kern - Convert aio from zalloc to objcache
[dragonfly.git] / sys / kern / lwkt_ipiq.c
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1 /*
2 * Copyright (c) 2003,2004 The DragonFly Project. All rights reserved.
3 *
4 * This code is derived from software contributed to The DragonFly Project
5 * by Matthew Dillon <dillon@backplane.com>
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:
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.
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.
34 * $DragonFly: src/sys/kern/lwkt_ipiq.c,v 1.27 2008/05/18 20:57:56 nth Exp $
38 * This module implements IPI message queueing and the MI portion of IPI
39 * message processing.
42 #include "opt_ddb.h"
44 #include <sys/param.h>
45 #include <sys/systm.h>
46 #include <sys/kernel.h>
47 #include <sys/proc.h>
48 #include <sys/rtprio.h>
49 #include <sys/queue.h>
50 #include <sys/thread2.h>
51 #include <sys/sysctl.h>
52 #include <sys/ktr.h>
53 #include <sys/kthread.h>
54 #include <machine/cpu.h>
55 #include <sys/lock.h>
56 #include <sys/caps.h>
58 #include <vm/vm.h>
59 #include <vm/vm_param.h>
60 #include <vm/vm_kern.h>
61 #include <vm/vm_object.h>
62 #include <vm/vm_page.h>
63 #include <vm/vm_map.h>
64 #include <vm/vm_pager.h>
65 #include <vm/vm_extern.h>
66 #include <vm/vm_zone.h>
68 #include <machine/stdarg.h>
69 #include <machine/smp.h>
70 #include <machine/atomic.h>
72 #ifdef SMP
73 static __int64_t ipiq_count; /* total calls to lwkt_send_ipiq*() */
74 static __int64_t ipiq_fifofull; /* number of fifo full conditions detected */
75 static __int64_t ipiq_avoided; /* interlock with target avoids cpu ipi */
76 static __int64_t ipiq_passive; /* passive IPI messages */
77 static __int64_t ipiq_cscount; /* number of cpu synchronizations */
78 static int ipiq_optimized = 1; /* XXX temporary sysctl */
79 static int ipiq_debug; /* set to 1 for debug */
80 #ifdef PANIC_DEBUG
81 static int panic_ipiq_cpu = -1;
82 static int panic_ipiq_count = 100;
83 #endif
84 #endif
86 #ifdef SMP
87 SYSCTL_QUAD(_lwkt, OID_AUTO, ipiq_count, CTLFLAG_RW, &ipiq_count, 0,
88 "Number of IPI's sent");
89 SYSCTL_QUAD(_lwkt, OID_AUTO, ipiq_fifofull, CTLFLAG_RW, &ipiq_fifofull, 0,
90 "Number of fifo full conditions detected");
91 SYSCTL_QUAD(_lwkt, OID_AUTO, ipiq_avoided, CTLFLAG_RW, &ipiq_avoided, 0,
92 "Number of IPI's avoided by interlock with target cpu");
93 SYSCTL_QUAD(_lwkt, OID_AUTO, ipiq_passive, CTLFLAG_RW, &ipiq_passive, 0,
94 "Number of passive IPI messages sent");
95 SYSCTL_QUAD(_lwkt, OID_AUTO, ipiq_cscount, CTLFLAG_RW, &ipiq_cscount, 0,
96 "Number of cpu synchronizations");
97 SYSCTL_INT(_lwkt, OID_AUTO, ipiq_optimized, CTLFLAG_RW, &ipiq_optimized, 0,
98 "");
99 SYSCTL_INT(_lwkt, OID_AUTO, ipiq_debug, CTLFLAG_RW, &ipiq_debug, 0,
100 "");
101 #ifdef PANIC_DEBUG
102 SYSCTL_INT(_lwkt, OID_AUTO, panic_ipiq_cpu, CTLFLAG_RW, &panic_ipiq_cpu, 0, "");
103 SYSCTL_INT(_lwkt, OID_AUTO, panic_ipiq_count, CTLFLAG_RW, &panic_ipiq_count, 0, "");
