kern_usched.c

Version: - FREEBSD - FREEBSD-13-STABLE - FREEBSD-13-0 - FREEBSD-12-STABLE - FREEBSD-12-0 - FREEBSD-11-STABLE - FREEBSD-11-0 - FREEBSD-10-STABLE - FREEBSD-10-0 - FREEBSD-9-STABLE - FREEBSD-9-0 - FREEBSD-8-STABLE - FREEBSD-8-0 - FREEBSD-7-STABLE - FREEBSD-7-0 - FREEBSD-6-STABLE - FREEBSD-6-0 - FREEBSD-5-STABLE - FREEBSD-5-0 - FREEBSD-4-STABLE - FREEBSD-3-STABLE - FREEBSD22 - l41 - OPENBSD - linux-2.6 - MK84 - PLAN9 - xnu-8792
SearchContext: - none - 3 - 10
    1 /*
    2  * Copyright (c) 2005 The DragonFly Project.  All rights reserved.
    3  * 
    4  * This code is derived from software contributed to The DragonFly Project
    5  * by Sergey Glushchenko <deen@smz.com.ua>
    6  * 
    7  * Redistribution and use in source and binary forms, with or without
    8  * modification, are permitted provided that the following conditions
    9  * are met:
   10  * 
   11  * 1. Redistributions of source code must retain the above copyright
   12  *    notice, this list of conditions and the following disclaimer.
   13  * 2. Redistributions in binary form must reproduce the above copyright
   14  *    notice, this list of conditions and the following disclaimer in
   15  *    the documentation and/or other materials provided with the
   16  *    distribution.
   17  * 3. Neither the name of The DragonFly Project nor the names of its
   18  *    contributors may be used to endorse or promote products derived
   19  *    from this software without specific, prior written permission.
   20  * 
   21  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
   22  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
   23  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
   24  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
   25  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
   26  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
   27  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
   28  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
   29  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
   30  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
   31  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   32  * SUCH DAMAGE.
   33  * 
   34  * $DragonFly: src/sys/kern/kern_usched.c,v 1.9 2007/07/02 17:06:55 dillon Exp $
   35  */
   36 
   37 #include <sys/errno.h>
   38 #include <sys/globaldata.h>             /* curthread */
   39 #include <sys/proc.h>
   40 #include <sys/priv.h>
   41 #include <sys/sysproto.h>               /* struct usched_set_args */
   42 #include <sys/systm.h>                  /* strcmp() */
   43 #include <sys/usched.h> 
   44 
   45 #include <sys/mplock2.h>
   46 
   47 #include <machine/smp.h>
   48 
   49 static TAILQ_HEAD(, usched) usched_list = TAILQ_HEAD_INITIALIZER(usched_list);
   50 
   51 cpumask_t usched_mastermask = -1;
   52 
   53 /*
   54  * Called from very low level boot code, i386/i386/machdep.c/init386().
   55  * We cannot do anything fancy.  no malloc's, no nothing other then 
   56  * static initialization.
   57  */
   58 struct usched *
   59 usched_init(void)
   60 {
   61         const char *defsched;
   62 
   63         defsched = kgetenv("kern.user_scheduler");
   64 
   65         /*
   66          * Add various userland schedulers to the system.
   67          */
   68         usched_ctl(&usched_bsd4, USCH_ADD);
   69         usched_ctl(&usched_dfly, USCH_ADD);
   70         usched_ctl(&usched_dummy, USCH_ADD);
   71         if (defsched == NULL )
   72                 return(&usched_dfly);
   73         if (strcmp(defsched, "bsd4") == 0)
   74                 return(&usched_bsd4);
   75         if (strcmp(defsched, "dfly") == 0)
   76                 return(&usched_dfly);
   77         kprintf("WARNING: Running dummy userland scheduler\n");
   78         return(&usched_dummy);
   79 }
   80 
   81 /*
   82  * USCHED_CTL
   83  *
   84  * SYNOPSIS:
   85  *      Add/remove usched to/from list.
   86  *      
   87  * ARGUMENTS:
   88  *      usched - pointer to target scheduler
   89  *      action - addition or removal ?
