno %d\n",errno);

	if (pfm_write(ctx_fd, 0, PFM_RW_PMD, pd, outp.pfp_pmd_count * sizeof(*pd)) == -1)

		fatal_error("pfm_write(PMDS) error errno %d\n",errno);

	/*

 	 * attach the session to the CPU

	 */

	if (pfm_attach(ctx_fd, 0, which_cpu) == -1)

		fatal_error("pfm_attach error errno %d\n",errno);

	printf("<monitoring started on CPU%d, press CTRL-C to quit before 20s time limit>\n", which_cpu);

	for(l=0; l < 10; l++) {

		/*

		 * start monitoring

		 */

		if (pfm_set_state(ctx_fd, 0, PFM_ST_START) == -1)

			fatal_error("pfm_set_state(start) error errno %d\n",errno);

		sleep(2);

		/*

		 * stop monitoring. 

		 * changed at the user level.

		 */

		if (pfm_set_state(ctx_fd, 0, PFM_ST_STOP) == -1)

			fatal_error("pfm_set_state(stop) error errno %d\n",errno);

		/*

		 * read the results

		 */

		if (pfm_read(ctx_fd, 0, PFM_RW_PMD, pd, inp.pfp_event_count * sizeof(*pd)) == -1)

			fatal_error( "pfm_read error errno %d\n",errno);

		/*

		 * print the results

		 */

		puts("------------------------");

		for (i=0; i < inp.pfp_event_count; i++) {

			pfm_get_full_event_name(&inp.pfp_events[i], name, MAX_EVT_NAME_LEN);

			printf("CPU%-2d PMD%-3u raw=%-20"PRIu64" delta=%-20"PRIu64" %s\n",

					which_cpu,

					pd[i].reg_num,

					pd[i].reg_value,

					pd[i].reg_value - pdo[i],

					name);

			pdo[i] = pd[i].reg_value;

		}

	}

	/*

	 * destroy everything

	 */

	close(ctx_fd);

	return 0;

}