[CELL] spufs: remove unused file argument from spufs_run_spu()
[linux-2.6-block.git] / arch / powerpc / platforms / cell / spufs / sched.c
CommitLineData
8b3d6663
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1/* sched.c - SPU scheduler.
2 *
3 * Copyright (C) IBM 2005
4 * Author: Mark Nutter <mnutter@us.ibm.com>
5 *
a68cf983 6 * 2006-03-31 NUMA domains added.
8b3d6663
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7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2, or (at your option)
11 * any later version.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
21 */
22
3b3d22cb
AB
23#undef DEBUG
24
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25#include <linux/module.h>
26#include <linux/errno.h>
27#include <linux/sched.h>
28#include <linux/kernel.h>
29#include <linux/mm.h>
30#include <linux/completion.h>
31#include <linux/vmalloc.h>
32#include <linux/smp.h>
8b3d6663
AB
33#include <linux/stddef.h>
34#include <linux/unistd.h>
a68cf983
MN
35#include <linux/numa.h>
36#include <linux/mutex.h>
86767277 37#include <linux/notifier.h>
37901802 38#include <linux/kthread.h>
65de66f0
CH
39#include <linux/pid_namespace.h>
40#include <linux/proc_fs.h>
41#include <linux/seq_file.h>
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AB
42
43#include <asm/io.h>
44#include <asm/mmu_context.h>
45#include <asm/spu.h>
46#include <asm/spu_csa.h>
a91942ae 47#include <asm/spu_priv1.h>
8b3d6663
AB
48#include "spufs.h"
49
8b3d6663 50struct spu_prio_array {
72cb3608 51 DECLARE_BITMAP(bitmap, MAX_PRIO);
079cdb61
CH
52 struct list_head runq[MAX_PRIO];
53 spinlock_t runq_lock;
a68cf983
MN
54 struct list_head active_list[MAX_NUMNODES];
55 struct mutex active_mutex[MAX_NUMNODES];
65de66f0
CH
56 int nr_active[MAX_NUMNODES];
57 int nr_waiting;
8b3d6663
AB
58};
59
65de66f0 60static unsigned long spu_avenrun[3];
a68cf983 61static struct spu_prio_array *spu_prio;
37901802
CH
62static struct task_struct *spusched_task;
63static struct timer_list spusched_timer;
8b3d6663 64
fe443ef2
CH
65/*
66 * Priority of a normal, non-rt, non-niced'd process (aka nice level 0).
67 */
68#define NORMAL_PRIO 120
69
70/*
71 * Frequency of the spu scheduler tick. By default we do one SPU scheduler
72 * tick for every 10 CPU scheduler ticks.
73 */
74#define SPUSCHED_TICK (10)
75
76/*
77 * These are the 'tuning knobs' of the scheduler:
78 *
60e24239
JK
79 * Minimum timeslice is 5 msecs (or 1 spu scheduler tick, whichever is
80 * larger), default timeslice is 100 msecs, maximum timeslice is 800 msecs.
fe443ef2 81 */
60e24239
JK
82#define MIN_SPU_TIMESLICE max(5 * HZ / (1000 * SPUSCHED_TICK), 1)
83#define DEF_SPU_TIMESLICE (100 * HZ / (1000 * SPUSCHED_TICK))
fe443ef2
CH
84
85#define MAX_USER_PRIO (MAX_PRIO - MAX_RT_PRIO)
86#define SCALE_PRIO(x, prio) \
87 max(x * (MAX_PRIO - prio) / (MAX_USER_PRIO / 2), MIN_SPU_TIMESLICE)
88
89/*
90 * scale user-nice values [ -20 ... 0 ... 19 ] to time slice values:
91 * [800ms ... 100ms ... 5ms]
92 *
93 * The higher a thread's priority, the bigger timeslices
94 * it gets during one round of execution. But even the lowest
95 * priority thread gets MIN_TIMESLICE worth of execution time.