104 #endif
106 #define IPIQ_STRING "func=%p arg1=%p arg2=%d scpu=%d dcpu=%d"
107 #define IPIQ_ARG_SIZE (sizeof(void *) * 2 + sizeof(int) * 3)
109 #if !defined(KTR_IPIQ)
110 #define KTR_IPIQ KTR_ALL
111 #endif
112 KTR_INFO_MASTER(ipiq);
113 KTR_INFO(KTR_IPIQ, ipiq, send_norm, 0, IPIQ_STRING, IPIQ_ARG_SIZE);
114 KTR_INFO(KTR_IPIQ, ipiq, send_pasv, 1, IPIQ_STRING, IPIQ_ARG_SIZE);
115 KTR_INFO(KTR_IPIQ, ipiq, send_nbio, 2, IPIQ_STRING, IPIQ_ARG_SIZE);
116 KTR_INFO(KTR_IPIQ, ipiq, send_fail, 3, IPIQ_STRING, IPIQ_ARG_SIZE);
117 KTR_INFO(KTR_IPIQ, ipiq, receive, 4, IPIQ_STRING, IPIQ_ARG_SIZE);
118 KTR_INFO(KTR_IPIQ, ipiq, sync_start, 5, "cpumask=%08x", sizeof(cpumask_t));
119 KTR_INFO(KTR_IPIQ, ipiq, sync_end, 6, "cpumask=%08x", sizeof(cpumask_t));
120 KTR_INFO(KTR_IPIQ, ipiq, cpu_send, 7, IPIQ_STRING, IPIQ_ARG_SIZE);
121 KTR_INFO(KTR_IPIQ, ipiq, send_end, 8, IPIQ_STRING, IPIQ_ARG_SIZE);
123 #define logipiq(name, func, arg1, arg2, sgd, dgd) \
124 KTR_LOG(ipiq_ ## name, func, arg1, arg2, sgd->gd_cpuid, dgd->gd_cpuid)
125 #define logipiq2(name, arg) \
126 KTR_LOG(ipiq_ ## name, arg)
128 #endif /* SMP */
130 #ifdef SMP
132 static int lwkt_process_ipiq_core(globaldata_t sgd, lwkt_ipiq_t ip,
133 struct intrframe *frame);
134 static void lwkt_cpusync_remote1(lwkt_cpusync_t cs);
135 static void lwkt_cpusync_remote2(lwkt_cpusync_t cs);
138 * Send a function execution request to another cpu. The request is queued
139 * on the cpu<->cpu ipiq matrix. Each cpu owns a unique ipiq FIFO for every
140 * possible target cpu. The FIFO can be written.
142 * If the FIFO fills up we have to enable interrupts to avoid an APIC
143 * deadlock and process pending IPIQs while waiting for it to empty.
144 * Otherwise we may soft-deadlock with another cpu whos FIFO is also full.
146 * We can safely bump gd_intr_nesting_level because our crit_exit() at the
147 * end will take care of any pending interrupts.
149 * The actual hardware IPI is avoided if the target cpu is already processing
150 * the queue from a prior IPI. It is possible to pipeline IPI messages
151 * very quickly between cpus due to the FIFO hysteresis.
153 * Need not be called from a critical section.
156 lwkt_send_ipiq3(globaldata_t target, ipifunc3_t func, void *arg1, int arg2)
158 lwkt_ipiq_t ip;
159 int windex;
160 struct globaldata *gd = mycpu;
162 logipiq(send_norm, func, arg1, arg2, gd, target);
164 if (target == gd) {
165 func(arg1, arg2, NULL);
166 logipiq(send_end, func, arg1, arg2, gd, target);
167 return(0);
169 crit_enter();
170 ++gd->gd_intr_nesting_level;
171 #ifdef INVARIANTS
172 if (gd->gd_intr_nesting_level > 20)
173 panic("lwkt_send_ipiq: TOO HEAVILY NESTED!");
174 #endif
175 KKASSERT(curthread->td_critcount);
176 ++ipiq_count;
177 ip = &gd->gd_ipiq[target->gd_cpuid];
180 * Do not allow the FIFO to become full. Interrupts must be physically
181 * enabled while we liveloop to avoid deadlocking the APIC.
