source: trunk/kernel/syscalls/sys_thread_migrate.c @ 81

/*
 * kern/sys_thread_migrate.c - calls the scheduler to yield current CPU
 * 
 * Copyright (c) 2008,2009,2010,2011,2012 Ghassan Almaless
 * Copyright (c) 2011,2012 UPMC Sorbonne Universites
 *
 * This file is part of ALMOS-kernel.
 *
 * ALMOS-kernel is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by
 * the Free Software Foundation; version 2.0 of the License.
 *
 * ALMOS-kernel is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with ALMOS-kernel; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
 */

#include <cpu.h>
#include <thread.h>
#include <task.h>
#include <scheduler.h>

#define MAX_CPU_NR (CONFIG_MAX_CLUSTER_NR * CONFIG_MAX_CPU_PER_CLUSTER_NR)

int sys_thread_migrate(pthread_attr_t *thread_attr)
{
        struct thread_s *this;
        pthread_attr_t attr;
        uint_t mode;
        sint_t cpu_gid;
        error_t err;

        this = current_thread;

        if(thread_attr == NULL)
        {
                err = EINVAL;
                goto fail_inval;
        }

        if(NOT_IN_USPACE((uint_t)thread_attr))
        {
                err = EPERM;
                goto fail_access;
        }

        if((err = cpu_copy_from_uspace(&attr, thread_attr, sizeof(attr))))
                goto fail_ucopy_attr;

        cpu_gid = (sint_t)cpu_get_id();

        if(attr.cpu_gid == cpu_gid)
        {
                thread_migration_disable(this);
                return 0;
        }

        if((attr.cpu_gid > 0) && (attr.cpu_gid >= MAX_CPU_NR))
        {
                err = EINVAL;
                goto fail_attr_inval;
        }

        cpu_gid = (attr.cpu_gid < 0) ? -1 : (attr.cpu_gid % arch_onln_cpu_nr());

        if(attr.flags & PT_ATTR_AUTO_MGRT)
                this->info.attr.flags |= PT_ATTR_AUTO_MGRT;

#if CONFIG_SHOW_SYSMGRT_MSG
        printk(INFO, "INFO: %s: pid %d, tid %d (%x), cpu %d: asked to migrate to cpu %d [%u]\n",
               __FUNCTION__,
               this->task->pid,
               this->info.order,
               this,
               cpu_get_id(),
               cpu_gid,
               cpu_time_stamp());
#endif

        cpu_disable_all_irq(&mode);
        thread_clear_cap_migrate(this);
        cpu_restore_irq(mode);

        err = thread_migrate(this, cpu_gid);

        /* Reload this pointer */
        this = current_thread;

        cpu_disable_all_irq(&mode);
        thread_set_cap_migrate(this);
        thread_migration_deactivate(this);
        cpu_restore_irq(mode);

#if CONFIG_SHOW_SYSMGRT_MSG
        printk(INFO, "INFO: %s: pid %d, tid %d (%x), cpu %d, err %d, done [%u]\n", 
               __FUNCTION__,
               this->task->pid,
               this->info.order,
               current_thread,
               cpu_get_id(),
               err,
               cpu_time_stamp());
#endif

fail_attr_inval:
fail_ucopy_attr:
fail_access:
fail_inval:
        this->info.errno = err;
        return (err) ? -1 : 0;
}