96 */
97void spu_set_timeslice(struct spu_context *ctx)
98{
99 if (ctx->prio < NORMAL_PRIO)
100 ctx->time_slice = SCALE_PRIO(DEF_SPU_TIMESLICE * 4, ctx->prio);
101 else
102 ctx->time_slice = SCALE_PRIO(DEF_SPU_TIMESLICE, ctx->prio);
103}
104
2cf2b3b4
CH
105/*
106 * Update scheduling information from the owning thread.
107 */
108void __spu_update_sched_info(struct spu_context *ctx)
109{
476273ad
CH
110 /*
111 * 32-Bit assignment are atomic on powerpc, and we don't care about
112 * memory ordering here because retriving the controlling thread is
113 * per defintion racy.
114 */
115 ctx->tid = current->pid;
116
2cf2b3b4
CH
117 /*
118 * We do our own priority calculations, so we normally want
119 * ->static_prio to start with. Unfortunately thies field
120 * contains junk for threads with a realtime scheduling
121 * policy so we have to look at ->prio in this case.
122 */
123 if (rt_prio(current->prio))
124 ctx->prio = current->prio;
125 else
126 ctx->prio = current->static_prio;
127 ctx->policy = current->policy;
ea1ae594
CH
128
129 /*
130 * A lot of places that don't hold active_mutex poke into
131 * cpus_allowed, including grab_runnable_context which
132 * already holds the runq_lock. So abuse runq_lock
133 * to protect this field aswell.
134 */
135 spin_lock(&spu_prio->runq_lock);
136 ctx->cpus_allowed = current->cpus_allowed;
137 spin_unlock(&spu_prio->runq_lock);
2cf2b3b4
CH
138}
139
140void spu_update_sched_info(struct spu_context *ctx)
141{
142 int node = ctx->spu->node;
143
144 mutex_lock(&spu_prio->active_mutex[node]);
145 __spu_update_sched_info(ctx);
146 mutex_unlock(&spu_prio->active_mutex[node]);
147}
148
ea1ae594 149static int __node_allowed(struct spu_context *ctx, int node)
8b3d6663 150{
ea1ae594
CH
151 if (nr_cpus_node(node)) {
152 cpumask_t mask = node_to_cpumask(node);
8b3d6663 153
ea1ae594
CH
154 if (cpus_intersects(mask, ctx->cpus_allowed))
155 return 1;
156 }
157
158 return 0;
159}
160
161static int node_allowed(struct spu_context *ctx, int node)
162{
163 int rval;
164
165 spin_lock(&spu_prio->runq_lock);
166 rval = __node_allowed(ctx, node);
167 spin_unlock(&spu_prio->runq_lock);
168
169 return rval;
8b3d6663
AB
170}
171
202557d2
CH
172/**
173 * spu_add_to_active_list - add spu to active list
174 * @spu: spu to add to the active list
175 */
176static void spu_add_to_active_list(struct spu *spu)
177{
65de66f0
CH
178 int node = spu->node;
179
180 mutex_lock(&spu_prio->active_mutex[node]);
181 spu_prio->nr_active[node]++;
182 list_add_tail(&spu->list, &spu_prio->active_list[node]);
183 mutex_unlock(&spu_prio->active_mutex[node]);
202557d2
CH
184}
185
37901802
CH
186static void __spu_remove_from_active_list(struct spu *spu)
187{
188 list_del_init(&spu->list);
65de66f0 189 spu_prio->nr_active[spu->node]--;
37901802
CH
190}
191
202557d2
CH
192/**
193 * spu_remove_from_active_list - remove spu from active list
194 * @spu: spu to remove from the active list
202557d2 195 */
678b2ff1 196static void spu_remove_from_active_list(struct spu *spu)
202557d2
CH
197{
198 int node = spu->node;
202557d2
CH
199
200 mutex_lock(&spu_prio->active_mutex[node]);
37901802 201 __spu_remove_from_active_list(spu);
202557d2 202 mutex_unlock(&spu_prio->active_mutex[node]);
202557d2
CH
203}
204
86767277
AB
205static BLOCKING_NOTIFIER_HEAD(spu_switch_notifier);
206
207static void spu_switch_notify(struct spu *spu, struct spu_context *ctx)
208{
209 blocking_notifier_call_chain(&spu_switch_notifier,