183 if (ip->ip_windex - ip->ip_rindex > MAXCPUFIFO / 2) {
184 #if defined(__i386__)
185 unsigned int eflags = read_eflags();
186 #elif defined(__x86_64__)
187 unsigned long rflags = read_rflags();
188 #endif
190 if (atomic_poll_acquire_int(&ip->ip_npoll) || ipiq_optimized == 0) {
191 logipiq(cpu_send, func, arg1, arg2, gd, target);
192 cpu_send_ipiq(target->gd_cpuid);
194 cpu_enable_intr();
195 ++ipiq_fifofull;
196 DEBUG_PUSH_INFO("send_ipiq3");
197 while (ip->ip_windex - ip->ip_rindex > MAXCPUFIFO / 4) {
198 KKASSERT(ip->ip_windex - ip->ip_rindex != MAXCPUFIFO - 1);
199 lwkt_process_ipiq();
201 DEBUG_POP_INFO();
202 #if defined(__i386__)
203 write_eflags(eflags);
204 #elif defined(__x86_64__)
205 write_rflags(rflags);
206 #endif
210 * Queue the new message
212 windex = ip->ip_windex & MAXCPUFIFO_MASK;
213 ip->ip_func[windex] = func;
214 ip->ip_arg1[windex] = arg1;
215 ip->ip_arg2[windex] = arg2;
216 cpu_sfence();
217 ++ip->ip_windex;
218 --gd->gd_intr_nesting_level;
221 * signal the target cpu that there is work pending.
223 if (atomic_poll_acquire_int(&ip->ip_npoll)) {
224 logipiq(cpu_send, func, arg1, arg2, gd, target);
225 cpu_send_ipiq(target->gd_cpuid);
226 } else {
227 if (ipiq_optimized == 0) {
228 logipiq(cpu_send, func, arg1, arg2, gd, target);
229 cpu_send_ipiq(target->gd_cpuid);
230 } else {
231 ++ipiq_avoided;
234 crit_exit();
236 logipiq(send_end, func, arg1, arg2, gd, target);
237 return(ip->ip_windex);
241 * Similar to lwkt_send_ipiq() but this function does not actually initiate
242 * the IPI to the target cpu unless the FIFO has become too full, so it is
243 * very fast.
245 * This function is used for non-critical IPI messages, such as memory
246 * deallocations. The queue will typically be flushed by the target cpu at
247 * the next clock interrupt.
249 * Need not be called from a critical section.
252 lwkt_send_ipiq3_passive(globaldata_t target, ipifunc3_t func,
253 void *arg1, int arg2)
255 lwkt_ipiq_t ip;
256 int windex;
257 struct globaldata *gd = mycpu;
259 KKASSERT(target != gd);
260 crit_enter();
261 logipiq(send_pasv, func, arg1, arg2, gd, target);
262 ++gd->gd_intr_nesting_level;
263 #ifdef INVARIANTS
264 if (gd->gd_intr_nesting_level > 20)
265 panic("lwkt_send_ipiq: TOO HEAVILY NESTED!");
266 #endif
267 KKASSERT(curthread->td_critcount);
268 ++ipiq_count;
269 ++ipiq_passive;
270 ip = &gd->gd_ipiq[target->gd_cpuid];
273 * Do not allow the FIFO to become full. Interrupts must be physically
274 * enabled while we liveloop to avoid deadlocking the APIC.
