char netcpu_procstat_id[]="\
@(#)netcpu_procstat.c (c) Copyright 2005-2012 Version 2.6.0";
/* netcpu_procstat.c
Implement the /proc/stat specific portions of netperf CPU
utilization measurements. These are broken-out into a separate file
to make life much nicer over in netlib.c which had become a maze of
twisty, CPU-util-related, #ifdefs, all different. raj 2005-01-26
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include <stdio.h>
#ifdef HAVE_FCNTL_H
# include <fcntl.h>
#endif
#if HAVE_UNISTD_H
# include <unistd.h>
#endif
#if STDC_HEADERS
# include <stdlib.h>
# include <stddef.h>
#else
# if HAVE_STDLIB_H
# include <stdlib.h>
# endif
#endif
#include <string.h>
#include "netsh.h"
#include "netlib.h"
/* the lib_start_count and lib_end_count arrays hold the starting
and ending values of whatever is counting when the system is
idle. The rate at which this increments during a test is compared
with a previous calibrarion to arrive at a CPU utilization
percentage. raj 2005-01-26 */
#define IDLE_IDX 4
#define CPU_STATES 10
typedef struct cpu_states
{
uint64_t user;
uint64_t nice;
uint64_t sys;
uint64_t idle;
uint64_t iowait;
uint64_t hard_irq;
uint64_t soft_irq;
uint64_t steal;
uint64_t guest;
uint64_t guest_nice;
} cpu_states_t;
static cpu_states_t lib_start_count[MAXCPUS];
static cpu_states_t lib_end_count[MAXCPUS];
/* The max. length of one line of /proc/stat cpu output */
#define CPU_LINE_LENGTH (int)((CPU_STATES * sizeof (long) / 3 + 1) * 4 + 8)
#define PROC_STAT_FILE_NAME "/proc/stat"
#define N_CPU_LINES(nr) (nr == 1 ? 1 : 1 + nr)
static int proc_stat_fd = -1;
static char *proc_stat_buf = NULL;
static int proc_stat_buflen = 0;
void
cpu_util_init(void)
{
if (debug) {
fprintf(where,
"cpu_util_init enter, proc_stat_fd %d proc_stat_buf %p\n",
proc_stat_fd,
proc_stat_buf);
fflush(where);
}
if (proc_stat_fd < 0) {
proc_stat_fd = open (PROC_STAT_FILE_NAME, O_RDONLY, NULL);
if (proc_stat_fd < 0) {
fprintf (stderr, "Cannot open %s!\n", PROC_STAT_FILE_NAME);
exit (1);
};
};
if (!proc_stat_buf) {
proc_stat_buflen = N_CPU_LINES (lib_num_loc_cpus) * CPU_LINE_LENGTH;
if (debug) {
fprintf(where,
"lib_num_loc_cpus %d lines %d CPU_LINE_LENGTH %d proc_stat_buflen %d\n",
lib_num_loc_cpus,
N_CPU_LINES(lib_num_loc_cpus),
CPU_LINE_LENGTH,
proc_stat_buflen);
fflush(where);
}
proc_stat_buf = (char *)malloc (proc_stat_buflen);
if (!proc_stat_buf) {
fprintf (stderr, "Cannot allocate buffer memory!\n");
exit (1);
}
}
return;
}
void
cpu_util_terminate(void)
{
close(proc_stat_fd);
proc_stat_fd = -1;
free(proc_stat_buf);
proc_stat_buf = NULL;
return;
}
int
get_cpu_method()
{
return PROC_STAT;
}
float
calibrate_idle_rate (int iterations, int interval)
{