210 ctx ? ctx->object_id : 0, spu);
211}
212
213int spu_switch_event_register(struct notifier_block * n)
214{
215 return blocking_notifier_chain_register(&spu_switch_notifier, n);
216}
217
218int spu_switch_event_unregister(struct notifier_block * n)
219{
220 return blocking_notifier_chain_unregister(&spu_switch_notifier, n);
221}
222
202557d2
CH
223/**
224 * spu_bind_context - bind spu context to physical spu
225 * @spu: physical spu to bind to
226 * @ctx: context to bind
227 */
228static void spu_bind_context(struct spu *spu, struct spu_context *ctx)
8b3d6663 229{
a68cf983
MN
230 pr_debug("%s: pid=%d SPU=%d NODE=%d\n", __FUNCTION__, current->pid,
231 spu->number, spu->node);
27ec41d3 232 spuctx_switch_state(ctx, SPU_UTIL_SYSTEM);
e9f8a0b6
CH
233
234 ctx->stats.slb_flt_base = spu->stats.slb_flt;
235 ctx->stats.class2_intr_base = spu->stats.class2_intr;
236
8b3d6663
AB
237 spu->ctx = ctx;
238 spu->flags = 0;
239 ctx->spu = spu;
240 ctx->ops = &spu_hw_ops;
241 spu->pid = current->pid;
94b2a439 242 spu_associate_mm(spu, ctx->owner);
8b3d6663
AB
243 spu->ibox_callback = spufs_ibox_callback;
244 spu->wbox_callback = spufs_wbox_callback;
5110459f 245 spu->stop_callback = spufs_stop_callback;
a33a7d73 246 spu->mfc_callback = spufs_mfc_callback;
9add11da 247 spu->dma_callback = spufs_dma_callback;
8b3d6663 248 mb();
5110459f 249 spu_unmap_mappings(ctx);
8b3d6663 250 spu_restore(&ctx->csa, spu);
2a911f0b 251 spu->timestamp = jiffies;
a68cf983 252 spu_cpu_affinity_set(spu, raw_smp_processor_id());
86767277 253 spu_switch_notify(spu, ctx);
81998baf 254 ctx->state = SPU_STATE_RUNNABLE;
27ec41d3
AD
255
256 spuctx_switch_state(ctx, SPU_UTIL_IDLE_LOADED);
8b3d6663
AB
257}
258
202557d2
CH
259/**
260 * spu_unbind_context - unbind spu context from physical spu
261 * @spu: physical spu to unbind from
262 * @ctx: context to unbind
202557d2 263 */
678b2ff1 264static void spu_unbind_context(struct spu *spu, struct spu_context *ctx)
8b3d6663 265{
a68cf983
MN
266 pr_debug("%s: unbind pid=%d SPU=%d NODE=%d\n", __FUNCTION__,
267 spu->pid, spu->number, spu->node);
27ec41d3 268 spuctx_switch_state(ctx, SPU_UTIL_SYSTEM);
fe2f896d 269
86767277 270 spu_switch_notify(spu, NULL);
5110459f 271 spu_unmap_mappings(ctx);
8b3d6663 272 spu_save(&ctx->csa, spu);
2a911f0b 273 spu->timestamp = jiffies;
8b3d6663
AB
274 ctx->state = SPU_STATE_SAVED;
275 spu->ibox_callback = NULL;
276 spu->wbox_callback = NULL;
5110459f 277 spu->stop_callback = NULL;
a33a7d73 278 spu->mfc_callback = NULL;
9add11da 279 spu->dma_callback = NULL;
94b2a439 280 spu_associate_mm(spu, NULL);
8b3d6663 281 spu->pid = 0;
8b3d6663 282 ctx->ops = &spu_backing_ops;
2a911f0b 283 spu->flags = 0;
8b3d6663 284 spu->ctx = NULL;
e9f8a0b6
CH
285
286 ctx->stats.slb_flt +=
287 (spu->stats.slb_flt - ctx->stats.slb_flt_base);
288 ctx->stats.class2_intr +=
289 (spu->stats.class2_intr - ctx->stats.class2_intr_base);
27ec41d3
AD
290
291 /* This maps the underlying spu state to idle */
292 spuctx_switch_state(ctx, SPU_UTIL_IDLE_LOADED);
293 ctx->spu = NULL;
8b3d6663
AB
294}
295
079cdb61
CH
296/**
297 * spu_add_to_rq - add a context to the runqueue
298 * @ctx: context to add
299 */
4e0f4ed0 300static void __spu_add_to_rq(struct spu_context *ctx)
8b3d6663 301{
27449971
CH
302 /*
303 * Unfortunately this code path can be called from multiple threads
304 * on behalf of a single context due to the way the problem state
305 * mmap support works.
