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/*
* Copyright © 2013 Intel Corporation
*
* 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 (including the next
* paragraph) 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 <stdio.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
#include "cpu-top.h"
int cpu_top_update(struct cpu_top *cpu)
{
struct cpu_stat *s = &cpu->stat[cpu->count++&1];
struct cpu_stat *d = &cpu->stat[cpu->count&1];
uint64_t d_total, d_idle;
char buf[4096];
int fd, len = -1;
fd = open("/proc/stat", 0);
if (fd < 0)
return errno;
len = read(fd, buf, sizeof(buf)-1);
close(fd);
if (len < 0)
return EIO;
buf[len] = '\0';
#ifdef __x86_64__
sscanf(buf, "cpu %lu %lu %lu %lu",
&s->user, &s->nice, &s->sys, &s->idle);
#else
sscanf(buf, "cpu %llu %llu %llu %llu",
&s->user, &s->nice, &s->sys, &s->idle);
#endif
s->total = s->user + s->nice + s->sys + s->idle;
if (cpu->count == 1)
return EAGAIN;
d_total = s->total - d->total;
d_idle = s->idle - d->idle;
cpu->busy = 100 - 100 * d_idle / d_total;
return 0;
}
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