2 * Copyright (c) 2003,2004 The DragonFly Project. All rights reserved.
4 * This code is derived from software contributed to The DragonFly Project
5 * by Matthew Dillon <dillon@backplane.com>
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
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
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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
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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
44 #include <sys/param.h>
45 #include <sys/systm.h>
46 #include <sys/kernel.h>
48 #include <sys/rtprio.h>
49 #include <sys/queue.h>
50 #include <sys/thread2.h>
51 #include <sys/sysctl.h>
53 #include <sys/kthread.h>
54 #include <machine/cpu.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>
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 */
81 static int panic_ipiq_cpu = -1;
82 static int panic_ipiq_count = 100;
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,
99 SYSCTL_INT(_lwkt, OID_AUTO, ipiq_debug, CTLFLAG_RW, &ipiq_debug, 0,
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, "");
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
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)
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)
160 struct globaldata *gd = mycpu;
162 logipiq(send_norm, func, arg1, arg2, gd, target);
165 func(arg1, arg2, NULL);
166 logipiq(send_end, func, arg1, arg2, gd, target);
170 ++gd->gd_intr_nesting_level;
172 if (gd->gd_intr_nesting_level > 20)
173 panic("lwkt_send_ipiq: TOO HEAVILY NESTED!");
175 KKASSERT(curthread->td_critcount);
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();
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);
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);
202 #if defined(__i386__)
203 write_eflags(eflags);
204 #elif defined(__x86_64__)
205 write_rflags(rflags);
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;
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);
227 if (ipiq_optimized == 0) {
228 logipiq(cpu_send, func, arg1, arg2, gd, target);
229 cpu_send_ipiq(target->gd_cpuid);
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
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)
257 struct globaldata *gd = mycpu;
259 KKASSERT(target != gd);
261 logipiq(send_pasv, func, arg1, arg2, gd, target);
262 ++gd->gd_intr_nesting_level;
264 if (gd->gd_intr_nesting_level > 20)
265 panic("lwkt_send_ipiq: TOO HEAVILY NESTED!");
267 KKASSERT(curthread->td_critcount);
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();
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);
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);
295 #if defined(__i386__)
296 write_eflags(eflags);
297 #elif defined(__x86_64__)
298 write_rflags(rflags);
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;
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).
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)
335 struct globaldata *gd = mycpu;
337 logipiq(send_nbio, func, arg1, arg2, gd, target);
338 KKASSERT(curthread->td_critcount);
340 func(arg1, arg2, NULL);
341 logipiq(send_end, func, arg1, arg2, gd, target);
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);
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;
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);
365 if (ipiq_optimized == 0) {
366 logipiq(cpu_send, func, arg1, arg2, gd, target);
367 cpu_send_ipiq(target->gd_cpuid);
373 logipiq(send_end, func, arg1, arg2, gd, target);
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)
396 mask &= ~stopped_cpus;
398 cpuid = BSFCPUMASK(mask);
399 lwkt_send_ipiq3(globaldata_find(cpuid), func, arg1, arg2);
400 mask &= ~CPUMASK(cpuid);
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
418 lwkt_wait_ipiq(globaldata_t target, int seq)
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();
432 DEBUG_PUSH_INFO("wait_ipiq");
433 while ((int)(ip->ip_xindex - seq) < 0) {
438 kprintf("LWKT_WAIT_IPIQ WARNING! %d wait %d (%d)\n", mycpu->gd_cpuid, target->gd_cpuid, ip->ip_xindex - seq);
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).
449 #if defined(__i386__)
450 write_eflags(eflags);
451 #elif defined(__x86_64__)
452 write_rflags(rflags);
459 lwkt_seq_ipiq(globaldata_t target)
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.
483 lwkt_process_ipiq(void)
485 globaldata_t gd = mycpu;
491 for (n = 0; n < ncpus; ++n) {
492 if (n != gd->gd_cpuid) {
493 sgd = globaldata_find(n);
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)
510 lwkt_process_ipiq_frame(struct intrframe *frame)
512 globaldata_t gd = mycpu;
518 for (n = 0; n < ncpus; ++n) {
519 if (n != gd->gd_cpuid) {
520 sgd = globaldata_find(n);
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)
537 static int iqticks[SMP_MAXCPU];
538 static int iqcount[SMP_MAXCPU];
541 static int iqterm[SMP_MAXCPU];
545 lwkt_process_ipiq_core(globaldata_t sgd, lwkt_ipiq_t ip,
546 struct intrframe *frame)
548 globaldata_t mygd = mycpu;
551 ipifunc3_t copy_func;
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",
563 mygd->gd_curthread->td_cscount,
564 mygd->gd_spinlocks_wr);
565 iqcount[mygd->gd_cpuid] = 0;
567 if (++iqterm[mygd->gd_cpuid] > 10)
568 panic("cpu %d ipiq maxed", mygd->gd_cpuid);
571 for (i = 0; i < ncpus; ++i) {
572 if (globaldata_find(i)->gd_infomsg)
573 kprintf(" %s", globaldata_find(i)->gd_infomsg);
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);
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;
606 copy_func = ip->ip_func[ri];
607 copy_arg1 = ip->ip_arg1[ri];
608 copy_arg2 = ip->ip_arg2[ri];
611 KKASSERT((ip->ip_rindex & MAXCPUFIFO_MASK) ==
612 ((ri + 1) & MAXCPUFIFO_MASK));
613 logipiq(receive, copy_func, copy_arg1, copy_arg2, sgd, mycpu);
615 if (ipiq_debug && (ip->ip_rindex & 0xFFFFFF) == 0) {
616 kprintf("cpu %d ipifunc %p %p %d (frame %p)\n",
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));
628 copy_func(copy_arg1, copy_arg2, frame);
630 ip->ip_xindex = ip->ip_rindex;
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) {
639 Debugger("PANIC_DEBUG");
641 panic("PANIC_DEBUG");
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);
660 lwkt_sync_ipiq(void *arg)
662 cpumask_t *cpumask = arg;
664 atomic_clear_cpumask(cpumask, mycpu->gd_cpumask);
670 lwkt_synchronize_ipiqs(const char *wmesg)
672 cpumask_t other_cpumask;
674 other_cpumask = mycpu->gd_other_cpus & smp_active_mask;
675 lwkt_send_ipiq_mask(other_cpumask, lwkt_sync_ipiq, &other_cpumask);
677 while (other_cpumask != 0) {
678 tsleep_interlock(&other_cpumask, 0);
679 if (other_cpumask != 0)
680 tsleep(&other_cpumask, PINTERLOCKED, wmesg, 0);
687 * CPU Synchronization Support
689 * lwkt_cpusync_interlock() - Place specified cpus in a quiescent state.