276 if (ip->ip_windex - ip->ip_rindex > MAXCPUFIFO / 2) {
277 #if defined(__i386__)
278 unsigned int eflags = read_eflags();
279 #elif defined(__x86_64__)
280 unsigned long rflags = read_rflags();
281 #endif
283 if (atomic_poll_acquire_int(&ip->ip_npoll) || ipiq_optimized == 0) {
284 logipiq(cpu_send, func, arg1, arg2, gd, target);
285 cpu_send_ipiq(target->gd_cpuid);
287 cpu_enable_intr();
288 ++ipiq_fifofull;
289 DEBUG_PUSH_INFO("send_ipiq3_passive");
290 while (ip->ip_windex - ip->ip_rindex > MAXCPUFIFO / 4) {
291 KKASSERT(ip->ip_windex - ip->ip_rindex != MAXCPUFIFO - 1);
292 lwkt_process_ipiq();
294 DEBUG_POP_INFO();
295 #if defined(__i386__)
296 write_eflags(eflags);
297 #elif defined(__x86_64__)
298 write_rflags(rflags);
299 #endif
303 * Queue the new message
305 windex = ip->ip_windex & MAXCPUFIFO_MASK;
306 ip->ip_func[windex] = func;
307 ip->ip_arg1[windex] = arg1;
308 ip->ip_arg2[windex] = arg2;
309 cpu_sfence();
310 ++ip->ip_windex;
311 --gd->gd_intr_nesting_level;
314 * Do not signal the target cpu, it will pick up the IPI when it next
315 * polls (typically on the next tick).
317 crit_exit();
319 logipiq(send_end, func, arg1, arg2, gd, target);
320 return(ip->ip_windex);
324 * Send an IPI request without blocking, return 0 on success, ENOENT on
325 * failure. The actual queueing of the hardware IPI may still force us
326 * to spin and process incoming IPIs but that will eventually go away
327 * when we've gotten rid of the other general IPIs.
330 lwkt_send_ipiq3_nowait(globaldata_t target, ipifunc3_t func,
331 void *arg1, int arg2)
333 lwkt_ipiq_t ip;
334 int windex;
335 struct globaldata *gd = mycpu;
337 logipiq(send_nbio, func, arg1, arg2, gd, target);
338 KKASSERT(curthread->td_critcount);
339 if (target == gd) {
340 func(arg1, arg2, NULL);
341 logipiq(send_end, func, arg1, arg2, gd, target);
342 return(0);
344 ++ipiq_count;
345 ip = &gd->gd_ipiq[target->gd_cpuid];
347 if (ip->ip_windex - ip->ip_rindex >= MAXCPUFIFO * 2 / 3) {
348 logipiq(send_fail, func, arg1, arg2, gd, target);
349 return(ENOENT);
351 windex = ip->ip_windex & MAXCPUFIFO_MASK;
352 ip->ip_func[windex] = func;
353 ip->ip_arg1[windex] = arg1;
354 ip->ip_arg2[windex] = arg2;
355 cpu_sfence();
356 ++ip->ip_windex;
359 * This isn't a passive IPI, we still have to signal the target cpu.
361 if (atomic_poll_acquire_int(&ip->ip_npoll)) {
362 logipiq(cpu_send, func, arg1, arg2, gd, target);
363 cpu_send_ipiq(target->gd_cpuid);
364 } else {
365 if (ipiq_optimized == 0) {
366 logipiq(cpu_send, func, arg1, arg2, gd, target);
367 cpu_send_ipiq(target->gd_cpuid);
368 } else {
369 ++ipiq_avoided;
373 logipiq(send_end, func, arg1, arg2, gd, target);
374 return(0);
378 * deprecated, used only by fast int forwarding.
381 lwkt_send_ipiq3_bycpu(int dcpu, ipifunc3_t func, void *arg1, int arg2)
383 return(lwkt_send_ipiq3(globaldata_find(dcpu), func, arg1, arg2));
387 * Send a message to several target cpus. Typically used for scheduling.