if (proc_stat_fd < 0) {
proc_stat_fd = open (PROC_STAT_FILE_NAME, O_RDONLY, NULL);
if (proc_stat_fd < 0) {
fprintf (stderr, "Cannot open %s!\n", PROC_STAT_FILE_NAME);
exit (1);
};
};
if (!proc_stat_buf) {
proc_stat_buflen = N_CPU_LINES (lib_num_loc_cpus) * CPU_LINE_LENGTH;
if (debug) {
fprintf(where,
"calibrate: lib_num_loc_cpus %d lines %d CPU_LINE_LENGTH %d proc_stat_buflen %d\n",
lib_num_loc_cpus,
N_CPU_LINES(lib_num_loc_cpus),
CPU_LINE_LENGTH,
proc_stat_buflen);
fflush(where);
}
proc_stat_buf = (char *)malloc (proc_stat_buflen);
if (!proc_stat_buf) {
fprintf (stderr, "Cannot allocate buffer memory!\n");
exit (1);
};
};
return sysconf (_SC_CLK_TCK);
}
static void
get_cpu (cpu_states_t *res)
{
int i;
int n = lib_num_loc_cpus;
char *p = proc_stat_buf;
lseek (proc_stat_fd, 0, SEEK_SET);
read (proc_stat_fd, p, proc_stat_buflen);
if (debug) {
fprintf(where,"proc_stat_buf '%.*s'\n",proc_stat_buflen,p);
fflush(where);
}
/* Skip first line (total) on SMP */
if (n > 1) p = strchr (p, '\n');
for (i = 0; i < n; i++) {
memset(&res[i], 0, sizeof (res[i]));
p = strchr (p, ' ');
sscanf(p, "%llu %llu %llu %llu %llu %llu %llu %llu %llu %llu",
(unsigned long long *)&res[i].user,
(unsigned long long *)&res[i].nice,
(unsigned long long *)&res[i].sys,
(unsigned long long *)&res[i].idle,
(unsigned long long *)&res[i].iowait,
(unsigned long long *)&res[i].hard_irq,
(unsigned long long *)&res[i].soft_irq,
(unsigned long long *)&res[i].steal,
(unsigned long long *)&res[i].guest,
(unsigned long long *)&res[i].guest_nice);
if (debug) {
fprintf(where,
"res[%d] is %llu %llu %llu %llu %llu %llu %llu %llu %llu %llu\n",
i,
(unsigned long long)res[i].user,
(unsigned long long)res[i].nice,
(unsigned long long)res[i].sys,
(unsigned long long)res[i].idle,
(unsigned long long)res[i].iowait,
(unsigned long long)res[i].hard_irq,
(unsigned long long)res[i].soft_irq,
(unsigned long long)res[i].steal,
(unsigned long long)res[i].guest,
(unsigned long long)res[i].guest_nice);
fflush(where);
}
p = strchr (p, '\n');
};
}
/* take the initial timestamp and start collecting CPU utilization if
requested */
void
measure_cpu_start()
{
cpu_method = PROC_STAT;
get_cpu(lib_start_count);
}
/* collect final CPU utilization raw data */
void
measure_cpu_stop()
{
get_cpu(lib_end_count);
}
static uint64_t
tick_subtract(uint64_t start, uint64_t end)
{
if (end >= start || (start & 0xffffffff00000000ULL))
return (end - start);
/*
* We wrapped, and it is likely that the kernel is suppling 32-bit
* counters, because "start" is less than 32-bits wide. If that's
* the case, then handle the wrap by subtracting off everything but
* the lower 32-bits so as to get back to unsigned 32-bit
* arithmetic.