690 * The current cpu is placed in a hard critical
693 * lwkt_cpusync_deinterlock() - Execute cs_func on specified cpus, including
694 * current cpu if specified, then return.
697 lwkt_cpusync_simple(cpumask_t mask, cpusync_func_t func, void *arg)
699 struct lwkt_cpusync cs;
701 lwkt_cpusync_init(&cs, mask, func, arg);
702 lwkt_cpusync_interlock(&cs);
703 lwkt_cpusync_deinterlock(&cs);
708 lwkt_cpusync_interlock(lwkt_cpusync_t cs)
711 globaldata_t gd = mycpu;
715 * mask acknowledge (cs_mack): 0->mask for stage 1
717 * mack does not include the current cpu.
719 mask = cs->cs_mask & gd->gd_other_cpus & smp_active_mask;
721 crit_enter_id("cpusync");
723 DEBUG_PUSH_INFO("cpusync_interlock");
725 ++gd->gd_curthread->td_cscount;
726 lwkt_send_ipiq_mask(mask, (ipifunc1_t)lwkt_cpusync_remote1, cs);
727 logipiq2(sync_start, mask);
728 while (cs->cs_mack != mask) {
740 * Interlocked cpus have executed remote1 and are polling in remote2.
741 * To deinterlock we clear cs_mack and wait for the cpus to execute
742 * the func and set their bit in cs_mack again.
746 lwkt_cpusync_deinterlock(lwkt_cpusync_t cs)
748 globaldata_t gd = mycpu;
753 * mask acknowledge (cs_mack): mack->0->mack for stage 2
755 * Clearing cpu bits for polling cpus in cs_mack will cause them to
756 * execute stage 2, which executes the cs_func(cs_data) and then sets
757 * their bit in cs_mack again.
759 * mack does not include the current cpu.
764 if (cs->cs_func && (cs->cs_mask & gd->gd_cpumask))
765 cs->cs_func(cs->cs_data);
767 DEBUG_PUSH_INFO("cpusync_deinterlock");
768 while (cs->cs_mack != mask) {
774 * cpusyncq ipis may be left queued without the RQF flag set due to
775 * a non-zero td_cscount, so be sure to process any laggards after
776 * decrementing td_cscount.
778 --gd->gd_curthread->td_cscount;
780 logipiq2(sync_end, mask);
782 crit_exit_id("cpusync");
784 if (cs->cs_func && (cs->cs_mask & gd->gd_cpumask))
785 cs->cs_func(cs->cs_data);
792 * helper IPI remote messaging function.
794 * Called on remote cpu when a new cpu synchronization request has been
795 * sent to us. Execute the run function and adjust cs_count, then requeue
796 * the request so we spin on it.
799 lwkt_cpusync_remote1(lwkt_cpusync_t cs)
801 globaldata_t gd = mycpu;
803 atomic_set_cpumask(&cs->cs_mack, gd->gd_cpumask);
804 lwkt_cpusync_remote2(cs);
808 * helper IPI remote messaging function.
810 * Poll for the originator telling us to finish. If it hasn't, requeue
811 * our request so we spin on it.
814 lwkt_cpusync_remote2(lwkt_cpusync_t cs)
816 globaldata_t gd = mycpu;
818 if ((cs->cs_mack & gd->gd_cpumask) == 0) {
820 cs->cs_func(cs->cs_data);
821 atomic_set_cpumask(&cs->cs_mack, gd->gd_cpumask);
826 ip = &gd->gd_cpusyncq;
827 wi = ip->ip_windex & MAXCPUFIFO_MASK;
828 ip->ip_func[wi] = (ipifunc3_t)(ipifunc1_t)lwkt_cpusync_remote2;
829 ip->ip_arg1[wi] = cs;
833 if (ipiq_debug && (ip->ip_windex & 0xFFFFFF) == 0) {
834 kprintf("cpu %d cm=%016jx %016jx f=%p\n",
836 (intmax_t)cs->cs_mask, (intmax_t)cs->cs_mack,