306 *
307 * Fortunately we need to wake up all these threads at the same time
308 * and can simply skip the runqueue addition for every but the first
309 * thread getting into this codepath.
310 *
311 * It's still quite hacky, and long-term we should proxy all other
312 * threads through the owner thread so that spu_run is in control
313 * of all the scheduling activity for a given context.
314 */
315 if (list_empty(&ctx->rq)) {
316 list_add_tail(&ctx->rq, &spu_prio->runq[ctx->prio]);
317 set_bit(ctx->prio, spu_prio->bitmap);
318 if (!spu_prio->nr_waiting++)
319 __mod_timer(&spusched_timer, jiffies + SPUSCHED_TICK);
320 }
2a911f0b 321}
5110459f 322
4e0f4ed0 323static void __spu_del_from_rq(struct spu_context *ctx)
a475c2f4 324{
4e0f4ed0
LB
325 int prio = ctx->prio;
326
65de66f0 327 if (!list_empty(&ctx->rq)) {
c77239b8
CH
328 if (!--spu_prio->nr_waiting)
329 del_timer(&spusched_timer);
a475c2f4 330 list_del_init(&ctx->rq);
c77239b8
CH
331
332 if (list_empty(&spu_prio->runq[prio]))
333 clear_bit(prio, spu_prio->bitmap);
65de66f0 334 }
079cdb61 335}
a68cf983 336
079cdb61 337static void spu_prio_wait(struct spu_context *ctx)
8b3d6663 338{
a68cf983 339 DEFINE_WAIT(wait);
8b3d6663 340
4e0f4ed0 341 spin_lock(&spu_prio->runq_lock);
079cdb61 342 prepare_to_wait_exclusive(&ctx->stop_wq, &wait, TASK_INTERRUPTIBLE);
a68cf983 343 if (!signal_pending(current)) {
4e0f4ed0
LB
344 __spu_add_to_rq(ctx);
345 spin_unlock(&spu_prio->runq_lock);
650f8b02 346 mutex_unlock(&ctx->state_mutex);
a68cf983 347 schedule();
650f8b02 348 mutex_lock(&ctx->state_mutex);
4e0f4ed0
LB
349 spin_lock(&spu_prio->runq_lock);
350 __spu_del_from_rq(ctx);
8b3d6663 351 }
4e0f4ed0 352 spin_unlock(&spu_prio->runq_lock);
079cdb61
CH
353 __set_current_state(TASK_RUNNING);
354 remove_wait_queue(&ctx->stop_wq, &wait);
8b3d6663
AB
355}
356
079cdb61 357static struct spu *spu_get_idle(struct spu_context *ctx)
a68cf983
MN
358{
359 struct spu *spu = NULL;
360 int node = cpu_to_node(raw_smp_processor_id());
361 int n;
362
363 for (n = 0; n < MAX_NUMNODES; n++, node++) {
364 node = (node < MAX_NUMNODES) ? node : 0;
ea1ae594 365 if (!node_allowed(ctx, node))
a68cf983
MN
366 continue;
367 spu = spu_alloc_node(node);
368 if (spu)
369 break;
370 }
371 return spu;
372}
8b3d6663 373
52f04fcf
CH
374/**
375 * find_victim - find a lower priority context to preempt
376 * @ctx: canidate context for running
377 *
378 * Returns the freed physical spu to run the new context on.
