src/lib/cpu.c

/*
 * Copyright (C) 2000-2005 SWsoft. All rights reserved.
 *
 * This file may be distributed under the terms of the Q Public License
 * as defined by Trolltech AS of Norway and appearing in the file
 * LICENSE.QPL included in the packaging of this file.
 *
 * This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
 * WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 */

#include <stdlib.h>
#include <unistd.h>
#include <sys/syscall.h>
#include <asm/timex.h>
#include <linux/vzcalluser.h>
#include <errno.h>

#include "types.h"
#include "cpu.h"
#include "env.h"
#include "vzerror.h"
#include "logger.h"

#ifndef __NR_fairsched_chwt
#ifdef __ia64__
#define __NR_fairsched_chwt    1502
#else
#define __NR_fairsched_chwt    502
#endif
#endif
#ifndef __NR_fairsched_rate
#ifdef __ia64__
#define __NR_fairsched_rate    1504
#else
#define __NR_fairsched_rate    504
#endif
#endif

static inline int fairsched_chwt(unsigned int id, unsigned wght)
{
	int ret;

	ret = syscall(__NR_fairsched_chwt, id, wght);
	if (ret && errno == ENOSYS)
		ret = 0;
	return ret;
}

static inline int fairsched_rate(unsigned int id, int op, unsigned rate)
{
	int ret;

	ret = syscall(__NR_fairsched_rate, id, op, rate);
	if (ret && errno == ENOSYS)
		ret = 0;
	return ret;
}

static int set_cpulimit(envid_t veid, unsigned int cpulimit)
{
	unsigned cpulim1024 = (float)cpulimit * 1024 / 100;

	if (fairsched_rate(veid, cpulim1024 ? 0 : 1, cpulim1024) < 0) {
		logger(0, errno, "fairsched_rate");
		return VZ_SETFSHD_ERROR;
	}
	return 0;
}

static int set_cpuweight(envid_t veid, unsigned int cpuweight)
{

	if (fairsched_chwt(veid, cpuweight)) {
		logger(0, errno, "fairsched_chwt");
		return VZ_SETFSHD_ERROR;
	}
	return 0;
}

static int set_cpuunits(envid_t veid, unsigned int cpuunits)
{
	int cpuweight, ret;

	if (cpuunits < MINCPUUNITS || cpuunits > MAXCPUUNITS) {
		logger(0, 0, "Invalid value for cpuunit: %d"
			" allowed range is %d-%d",
			cpuunits, MINCPUUNITS, MAXCPUUNITS);
		return VZ_SETFSHD_ERROR;
	}
	cpuweight = MAXCPUUNITS / cpuunits;
	ret = set_cpuweight(veid, cpuweight);
	return ret;
}

/**  Apply cpu parameters on Host system.
 *
 * @param cpu		cpu parameters.
 * @return		0 on success.
 */
int hn_set_cpu(cpu_param *cpu)
{
	if (cpu->units == NULL)
		return 0;
	return set_cpuunits(2147483647, *cpu->units);
}

/**  Apply cpu parameters on running VPS.
 *
 * @param h		VPS handler.
 * @param veid		VPS id.
 * @param cpu		cpu parameters.
 * @return		0 on success.
 */
int vps_set_cpu(vps_handler *h, envid_t veid, cpu_param *cpu)
{
	int ret = 0;

	if (cpu->limit == NULL &&
		cpu->units == NULL &&
		cpu->weight == NULL)
	{
		return 0;
	}
	if (!vps_is_run(h, veid)) {
		logger(0, 0, "Unable to apply CPU parameters: VPS is not"
			" running");
		return VZ_VE_NOT_RUNNING;
	}
	if (cpu->limit != NULL) {
		logger(0, 0, "Setting CPU limit: %d", cpu->limit[0]);
		ret = set_cpulimit(veid, *cpu->limit);
	}
	if (cpu->units != NULL) {
		logger(0, 0, "Setting CPU units: %d", cpu->units[0]);
		ret = set_cpuunits(veid, *cpu->units);
	} else if (cpu->weight != NULL)
		ret = set_cpuweight(veid, *cpu->weight);

	return ret;
}