sys_pset.c revision 1.1
1 /* $NetBSD: sys_pset.c,v 1.1 2008/01/15 03:41:49 rmind Exp $ */ 2 3 /* 4 * Copyright (c) 2008, Mindaugas Rasiukevicius <rmind at NetBSD org> 5 * All rights reserved. 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 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 17 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 18 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 19 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 20 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 21 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 22 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 23 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 24 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 25 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 26 * POSSIBILITY OF SUCH DAMAGE. 27 */ 28 29 /* 30 * Implementation of the Processor Sets. 31 * 32 * Locking 33 * The array of the processor-set structures and its members are protected 34 * by the global psets_lock. Note that in scheduler, the very l_psid value 35 * might be used without lock held. 36 */ 37 38 #include <sys/cdefs.h> 39 __KERNEL_RCSID(0, "$NetBSD: sys_pset.c,v 1.1 2008/01/15 03:41:49 rmind Exp $"); 40 41 #include <sys/param.h> 42 43 #include <sys/cpu.h> 44 #include <sys/kauth.h> 45 #include <sys/kmem.h> 46 #include <sys/lwp.h> 47 #include <sys/mutex.h> 48 #include <sys/proc.h> 49 #include <sys/pset.h> 50 #include <sys/sched.h> 51 #include <sys/syscallargs.h> 52 #include <sys/sysctl.h> 53 #include <sys/systm.h> 54 #include <sys/types.h> 55 56 static pset_info_t ** psets; 57 static kmutex_t psets_lock; 58 static u_int psets_max; 59 static u_int psets_count; 60 61 static int psets_realloc(int); 62 static int psid_validate(psetid_t, bool); 63 static int kern_pset_create(psetid_t *); 64 static int kern_pset_destroy(psetid_t); 65 66 /* 67 * Initialization of the processor-sets. 68 */ 69 void 70 psets_init(void) 71 { 72 73 psets_max = max(MAXCPUS, 32); 74 psets = kmem_zalloc(psets_max * sizeof(void *), KM_SLEEP); 75 mutex_init(&psets_lock, MUTEX_DEFAULT, IPL_NONE); 76 psets_count = 0; 77 } 78 79 /* 80 * Reallocate the array of the processor-set structures. 81 */ 82 static int 83 psets_realloc(int new_psets_max) 84 { 85 pset_info_t **new_psets, **old_psets; 86 const u_int newsize = new_psets_max * sizeof(void *); 87 u_int i, oldsize; 88 89 if (new_psets_max < 1) 90 return EINVAL; 91 92 new_psets = kmem_zalloc(newsize, KM_SLEEP); 93 mutex_enter(&psets_lock); 94 old_psets = psets; 95 oldsize = psets_max * sizeof(void *); 96 97 /* Check if we can lower the size of the array */ 98 if (new_psets_max < psets_max) { 99 for (i = new_psets_max; i < psets_max; i++) { 100 if (psets[i] == NULL) 101 continue; 102 mutex_exit(&psets_lock); 103 kmem_free(new_psets, newsize); 104 return EBUSY; 105 } 106 } 107 108 /* Copy all pointers to the new array */ 109 memcpy(new_psets, psets, newsize); 110 psets_max = new_psets_max; 