379 */
380static struct spu *find_victim(struct spu_context *ctx)
381{
382 struct spu_context *victim = NULL;
383 struct spu *spu;
384 int node, n;
385
386 /*
387 * Look for a possible preemption candidate on the local node first.
388 * If there is no candidate look at the other nodes. This isn't
389 * exactly fair, but so far the whole spu schedule tries to keep
390 * a strong node affinity. We might want to fine-tune this in
391 * the future.
392 */
393 restart:
394 node = cpu_to_node(raw_smp_processor_id());
395 for (n = 0; n < MAX_NUMNODES; n++, node++) {
396 node = (node < MAX_NUMNODES) ? node : 0;
ea1ae594 397 if (!node_allowed(ctx, node))
52f04fcf
CH
398 continue;
399
400 mutex_lock(&spu_prio->active_mutex[node]);
401 list_for_each_entry(spu, &spu_prio->active_list[node], list) {
402 struct spu_context *tmp = spu->ctx;
403
fe443ef2
CH
404 if (tmp->prio > ctx->prio &&
405 (!victim || tmp->prio > victim->prio))
52f04fcf
CH
406 victim = spu->ctx;
407 }
408 mutex_unlock(&spu_prio->active_mutex[node]);
409
410 if (victim) {
411 /*
412 * This nests ctx->state_mutex, but we always lock
413 * higher priority contexts before lower priority
414 * ones, so this is safe until we introduce
415 * priority inheritance schemes.
416 */
417 if (!mutex_trylock(&victim->state_mutex)) {
418 victim = NULL;
419 goto restart;
420 }
421
422 spu = victim->spu;
423 if (!spu) {
424 /*
425 * This race can happen because we've dropped
426 * the active list mutex. No a problem, just
427 * restart the search.
428 */
429 mutex_unlock(&victim->state_mutex);
430 victim = NULL;
431 goto restart;
432 }
37901802 433 spu_remove_from_active_list(spu);
52f04fcf 434 spu_unbind_context(spu, victim);
e9f8a0b6 435 victim->stats.invol_ctx_switch++;
fe2f896d 436 spu->stats.invol_ctx_switch++;
52f04fcf 437 mutex_unlock(&victim->state_mutex);
e097b513
CH
438 /*
439 * We need to break out of the wait loop in spu_run
440 * manually to ensure this context gets put on the
441 * runqueue again ASAP.
442 */
443 wake_up(&victim->stop_wq);
52f04fcf
CH
444 return spu;
445 }
446 }
447
448 return NULL;
449}
450
079cdb61
CH
451/**
452 * spu_activate - find a free spu for a context and execute it
453 * @ctx: spu context to schedule
454 * @flags: flags (currently ignored)
455 *
08873095 456 * Tries to find a free spu to run @ctx. If no free spu is available
079cdb61
CH
457 * add the context to the runqueue so it gets woken up once an spu
458 * is available.
459 */
26bec673 460int spu_activate(struct spu_context *ctx, unsigned long flags)
8b3d6663 461{
079cdb61
CH
462 do {
463 struct spu *spu;
464
27449971
CH
465 /*
466 * If there are multiple threads waiting for a single context
467 * only one actually binds the context while the others will
468 * only be able to acquire the state_mutex once the context
469 * already is in runnable state.
470 */
471 if (ctx->spu)
472 return 0;
473
079cdb61 474 spu = spu_get_idle(ctx);
52f04fcf
CH
475 /*
476 * If this is a realtime thread we try to get it running by
477 * preempting a lower priority thread.
478 */
fe443ef2 479 if (!spu && rt_prio(ctx->prio))
52f04fcf 480 spu = find_victim(ctx);
079cdb61 481 if (spu) {
202557d2 482 spu_bind_context(spu, ctx);
37901802 483 spu_add_to_active_list(spu);
079cdb61 484 return 0;
a68cf983 485 }
079cdb61 486
50b520d4 487 spu_prio_wait(ctx);
079cdb61
CH
488 } while (!signal_pending(current));
489
490 return -ERESTARTSYS;
8b3d6663
AB
491}
492
bb5db29a
CH
493/**
494 * grab_runnable_context - try to find a runnable context
495 *
496 * Remove the highest priority context on the runqueue and return it
497 * to the caller. Returns %NULL if no runnable context was found.