388 * The message will not be sent to stopped cpus.
391 lwkt_send_ipiq3_mask(cpumask_t mask, ipifunc3_t func, void *arg1, int arg2)
393 int cpuid;
394 int count = 0;
396 mask &= ~stopped_cpus;
397 while (mask) {
398 cpuid = BSFCPUMASK(mask);
399 lwkt_send_ipiq3(globaldata_find(cpuid), func, arg1, arg2);
400 mask &= ~CPUMASK(cpuid);
401 ++count;
403 return(count);
407 * Wait for the remote cpu to finish processing a function.
409 * YYY we have to enable interrupts and process the IPIQ while waiting
410 * for it to empty or we may deadlock with another cpu. Create a CPU_*()
411 * function to do this! YYY we really should 'block' here.
413 * MUST be called from a critical section. This routine may be called
414 * from an interrupt (for example, if an interrupt wakes a foreign thread
415 * up).
417 void
418 lwkt_wait_ipiq(globaldata_t target, int seq)
420 lwkt_ipiq_t ip;
421 int maxc = 100000000;
423 if (target != mycpu) {
424 ip = &mycpu->gd_ipiq[target->gd_cpuid];
425 if ((int)(ip->ip_xindex - seq) < 0) {
426 #if defined(__i386__)
427 unsigned int eflags = read_eflags();
428 #elif defined(__x86_64__)
429 unsigned long rflags = read_rflags();
430 #endif
431 cpu_enable_intr();
432 DEBUG_PUSH_INFO("wait_ipiq");
433 while ((int)(ip->ip_xindex - seq) < 0) {
434 crit_enter();
435 lwkt_process_ipiq();
436 crit_exit();
437 if (--maxc == 0)
438 kprintf("LWKT_WAIT_IPIQ WARNING! %d wait %d (%d)\n", mycpu->gd_cpuid, target->gd_cpuid, ip->ip_xindex - seq);
439 if (maxc < -1000000)
440 panic("LWKT_WAIT_IPIQ");
442 * xindex may be modified by another cpu, use a load fence
443 * to ensure that the loop does not use a speculative value
444 * (which may improve performance).
446 cpu_lfence();
448 DEBUG_POP_INFO();
449 #if defined(__i386__)
450 write_eflags(eflags);
451 #elif defined(__x86_64__)
452 write_rflags(rflags);
453 #endif
459 lwkt_seq_ipiq(globaldata_t target)
461 lwkt_ipiq_t ip;
463 ip = &mycpu->gd_ipiq[target->gd_cpuid];
464 return(ip->ip_windex);
468 * Called from IPI interrupt (like a fast interrupt), which has placed
469 * us in a critical section. The MP lock may or may not be held.
470 * May also be called from doreti or splz, or be reentrantly called
471 * indirectly through the ip_func[] we run.
473 * There are two versions, one where no interrupt frame is available (when
474 * called from the send code and from splz, and one where an interrupt
475 * frame is available.
477 * When the current cpu is mastering a cpusync we do NOT internally loop
478 * on the cpusyncq poll. We also do not re-flag a pending ipi due to
479 * the cpusyncq poll because this can cause doreti/splz to loop internally.
480 * The cpusync master's own loop must be allowed to run to avoid a deadlock.