111 psets = new_psets; 112 mutex_exit(&psets_lock); 113 114 kmem_free(old_psets, oldsize); 115 return 0; 116 } 117 118 /* 119 * Validate processor-set ID. 120 */ 121 static int 122 psid_validate(psetid_t psid, bool chkps) 123 { 124 125 KASSERT(mutex_owned(&psets_lock)); 126 127 if (chkps && (psid == PS_NONE || psid == PS_QUERY || psid == PS_MYID)) 128 return 0; 129 if (psid <= 0 || psid > psets_max) 130 return EINVAL; 131 if (psets[psid - 1] == NULL) 132 return EINVAL; 133 if (psets[psid - 1]->ps_flags & PSET_BUSY) 134 return EBUSY; 135 136 return 0; 137 } 138 139 /* 140 * Create a processor-set. 141 */ 142 static int 143 kern_pset_create(psetid_t *psid) 144 { 145 pset_info_t *pi; 146 u_int i; 147 148 if (psets_count == psets_max) 149 return ENOMEM; 150 151 pi = kmem_zalloc(sizeof(pset_info_t), KM_SLEEP); 152 153 mutex_enter(&psets_lock); 154 if (psets_count == psets_max) { 155 mutex_exit(&psets_lock); 156 kmem_free(pi, sizeof(pset_info_t)); 157 return ENOMEM; 158 } 159 160 /* Find a free entry in the array */ 161 for (i = 0; i < psets_max; i++) 162 if (psets[i] == NULL) 163 break; 164 KASSERT(i != psets_max); 165 166 psets[i] = pi; 167 psets_count++; 168 mutex_exit(&psets_lock); 169 170 *psid = i + 1; 171 return 0; 172 } 173 174 /* 175 * Destroy a processor-set. 176 */ 177 static int 178 kern_pset_destroy(psetid_t psid) 179 { 180 struct cpu_info *ci; 181 pset_info_t *pi; 182 struct lwp *l; 183 CPU_INFO_ITERATOR cii; 184 int error; 185 186 mutex_enter(&psets_lock); 187 if (psid == PS_MYID) { 188 /* Use caller's processor-set ID */ 189 psid = curlwp->l_psid; 190 } 191 error = psid_validate(psid, false); 192 if (error) { 193 mutex_exit(&psets_lock); 194 return error; 195 } 196 197 /* Release the processor-set from all CPUs */ 198 for (CPU_INFO_FOREACH(cii, ci)) { 199 struct schedstate_percpu *spc; 200 201 spc = &ci->ci_schedstate; 202 if (spc->spc_psid != psid) 203 continue; 204 spc->spc_psid = PS_NONE; 205 } 206 /* Mark that processor-set is going to be destroyed */ 207 pi = psets[psid - 1]; 208 pi->ps_flags |= PSET_BUSY; 209 mutex_exit(&psets_lock); 210 211 /* Unmark the processor-set ID from each thread */ 212 mutex_enter(&proclist_lock); 213 LIST_FOREACH(l, &alllwp, l_list) { 214 /* Safe to check and set without lock held */ 215 if (l->l_psid != psid) 216 continue; 217 l->l_psid = PS_NONE; 218 } 219 mutex_exit(&proclist_lock); 220 221 /* Destroy the processor-set */ 222 mutex_enter(&psets_lock); 223 psets[psid - 1] = NULL; 224 psets_count--; 225 mutex_exit(&psets_lock); 226 227 kmem_free(pi, sizeof(pset_info_t)); 228 return 0; 229 } 230 231 /* 232 * General system calls for the processor-sets. 233 */ 234 235 int 236 sys_pset_create(struct lwp *l, const struct sys_pset_create_args *uap, 237 register_t *retval) 238 { 239 /* { 240 syscallarg(psetid_t) *psid; 241 } */ 242 psetid_t psid; 243 int error; 244 245 /* Available only for super-user */ 246 if (kauth_authorize_generic(l->l_cred, KAUTH_GENERIC_ISSUSER, NULL)) 