498 */
ea1ae594 499static struct spu_context *grab_runnable_context(int prio, int node)
bb5db29a 500{
ea1ae594 501 struct spu_context *ctx;
bb5db29a
CH
502 int best;
503
504 spin_lock(&spu_prio->runq_lock);
505 best = sched_find_first_bit(spu_prio->bitmap);
ea1ae594 506 while (best < prio) {
bb5db29a
CH
507 struct list_head *rq = &spu_prio->runq[best];
508
ea1ae594
CH
509 list_for_each_entry(ctx, rq, rq) {
510 /* XXX(hch): check for affinity here aswell */
511 if (__node_allowed(ctx, node)) {
512 __spu_del_from_rq(ctx);
513 goto found;
514 }
515 }
516 best++;
bb5db29a 517 }
ea1ae594
CH
518 ctx = NULL;
519 found:
bb5db29a 520 spin_unlock(&spu_prio->runq_lock);
bb5db29a
CH
521 return ctx;
522}
523
524static int __spu_deactivate(struct spu_context *ctx, int force, int max_prio)
525{
526 struct spu *spu = ctx->spu;
527 struct spu_context *new = NULL;
528
529 if (spu) {
ea1ae594 530 new = grab_runnable_context(max_prio, spu->node);
bb5db29a 531 if (new || force) {
37901802 532 spu_remove_from_active_list(spu);
bb5db29a 533 spu_unbind_context(spu, ctx);
e9f8a0b6 534 ctx->stats.vol_ctx_switch++;
fe2f896d 535 spu->stats.vol_ctx_switch++;
bb5db29a
CH
536 spu_free(spu);
537 if (new)
538 wake_up(&new->stop_wq);
539 }
540
541 }
542
543 return new != NULL;
544}
545
678b2ff1
CH
546/**
547 * spu_deactivate - unbind a context from it's physical spu
548 * @ctx: spu context to unbind
549 *
550 * Unbind @ctx from the physical spu it is running on and schedule
551 * the highest priority context to run on the freed physical spu.
552 */
8b3d6663
AB
553void spu_deactivate(struct spu_context *ctx)
554{
bb5db29a 555 __spu_deactivate(ctx, 1, MAX_PRIO);
8b3d6663
AB
556}
557
ae7b4c52
CH
558/**
559 * spu_yield - yield a physical spu if others are waiting
560 * @ctx: spu context to yield
561 *
562 * Check if there is a higher priority context waiting and if yes
563 * unbind @ctx from the physical spu and schedule the highest
564 * priority context to run on the freed physical spu instead.
565 */
8b3d6663
AB
566void spu_yield(struct spu_context *ctx)
567{
e5c0b9ec
CH
568 if (!(ctx->flags & SPU_CREATE_NOSCHED)) {
569 mutex_lock(&ctx->state_mutex);
27ec41d3 570 __spu_deactivate(ctx, 0, MAX_PRIO);
e5c0b9ec
CH
571 mutex_unlock(&ctx->state_mutex);
572 }
bb5db29a 573}
8b3d6663 574
37901802 575static void spusched_tick(struct spu_context *ctx)
bb5db29a 576{
df09cf3e
CH
577 if (ctx->flags & SPU_CREATE_NOSCHED)
578 return;
579 if (ctx->policy == SCHED_FIFO)
580 return;
581
582 if (--ctx->time_slice)
37901802 583 return;
bb5db29a
CH
584
585 /*
37901802
CH
586 * Unfortunately active_mutex ranks outside of state_mutex, so
587 * we have to trylock here. If we fail give the context another
588 * tick and try again.