482 void
483 lwkt_process_ipiq(void)
485 globaldata_t gd = mycpu;
486 globaldata_t sgd;
487 lwkt_ipiq_t ip;
488 int n;
490 again:
491 for (n = 0; n < ncpus; ++n) {
492 if (n != gd->gd_cpuid) {
493 sgd = globaldata_find(n);
494 ip = sgd->gd_ipiq;
495 if (ip != NULL) {
496 while (lwkt_process_ipiq_core(sgd, &ip[gd->gd_cpuid], NULL))
501 if (gd->gd_cpusyncq.ip_rindex != gd->gd_cpusyncq.ip_windex) {
502 if (lwkt_process_ipiq_core(gd, &gd->gd_cpusyncq, NULL)) {
503 if (gd->gd_curthread->td_cscount == 0)
504 goto again;
509 void
510 lwkt_process_ipiq_frame(struct intrframe *frame)
512 globaldata_t gd = mycpu;
513 globaldata_t sgd;
514 lwkt_ipiq_t ip;
515 int n;
517 again:
518 for (n = 0; n < ncpus; ++n) {
519 if (n != gd->gd_cpuid) {
520 sgd = globaldata_find(n);
521 ip = sgd->gd_ipiq;
522 if (ip != NULL) {
523 while (lwkt_process_ipiq_core(sgd, &ip[gd->gd_cpuid], frame))
528 if (gd->gd_cpusyncq.ip_rindex != gd->gd_cpusyncq.ip_windex) {
529 if (lwkt_process_ipiq_core(gd, &gd->gd_cpusyncq, frame)) {
530 if (gd->gd_curthread->td_cscount == 0)
531 goto again;
536 #if 0
537 static int iqticks[SMP_MAXCPU];
538 static int iqcount[SMP_MAXCPU];
539 #endif
540 #if 0
541 static int iqterm[SMP_MAXCPU];
542 #endif
544 static int
545 lwkt_process_ipiq_core(globaldata_t sgd, lwkt_ipiq_t ip,
546 struct intrframe *frame)
548 globaldata_t mygd = mycpu;
549 int ri;
550 int wi;
551 ipifunc3_t copy_func;
552 void *copy_arg1;
553 int copy_arg2;
555 #if 0
556 if (iqticks[mygd->gd_cpuid] != ticks) {
557 iqticks[mygd->gd_cpuid] = ticks;
558 iqcount[mygd->gd_cpuid] = 0;
560 if (++iqcount[mygd->gd_cpuid] > 3000000) {
561 kprintf("cpu %d ipiq maxed cscount %d spin %d\n",
562 mygd->gd_cpuid,
563 mygd->gd_curthread->td_cscount,
564 mygd->gd_spinlocks_wr);
565 iqcount[mygd->gd_cpuid] = 0;
566 #if 0
567 if (++iqterm[mygd->gd_cpuid] > 10)
568 panic("cpu %d ipiq maxed", mygd->gd_cpuid);
569 #endif
570 int i;
571 for (i = 0; i < ncpus; ++i) {
572 if (globaldata_find(i)->gd_infomsg)
573 kprintf(" %s", globaldata_find(i)->gd_infomsg);
575 kprintf("\n");
577 #endif
580 * Obtain the current write index, which is modified by a remote cpu.
581 * Issue a load fence to prevent speculative reads of e.g. data written
582 * by the other cpu prior to it updating the index.
584 KKASSERT(curthread->td_critcount);
585 wi = ip->ip_windex;
586 cpu_lfence();
587 ++mygd->gd_intr_nesting_level;
590 * NOTE: xindex is only updated after we are sure the function has
591 * finished execution. Beware lwkt_process_ipiq() reentrancy!
592 * The function may send an IPI which may block/drain.
594 * NOTE: Due to additional IPI operations that the callback function
595 * may make, it is possible for both rindex and windex to advance and
596 * thus for rindex to advance passed our cached windex.
598 * NOTE: A load fence is required to prevent speculative loads prior
599 * to the loading of ip_rindex. Even though stores might be
600 * ordered, loads are probably not. A memory fence is required
601 * to prevent reordering of the loads after the ip_rindex update.