247 return EPERM; 248 249 error = kern_pset_create(&psid); 250 if (error) 251 return error; 252 253 error = copyout(&psid, SCARG(uap, psid), sizeof(psetid_t)); 254 if (error) 255 (void)kern_pset_destroy(psid); 256 257 return error; 258 } 259 260 int 261 sys_pset_destroy(struct lwp *l, const struct sys_pset_destroy_args *uap, 262 register_t *retval) 263 { 264 /* { 265 syscallarg(psetid_t) psid; 266 } */ 267 268 /* Available only for super-user */ 269 if (kauth_authorize_generic(l->l_cred, KAUTH_GENERIC_ISSUSER, NULL)) 270 return EPERM; 271 272 return kern_pset_destroy(SCARG(uap, psid)); 273 } 274 275 int 276 sys_pset_assign(struct lwp *l, const struct sys_pset_assign_args *uap, 277 register_t *retval) 278 { 279 /* { 280 syscallarg(psetid_t) psid; 281 syscallarg(cpuid_t) cpuid; 282 syscallarg(psetid_t) *opsid; 283 } */ 284 struct cpu_info *ci; 285 struct schedstate_percpu *spc; 286 psetid_t psid = SCARG(uap, psid), opsid = 0; 287 CPU_INFO_ITERATOR cii; 288 int error = 0; 289 290 /* Available only for super-user, except the case of PS_QUERY */ 291 if (kauth_authorize_generic(l->l_cred, KAUTH_GENERIC_ISSUSER, NULL) && 292 psid != PS_QUERY) 293 return EPERM; 294 295 /* Find the target CPU */ 296 for (CPU_INFO_FOREACH(cii, ci)) 297 if (cpu_index(ci) == SCARG(uap, cpuid)) 298 break; 299 if (ci == NULL) 300 return EINVAL; 301 spc = &ci->ci_schedstate; 302 303 mutex_enter(&psets_lock); 304 error = psid_validate(psid, true); 305 if (error) { 306 mutex_exit(&psets_lock); 307 return error; 308 } 309 opsid = spc->spc_psid; 310 switch (psid) { 311 case PS_QUERY: 312 break; 313 case PS_MYID: 314 psid = curlwp->l_psid; 315 default: 316 spc->spc_psid = psid; 317 } 318 mutex_exit(&psets_lock); 319 320 if (SCARG(uap, opsid) != NULL) 321 error = copyout(&opsid, SCARG(uap, opsid), sizeof(psetid_t)); 322 323 return error; 324 } 325 326 int 327 sys__pset_bind(struct lwp *l, const struct sys__pset_bind_args *uap, 328 register_t *retval) 329 { 330 /* { 331 syscallarg(idtype_t) idtype; 332 syscallarg(id_t) first_id; 333 syscallarg(id_t) second_id; 334 syscallarg(psetid_t) psid; 335 syscallarg(psetid_t) *opsid; 336 } */ 337 struct cpu_info *ci; 338 struct proc *p; 339 struct lwp *t; 340 id_t id1, id2; 341 pid_t pid = 0; 342 lwpid_t lid = 0; 343 psetid_t psid, opsid; 344 int error = 0, lcnt; 345 346 psid = SCARG(uap, psid); 347 348 /* Available only for super-user, except the case of PS_QUERY */ 349 if (kauth_authorize_generic(l->l_cred, KAUTH_GENERIC_ISSUSER, NULL) && 350 psid != PS_QUERY) 351 return EPERM; 352 353 mutex_enter(&psets_lock); 354 error = psid_validate(psid, true); 355 if (error) { 356 mutex_exit(&psets_lock); 357 return error; 358 } 359 if (psid == PS_MYID) 360 psid = curlwp->l_psid; 361 if (psid != PS_QUERY && psid != PS_NONE) 362 psets[psid - 1]->ps_flags |= PSET_BUSY; 363 mutex_exit(&psets_lock); 364 365 /* 366 * Get PID and LID from the ID. 367 */ 368 p = l->l_proc; 369 id1 = SCARG(uap, first_id); 370 