   90  *
   91  * RETURN VALUES:
   92  *      0 - success
   93  *      EINVAL - error
   94  */
   95 int
   96 usched_ctl(struct usched *usched, int action)
   97 {
   98         struct usched *item;    /* temporaly for TAILQ processing */
   99         int error = 0;
  100 
  101         switch(action) {
  102         case USCH_ADD:
  103                 /*
  104                  * Make sure it isn't already on the list
  105                  */
  106 #ifdef INVARIANTS
  107                 TAILQ_FOREACH(item, &usched_list, entry) {
  108                         KKASSERT(item != usched);
  109                 }
  110 #endif
  111                 /*
  112                  * Optional callback to the scheduler before we officially
  113                  * add it to the list.
  114                  */
  115                 if (usched->usched_register)
  116                         usched->usched_register();
  117                 TAILQ_INSERT_TAIL(&usched_list, usched, entry);
  118                 break;
  119         case USCH_REM:
  120                 /*
  121                  * Do not allow the default scheduler to be removed
  122                  */
  123                 if (strcmp(usched->name, "bsd4") == 0) {
  124                         error = EINVAL;
  125                         break;
  126                 }
  127                 TAILQ_FOREACH(item, &usched_list, entry) {
  128                         if (item == usched)
  129                                 break;
  130                 }
  131                 if (item) {
  132                         if (item->usched_unregister)
  133                                 item->usched_unregister();
  134                         TAILQ_REMOVE(&usched_list, item, entry);
  135                 } else {
  136                         error = EINVAL;
  137                 }
  138                 break;
  139         default:
  140                 error = EINVAL;
  141                 break;
  142         }
  143         return (error);
  144 }
  145 
  146 /*
  147  * Called from the scheduler clock on each cpu independently at the
  148  * common scheduling rate.  If th scheduler clock interrupted a running
  149  * lwp the lp will be non-NULL.
  150  */
  151 void
  152 usched_schedulerclock(struct lwp *lp, sysclock_t periodic, sysclock_t time)
  153 {
  154         struct usched *item;
  155 
  156         TAILQ_FOREACH(item, &usched_list, entry) {
  157                 if (lp && lp->lwp_proc->p_usched == item)
  158                         item->schedulerclock(lp, periodic, time);
  159                 else
  160                         item->schedulerclock(NULL, periodic, time);
  161         }
  162 }
  163 
  164 /*
  165  * USCHED_SET(syscall)
  166  *
  167  * SYNOPSIS:
  168  *      Setting up a proc's usched.
  169  *
  170  * ARGUMENTS:
  171  *      pid     -
  172  *      cmd     -
  173  *      data    - 
  174  *      bytes   -
  175  * RETURN VALUES:
  176  *      0 - success
  177  *      EINVAL - error
  178  *
  179  * MPALMOSTSAFE
  180  */
  181 int
  182 sys_usched_set(struct usched_set_args *uap)
  183 {
  184         struct proc *p = curthread->td_proc;
  185         struct usched *item;    /* temporaly for TAILQ processing */
  186         int error;
  187         char buffer[NAME_LENGTH];
  188         cpumask_t mask;
  189         struct lwp *lp;
  190         int cpuid;
  191 
  192         if (uap->pid != 0 && uap->pid != curthread->td_proc->p_pid)
  193                 return (EINVAL);
  194 
  195         lp = curthread->td_lwp;
  196         get_mplock();
  197 
  198         switch (uap->cmd) {
  199         case USCHED_SET_SCHEDULER:
  200                 if ((error = priv_check(curthread, PRIV_SCHED_SET)) != 0)
  201                         break;
  202                 error = copyinstr(uap->data, buffer, sizeof(buffer), NULL);
  203                 if (error)
  204                         break;
  205                 TAILQ_FOREACH(item, &usched_list, entry) {
  206                         if ((strcmp(item->name, buffer) == 0))
  207                                 break;
  208                 }
  209 
  210                 /*
  211                  * If the scheduler for a process is being changed, disassociate
  212                  * the old scheduler before switching to the new one.  