603 while (wi - (ri = ip->ip_rindex) > 0) {
604 ri &= MAXCPUFIFO_MASK;
605 cpu_lfence();
606 copy_func = ip->ip_func[ri];
607 copy_arg1 = ip->ip_arg1[ri];
608 copy_arg2 = ip->ip_arg2[ri];
609 cpu_mfence();
610 ++ip->ip_rindex;
611 KKASSERT((ip->ip_rindex & MAXCPUFIFO_MASK) ==
612 ((ri + 1) & MAXCPUFIFO_MASK));
613 logipiq(receive, copy_func, copy_arg1, copy_arg2, sgd, mycpu);
614 #ifdef INVARIANTS
615 if (ipiq_debug && (ip->ip_rindex & 0xFFFFFF) == 0) {
616 kprintf("cpu %d ipifunc %p %p %d (frame %p)\n",
617 mycpu->gd_cpuid,
618 copy_func, copy_arg1, copy_arg2,
619 #if defined(__i386__)
620 (frame ? (void *)frame->if_eip : NULL));
621 #elif defined(__amd64__)
622 (frame ? (void *)frame->if_rip : NULL));
623 #else
624 NULL);
625 #endif
627 #endif
628 copy_func(copy_arg1, copy_arg2, frame);
629 cpu_sfence();
630 ip->ip_xindex = ip->ip_rindex;
632 #ifdef PANIC_DEBUG
634 * Simulate panics during the processing of an IPI
636 if (mycpu->gd_cpuid == panic_ipiq_cpu && panic_ipiq_count) {
637 if (--panic_ipiq_count == 0) {
638 #ifdef DDB
639 Debugger("PANIC_DEBUG");
640 #else
641 panic("PANIC_DEBUG");
642 #endif
645 #endif
647 --mygd->gd_intr_nesting_level;
650 * Return non-zero if there are more IPI messages pending on this
651 * ipiq. ip_npoll is left set as long as possible to reduce the
652 * number of IPIs queued by the originating cpu, but must be cleared
653 * *BEFORE* checking windex.
655 atomic_poll_release_int(&ip->ip_npoll);
656 return(wi != ip->ip_windex);
659 static void
660 lwkt_sync_ipiq(void *arg)
662 volatile cpumask_t *cpumask = arg;
664 atomic_clear_cpumask(cpumask, mycpu->gd_cpumask);
665 if (*cpumask == 0)
666 wakeup(cpumask);
669 void
670 lwkt_synchronize_ipiqs(const char *wmesg)
672 volatile cpumask_t other_cpumask;
674 other_cpumask = mycpu->gd_other_cpus & smp_active_mask;
675 lwkt_send_ipiq_mask(other_cpumask, lwkt_sync_ipiq,
676 __DEVOLATILE(void *, &other_cpumask));
678 while (other_cpumask != 0) {
679 tsleep_interlock(&other_cpumask, 0);
680 if (other_cpumask != 0)
681 tsleep(&other_cpumask, PINTERLOCKED, wmesg, 0);
685 #endif
688 * CPU Synchronization Support
690 * lwkt_cpusync_interlock() - Place specified cpus in a quiescent state.
691 * The current cpu is placed in a hard critical
692 * section.
694 * lwkt_cpusync_deinterlock() - Execute cs_func on specified cpus, including
695 * current cpu if specified, then return.
697 void
698 lwkt_cpusync_simple(cpumask_t mask, cpusync_func_t func, void *arg)
700 struct lwkt_cpusync cs;
702 lwkt_cpusync_init(&cs, mask, func, arg);
703 lwkt_cpusync_interlock(&cs);
704 lwkt_cpusync_deinterlock(&cs);
708 void
709 lwkt_cpusync_interlock(lwkt_cpusync_t cs)
711 #ifdef SMP
712 globaldata_t gd = mycpu;
713 cpumask_t mask;
716 * mask acknowledge (cs_mack): 0->mask for stage 1
718 * mack does not include the current cpu.