id2 = SCARG(uap, second_id); 371 372 switch (SCARG(uap, idtype)) { 373 case P_PID: 374 /* 375 * Process: 376 * First ID - PID; 377 * Second ID - ignored; 378 */ 379 pid = (id1 == P_MYID) ? p->p_pid : id1; 380 lid = 0; 381 break; 382 case P_LWPID: 383 /* 384 * Thread (LWP): 385 * First ID - LID; 386 * Second ID - PID; 387 */ 388 if (id1 == P_MYID) { 389 pid = p->p_pid; 390 lid = l->l_lid; 391 break; 392 } 393 lid = id1; 394 pid = (id2 == P_MYID) ? p->p_pid : id2; 395 break; 396 default: 397 return EINVAL; 398 } 399 400 /* Find the process */ 401 p = p_find(pid, PFIND_UNLOCK_FAIL); 402 if (p == NULL) { 403 error = ESRCH; 404 goto error; 405 } 406 mutex_enter(&p->p_smutex); 407 mutex_exit(&proclist_lock); 408 409 /* Disallow modification of the system processes */ 410 if (p->p_flag & PK_SYSTEM) { 411 mutex_exit(&p->p_smutex); 412 error = EPERM; 413 goto error; 414 } 415 416 /* Find the LWP(s) */ 417 lcnt = 0; 418 ci = NULL; 419 LIST_FOREACH(t, &p->p_lwps, l_sibling) { 420 if (lid && lid != t->l_lid) 421 continue; 422 /* 423 * Bind the thread to the processor-set, 424 * take some CPU and migrate. 425 */ 426 lwp_lock(t); 427 opsid = t->l_psid; 428 t->l_psid = psid; 429 ci = sched_takecpu(l); 430 /* Unlocks LWP */ 431 lwp_migrate(t, ci); 432 lcnt++; 433 } 434 mutex_exit(&p->p_smutex); 435 if (lcnt == 0) { 436 error = ESRCH; 437 goto error; 438 } 439 *retval = lcnt; 440 if (SCARG(uap, opsid)) 441 error = copyout(&opsid, SCARG(uap, opsid), sizeof(psetid_t)); 442 error: 443 if (psid != PS_QUERY && psid != PS_NONE) { 444 mutex_enter(&psets_lock); 445 psets[psid - 1]->ps_flags &= ~PSET_BUSY; 446 mutex_exit(&psets_lock); 447 } 448 return error; 449 } 450 451 /* 452 * Sysctl nodes and initialization. 453 */ 454 455 static int 456 sysctl_psets_max(SYSCTLFN_ARGS) 457 { 458 struct sysctlnode node; 459 int error, newsize; 460 461 node = *rnode; 462 node.sysctl_data = &newsize; 463 464 newsize = psets_max; 465 error = sysctl_lookup(SYSCTLFN_CALL(&node)); 466 if (error || newp == NULL) 467 return error; 468 469 if (newsize <= 0) 470 return EINVAL; 471 472 sysctl_unlock(); 473 error = psets_realloc(newsize); 474 sysctl_relock(); 475 return error; 476 } 477 478 SYSCTL_SETUP(sysctl_pset_setup, "sysctl kern.pset subtree setup") 479 { 480 const struct sysctlnode *node = NULL; 481 482 sysctl_createv(clog, 0, NULL, NULL, 483 CTLFLAG_PERMANENT, 484 CTLTYPE_NODE, "kern", NULL, 485 NULL, 0, NULL, 0, 486 CTL_KERN, CTL_EOL); 487 sysctl_createv(clog, 0, NULL, &node, 488 CTLFLAG_PERMANENT, 489 CTLTYPE_NODE, "pset", 490 SYSCTL_DESCR("Processor-set options"), 491 NULL, 0, NULL, 0, 492 CTL_KERN, CTL_CREATE, CTL_EOL); 493 494 if (node == NULL) 495 return; 496 497 sysctl_createv(clog, 0, &node, NULL, 498 CTLFLAG_PERMANENT | CTLFLAG_READWRITE, 499 CTLTYPE_INT, "psets_max", 500 SYSCTL_DESCR("Maximal count of the processor-sets"), 501 sysctl_psets_max, 0, &psets_max, 0, 502 CTL_CREATE, CTL_EOL); 503 } 504
Indexes created Mon Sep 22 13:09:51 GMT 2025