*/
return (end - start + 0xffffffff00000000ULL);
}
float
calc_cpu_util_internal(float elapsed_time)
{
int i;
float correction_factor;
cpu_states_t diff;
uint64_t total_ticks;
memset(&lib_local_cpu_stats, 0, sizeof(lib_local_cpu_stats));
/* It is possible that the library measured a time other than the
one that the user want for the cpu utilization calculations - for
example, tests that were ended by watchdog timers such as the udp
stream test. We let these tests tell up what the elapsed time
should be. */
if (elapsed_time != 0.0) {
correction_factor = (float) 1.0 +
((lib_elapsed - elapsed_time) / elapsed_time);
}
else {
correction_factor = (float) 1.0;
}
if (debug) {
fprintf(where,
"lib_local_maxrate = %f\n", lib_local_maxrate);
}
for (i = 0; i < lib_num_loc_cpus; i++) {
/* Find the difference in all CPU stat fields */
diff.user =
tick_subtract(lib_start_count[i].user, lib_end_count[i].user);
diff.nice =
tick_subtract(lib_start_count[i].nice, lib_end_count[i].nice);
diff.sys =
tick_subtract(lib_start_count[i].sys, lib_end_count[i].sys);
diff.idle =
tick_subtract(lib_start_count[i].idle, lib_end_count[i].idle);
diff.iowait =
tick_subtract(lib_start_count[i].iowait, lib_end_count[i].iowait);
diff.hard_irq =
tick_subtract(lib_start_count[i].hard_irq, lib_end_count[i].hard_irq);
diff.soft_irq =
tick_subtract(lib_start_count[i].soft_irq, lib_end_count[i].soft_irq);
diff.steal =
tick_subtract(lib_start_count[i].steal, lib_end_count[i].steal);
diff.guest =
tick_subtract(lib_start_count[i].guest, lib_end_count[i].guest);
diff.guest_nice =
tick_subtract(lib_start_count[i].guest_nice, lib_end_count[i].guest_nice);
total_ticks = diff.user + diff.nice + diff.sys + diff.idle + diff.iowait
+ diff.hard_irq + diff.soft_irq + diff.steal
+ diff.guest + diff.guest_nice;
/* calculate idle time as a percentage of all CPU states */
if (total_ticks == 0) {
if (debug) {
fprintf(where, "Total ticks 0 on CPU %d, charging nothing!\n", i);
}
lib_local_per_cpu_util[i] = 0.0;
} else {
#define CPU_STAT_PERCENTIZE(x) (100. * (((float)(x)) / ((float)(total_ticks))))
/* utilization = 100% - %idle */
lib_local_per_cpu_util[i] = 100. - CPU_STAT_PERCENTIZE(diff.idle);
lib_local_cpu_stats.cpu_util += lib_local_per_cpu_util[i];
lib_local_cpu_stats.cpu_user += CPU_STAT_PERCENTIZE(diff.user);
lib_local_cpu_stats.cpu_system += CPU_STAT_PERCENTIZE(diff.sys);
lib_local_cpu_stats.cpu_iowait += CPU_STAT_PERCENTIZE(diff.iowait);
lib_local_cpu_stats.cpu_irq += CPU_STAT_PERCENTIZE(diff.hard_irq);
lib_local_cpu_stats.cpu_swintr += CPU_STAT_PERCENTIZE(diff.soft_irq);
}
/* apply correction factor */
lib_local_per_cpu_util[i] *= correction_factor;
if (debug) {
fprintf(where,
"calc_cpu_util: util on processor %d, diff = %llu %llu %llu "
"%llu %llu %llu %llu %llu %llu util %f cf %f\n",
i,
(unsigned long long)diff.user,
(unsigned long long)diff.nice,
(unsigned long long)diff.sys,
(unsigned long long)diff.idle,
(unsigned long long)diff.iowait,
(unsigned long long)diff.hard_irq,
(unsigned long long)diff.soft_irq,
(unsigned long long)diff.steal,
(unsigned long long)diff.guest,
lib_local_per_cpu_util[i],
correction_factor);
}
}
/* we want to apply correction factor and average across all n processors */
#define CPU_STAT_FIXUP(fldname) \
lib_local_cpu_stats.fldname = ((correction_factor \
* lib_local_cpu_stats.fldname) \
/ ((float)lib_num_loc_cpus))
CPU_STAT_FIXUP(cpu_util);
CPU_STAT_FIXUP(cpu_user);
CPU_STAT_FIXUP(cpu_system);
CPU_STAT_FIXUP(cpu_iowait);
CPU_STAT_FIXUP(cpu_irq);
CPU_STAT_FIXUP(cpu_swintr);
return lib_local_cpu_stats.cpu_util;
}
void
cpu_start_internal(void)
{
get_cpu(lib_start_count);
return;
}
void
cpu_stop_internal(void)
{
get_cpu(lib_end_count);
}