bb5db29a 589 */
37901802 590 if (mutex_trylock(&ctx->state_mutex)) {
7022543e 591 struct spu *spu = ctx->spu;
ea1ae594
CH
592 struct spu_context *new;
593
594 new = grab_runnable_context(ctx->prio + 1, spu->node);
37901802 595 if (new) {
bb5db29a 596
37901802
CH
597 __spu_remove_from_active_list(spu);
598 spu_unbind_context(spu, ctx);
e9f8a0b6 599 ctx->stats.invol_ctx_switch++;
fe2f896d 600 spu->stats.invol_ctx_switch++;
37901802
CH
601 spu_free(spu);
602 wake_up(&new->stop_wq);
603 /*
604 * We need to break out of the wait loop in
605 * spu_run manually to ensure this context
606 * gets put on the runqueue again ASAP.
607 */
608 wake_up(&ctx->stop_wq);
609 }
fe443ef2 610 spu_set_timeslice(ctx);
37901802 611 mutex_unlock(&ctx->state_mutex);
bb5db29a 612 } else {
37901802 613 ctx->time_slice++;
8b3d6663 614 }
8b3d6663
AB
615}
616
65de66f0
CH
617/**
618 * count_active_contexts - count nr of active tasks
619 *
620 * Return the number of tasks currently running or waiting to run.
621 *
622 * Note that we don't take runq_lock / active_mutex here. Reading
623 * a single 32bit value is atomic on powerpc, and we don't care
624 * about memory ordering issues here.
625 */
626static unsigned long count_active_contexts(void)
627{
628 int nr_active = 0, node;
629
630 for (node = 0; node < MAX_NUMNODES; node++)
631 nr_active += spu_prio->nr_active[node];
632 nr_active += spu_prio->nr_waiting;
633
634 return nr_active;
635}
636
637/**
638 * spu_calc_load - given tick count, update the avenrun load estimates.
639 * @tick: tick count
640 *
641 * No locking against reading these values from userspace, as for
642 * the CPU loadavg code.
643 */
644static void spu_calc_load(unsigned long ticks)
645{
646 unsigned long active_tasks; /* fixed-point */
647 static int count = LOAD_FREQ;
648
649 count -= ticks;
650
651 if (unlikely(count < 0)) {
652 active_tasks = count_active_contexts() * FIXED_1;
653 do {
654 CALC_LOAD(spu_avenrun[0], EXP_1, active_tasks);
655 CALC_LOAD(spu_avenrun[1], EXP_5, active_tasks);
656 CALC_LOAD(spu_avenrun[2], EXP_15, active_tasks);
657 count += LOAD_FREQ;
658 } while (count < 0);
659 }
660}
661
37901802
CH
662static void spusched_wake(unsigned long data)
663{
664 mod_timer(&spusched_timer, jiffies + SPUSCHED_TICK);
665 wake_up_process(spusched_task);
65de66f0 666 spu_calc_load(SPUSCHED_TICK);
37901802
CH
667}
668
669static int spusched_thread(void *unused)
670{
671 struct spu *spu, *next;
672 int node;
673
37901802
CH
674 while (!kthread_should_stop()) {
675 set_current_state(TASK_INTERRUPTIBLE);
676 schedule();
677 for (node = 0; node < MAX_NUMNODES; node++) {
678 mutex_lock(&spu_prio->active_mutex[node]);
679 list_for_each_entry_safe(spu, next,
680 &spu_prio->active_list[node],
681 list)
682 spusched_tick(spu->ctx);
683 mutex_unlock(&spu_prio->active_mutex[node]);
684 }
685 }
686
37901802
CH
687 return 0;
688}
689
65de66f0
CH
690#define LOAD_INT(x) ((x) >> FSHIFT)
691#define LOAD_FRAC(x) LOAD_INT(((x) & (FIXED_1-1)) * 100)
692
693static int show_spu_loadavg(struct seq_file *s, void *private)
694{
695 int a, b, c;
696
697 a = spu_avenrun[0] + (FIXED_1/200);
698 b = spu_avenrun[1] + (FIXED_1/200);
699 c = spu_avenrun[2] + (FIXED_1/200);
700
701 /*
702 * Note that last_pid doesn't really make much sense for the
703 * SPU loadavg (it even seems very odd on the CPU side..),
704 * but we include it here to have a 100% compatible interface.