  213                  *
  214                  * XXX we might have to add an additional ABI call to do a 'full
  215                  * disassociation' and another ABI call to do a 'full
  216                  * reassociation'
  217                  */
  218                 /* XXX lwp have to deal with multiple lwps here */
  219                 if (p->p_nthreads != 1) {
  220                         error = EINVAL;
  221                         break;
  222                 }
  223                 if (item && item != p->p_usched) {
  224                         /* XXX lwp */
  225                         p->p_usched->release_curproc(ONLY_LWP_IN_PROC(p));
  226                         p->p_usched->heuristic_exiting(ONLY_LWP_IN_PROC(p), p);
  227                         p->p_usched = item;
  228                 } else if (item == NULL) {
  229                         error = EINVAL;
  230                 }
  231                 break;
  232         case USCHED_SET_CPU:
  233                 if ((error = priv_check(curthread, PRIV_SCHED_CPUSET)) != 0)
  234                         break;
  235                 if (uap->bytes != sizeof(int)) {
  236                         error = EINVAL;
  237                         break;
  238                 }
  239                 error = copyin(uap->data, &cpuid, sizeof(int));
  240                 if (error)
  241                         break;
  242                 if (cpuid < 0 || cpuid >= ncpus) {
  243                         error = EFBIG;
  244                         break;
  245                 }
  246                 if ((smp_active_mask & CPUMASK(cpuid)) == 0) {
  247                         error = EINVAL;
  248                         break;
  249                 }
  250                 lp->lwp_cpumask = CPUMASK(cpuid);
  251                 if (cpuid != mycpu->gd_cpuid) {
  252                         lwkt_migratecpu(cpuid);
  253                         p->p_usched->changedcpu(lp);
  254                 }
  255                 break;
  256         case USCHED_GET_CPU:
  257                 /* USCHED_GET_CPU doesn't require special privileges. */
  258                 if (uap->bytes != sizeof(int)) {
  259                         error = EINVAL;
  260                         break;
  261                 }
  262                 error = copyout(&(mycpu->gd_cpuid), uap->data, sizeof(int));
  263                 break;
  264         case USCHED_ADD_CPU:
  265                 if ((error = priv_check(curthread, PRIV_SCHED_CPUSET)) != 0)
  266                         break;
  267                 if (uap->bytes != sizeof(int)) {
  268                         error = EINVAL;
  269                         break;
  270                 }
  271                 error = copyin(uap->data, &cpuid, sizeof(int));
  272                 if (error)
  273                         break;
  274                 if (cpuid < 0 || cpuid >= ncpus) {
  275                         error = EFBIG;
  276                         break;
  277                 }
  278                 if (!(smp_active_mask & CPUMASK(cpuid))) {
  279                         error = EINVAL;
  280                         break;
  281                 }
  282                 lp->lwp_cpumask |= CPUMASK(cpuid);
  283                 break;
  284         case USCHED_DEL_CPU:
  285                 /* USCHED_DEL_CPU doesn't require special privileges. */
  286                 if (uap->bytes != sizeof(int)) {
  287                         error = EINVAL;
  288                         break;
  289                 }
  290                 error = copyin(uap->data, &cpuid, sizeof(int));
  291                 if (error)
  292                         break;
  293                 if (cpuid < 0 || cpuid >= ncpus) {
  294                         error = EFBIG;
  295                         break;
  296                 }
  297                 lp = curthread->td_lwp;
  298                 mask = lp->lwp_cpumask & smp_active_mask & ~CPUMASK(cpuid);
  299                 if (mask == 0)
  300                         error = EPERM;
  301                 else {
  302                         lp->lwp_cpumask &= ~CPUMASK(cpuid);
  303                         if ((lp->lwp_cpumask & mycpu->gd_cpumask) == 0) {
  304                                 cpuid = BSFCPUMASK(lp->lwp_cpumask &
  305                                                    smp_active_mask);
  306                                 lwkt_migratecpu(cpuid);
  307                                 p->p_usched->changedcpu(lp);
  308                         }
  309                 }
  310                 break;
  311         default:
  312                 error = EINVAL;
  313                 break;
  314         }
  315         rel_mplock();
  316         return (error);
  317 }
  318
Cache object: 2d995eab8ab1798a37ef657e92be3de0
[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]
This page is part of the FreeBSD/Linux Linux Kernel Cross-Reference, and was automatically generated using a modified version of the LXR engine.
FreeBSD/Linux Kernel Cross Reference sys/kern/kern_usched.c

FreeBSD/Linux Kernel Cross Reference
sys/kern/kern_usched.c