720 mask = cs->cs_mask & gd->gd_other_cpus & smp_active_mask;
721 cs->cs_mack = 0;
722 crit_enter_id("cpusync");
723 if (mask) {
724 DEBUG_PUSH_INFO("cpusync_interlock");
725 ++ipiq_cscount;
726 ++gd->gd_curthread->td_cscount;
727 lwkt_send_ipiq_mask(mask, (ipifunc1_t)lwkt_cpusync_remote1, cs);
728 logipiq2(sync_start, mask);
729 while (cs->cs_mack != mask) {
730 lwkt_process_ipiq();
731 cpu_pause();
733 DEBUG_POP_INFO();
735 #else
736 cs->cs_mack = 0;
737 #endif
741 * Interlocked cpus have executed remote1 and are polling in remote2.
742 * To deinterlock we clear cs_mack and wait for the cpus to execute
743 * the func and set their bit in cs_mack again.
746 void
747 lwkt_cpusync_deinterlock(lwkt_cpusync_t cs)
749 globaldata_t gd = mycpu;
750 #ifdef SMP
751 cpumask_t mask;
754 * mask acknowledge (cs_mack): mack->0->mack for stage 2
756 * Clearing cpu bits for polling cpus in cs_mack will cause them to
757 * execute stage 2, which executes the cs_func(cs_data) and then sets
758 * their bit in cs_mack again.
760 * mack does not include the current cpu.
762 mask = cs->cs_mack;
763 cpu_ccfence();
764 cs->cs_mack = 0;
765 if (cs->cs_func && (cs->cs_mask & gd->gd_cpumask))
766 cs->cs_func(cs->cs_data);
767 if (mask) {
768 DEBUG_PUSH_INFO("cpusync_deinterlock");
769 while (cs->cs_mack != mask) {
770 lwkt_process_ipiq();
771 cpu_pause();
773 DEBUG_POP_INFO();
775 * cpusyncq ipis may be left queued without the RQF flag set due to
776 * a non-zero td_cscount, so be sure to process any laggards after
777 * decrementing td_cscount.
779 --gd->gd_curthread->td_cscount;
780 lwkt_process_ipiq();
781 logipiq2(sync_end, mask);
783 crit_exit_id("cpusync");
784 #else
785 if (cs->cs_func && (cs->cs_mask & gd->gd_cpumask))
786 cs->cs_func(cs->cs_data);
787 #endif
790 #ifdef SMP
793 * helper IPI remote messaging function.
795 * Called on remote cpu when a new cpu synchronization request has been
796 * sent to us. Execute the run function and adjust cs_count, then requeue
797 * the request so we spin on it.
799 static void
800 lwkt_cpusync_remote1(lwkt_cpusync_t cs)
802 globaldata_t gd = mycpu;
804 atomic_set_cpumask(&cs->cs_mack, gd->gd_cpumask);
805 lwkt_cpusync_remote2(cs);
809 * helper IPI remote messaging function.
811 * Poll for the originator telling us to finish. If it hasn't, requeue
812 * our request so we spin on it.
814 static void
815 lwkt_cpusync_remote2(lwkt_cpusync_t cs)
817 globaldata_t gd = mycpu;
819 if ((cs->cs_mack & gd->gd_cpumask) == 0) {
820 if (cs->cs_func)
821 cs->cs_func(cs->cs_data);
822 atomic_set_cpumask(&cs->cs_mack, gd->gd_cpumask);
823 } else {
824 lwkt_ipiq_t ip;
825 int wi;
827 ip = &gd->gd_cpusyncq;
828 wi = ip->ip_windex & MAXCPUFIFO_MASK;
829 ip->ip_func[wi] = (ipifunc3_t)(ipifunc1_t)lwkt_cpusync_remote2;
830 ip->ip_arg1[wi] = cs;
831 ip->ip_arg2[wi] = 0;
832 cpu_sfence();
833 ++ip->ip_windex;
834 if (ipiq_debug && (ip->ip_windex & 0xFFFFFF) == 0) {
835 kprintf("cpu %d cm=%016jx %016jx f=%p\n",
836 gd->gd_cpuid,
837 (intmax_t)cs->cs_mask, (intmax_t)cs->cs_mack,
838 cs->cs_func);
843 #endif