705 */
706 seq_printf(s, "%d.%02d %d.%02d %d.%02d %ld/%d %d\n",
707 LOAD_INT(a), LOAD_FRAC(a),
708 LOAD_INT(b), LOAD_FRAC(b),
709 LOAD_INT(c), LOAD_FRAC(c),
710 count_active_contexts(),
711 atomic_read(&nr_spu_contexts),
712 current->nsproxy->pid_ns->last_pid);
713 return 0;
714}
715
716static int spu_loadavg_open(struct inode *inode, struct file *file)
717{
718 return single_open(file, show_spu_loadavg, NULL);
719}
720
721static const struct file_operations spu_loadavg_fops = {
722 .open = spu_loadavg_open,
723 .read = seq_read,
724 .llseek = seq_lseek,
725 .release = single_release,
726};
727
8b3d6663
AB
728int __init spu_sched_init(void)
729{
65de66f0
CH
730 struct proc_dir_entry *entry;
731 int err = -ENOMEM, i;
8b3d6663 732
a68cf983 733 spu_prio = kzalloc(sizeof(struct spu_prio_array), GFP_KERNEL);
37901802 734 if (!spu_prio)
65de66f0 735 goto out;
37901802 736
8b3d6663 737 for (i = 0; i < MAX_PRIO; i++) {
079cdb61 738 INIT_LIST_HEAD(&spu_prio->runq[i]);
a68cf983 739 __clear_bit(i, spu_prio->bitmap);
8b3d6663 740 }
a68cf983
MN
741 __set_bit(MAX_PRIO, spu_prio->bitmap);
742 for (i = 0; i < MAX_NUMNODES; i++) {
743 mutex_init(&spu_prio->active_mutex[i]);
744 INIT_LIST_HEAD(&spu_prio->active_list[i]);
8b3d6663 745 }
079cdb61 746 spin_lock_init(&spu_prio->runq_lock);
37901802 747
c77239b8
CH
748 setup_timer(&spusched_timer, spusched_wake, 0);
749
37901802
CH
750 spusched_task = kthread_run(spusched_thread, NULL, "spusched");
751 if (IS_ERR(spusched_task)) {
65de66f0
CH
752 err = PTR_ERR(spusched_task);
753 goto out_free_spu_prio;
37901802 754 }
f3f59bec 755
65de66f0
CH
756 entry = create_proc_entry("spu_loadavg", 0, NULL);
757 if (!entry)
758 goto out_stop_kthread;
759 entry->proc_fops = &spu_loadavg_fops;
760
f3f59bec
JK
761 pr_debug("spusched: tick: %d, min ticks: %d, default ticks: %d\n",
762 SPUSCHED_TICK, MIN_SPU_TIMESLICE, DEF_SPU_TIMESLICE);
8b3d6663 763 return 0;
37901802 764
65de66f0
CH
765 out_stop_kthread:
766 kthread_stop(spusched_task);
767 out_free_spu_prio:
768 kfree(spu_prio);
769 out:
770 return err;
8b3d6663
AB
771}
772
d1450317 773void spu_sched_exit(void)
8b3d6663 774{
a68cf983
MN
775 struct spu *spu, *tmp;
776 int node;
777
65de66f0
CH
778 remove_proc_entry("spu_loadavg", NULL);
779
c77239b8 780 del_timer_sync(&spusched_timer);
37901802
CH
781 kthread_stop(spusched_task);
782
a68cf983
MN
783 for (node = 0; node < MAX_NUMNODES; node++) {
784 mutex_lock(&spu_prio->active_mutex[node]);
785 list_for_each_entry_safe(spu, tmp, &spu_prio->active_list[node],
786 list) {
787 list_del_init(&spu->list);
788 spu_free(spu);
789 }
790 mutex_unlock(&spu_prio->active_mutex[node]);
8b3d6663 791 }
a68cf983 792 kfree(spu_prio);
8b3d6663 793}