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
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
36 * This module implements IPI message queueing and the MI portion of IPI
42 #include <sys/param.h>
43 #include <sys/systm.h>
44 #include <sys/kernel.h>
46 #include <sys/rtprio.h>
47 #include <sys/queue.h>
48 #include <sys/thread2.h>
49 #include <sys/sysctl.h>
51 #include <sys/kthread.h>
52 #include <machine/cpu.h>
56 #include <vm/vm_param.h>
57 #include <vm/vm_kern.h>
58 #include <vm/vm_object.h>
59 #include <vm/vm_page.h>
60 #include <vm/vm_map.h>
61 #include <vm/vm_pager.h>
62 #include <vm/vm_extern.h>
63 #include <vm/vm_zone.h>
65 #include <machine/stdarg.h>
66 #include <machine/smp.h>
67 #include <machine/atomic.h>
69 static __int64_t ipiq_count; /* total calls to lwkt_send_ipiq*() */
70 static __int64_t ipiq_fifofull; /* number of fifo full conditions detected */
71 static __int64_t ipiq_avoided; /* interlock with target avoids cpu ipi */
72 static __int64_t ipiq_passive; /* passive IPI messages */
73 static __int64_t ipiq_cscount; /* number of cpu synchronizations */
74 static int ipiq_debug; /* set to 1 for debug */
76 static int panic_ipiq_cpu = -1;
77 static int panic_ipiq_count = 100;
80 SYSCTL_QUAD(_lwkt, OID_AUTO, ipiq_count, CTLFLAG_RW, &ipiq_count, 0,
81 "Number of IPI's sent");
82 SYSCTL_QUAD(_lwkt, OID_AUTO, ipiq_fifofull, CTLFLAG_RW, &ipiq_fifofull, 0,
83 "Number of fifo full conditions detected");
84 SYSCTL_QUAD(_lwkt, OID_AUTO, ipiq_avoided, CTLFLAG_RW, &ipiq_avoided, 0,
85 "Number of IPI's avoided by interlock with target cpu");
86 SYSCTL_QUAD(_lwkt, OID_AUTO, ipiq_passive, CTLFLAG_RW, &ipiq_passive, 0,
87 "Number of passive IPI messages sent");
88 SYSCTL_QUAD(_lwkt, OID_AUTO, ipiq_cscount, CTLFLAG_RW, &ipiq_cscount, 0,
89 "Number of cpu synchronizations");
90 SYSCTL_INT(_lwkt, OID_AUTO, ipiq_debug, CTLFLAG_RW, &ipiq_debug, 0,
93 SYSCTL_INT(_lwkt, OID_AUTO, panic_ipiq_cpu, CTLFLAG_RW, &panic_ipiq_cpu, 0, "");
94 SYSCTL_INT(_lwkt, OID_AUTO, panic_ipiq_count, CTLFLAG_RW, &panic_ipiq_count, 0, "");
97 #define IPIQ_STRING "func=%p arg1=%p arg2=%d scpu=%d dcpu=%d"
98 #define IPIQ_ARGS void *func, void *arg1, int arg2, int scpu, int dcpu
100 #if !defined(KTR_IPIQ)
101 #define KTR_IPIQ KTR_ALL
103 KTR_INFO_MASTER(ipiq);
104 KTR_INFO(KTR_IPIQ, ipiq, send_norm, 0, IPIQ_STRING, IPIQ_ARGS);
105 KTR_INFO(KTR_IPIQ, ipiq, send_pasv, 1, IPIQ_STRING, IPIQ_ARGS);
106 KTR_INFO(KTR_IPIQ, ipiq, send_nbio, 2, IPIQ_STRING, IPIQ_ARGS);
107 KTR_INFO(KTR_IPIQ, ipiq, send_fail, 3, IPIQ_STRING, IPIQ_ARGS);
108 KTR_INFO(KTR_IPIQ, ipiq, receive, 4, IPIQ_STRING, IPIQ_ARGS);
109 KTR_INFO(KTR_IPIQ, ipiq, sync_start, 5, "cpumask=%08lx", unsigned long mask);
110 KTR_INFO(KTR_IPIQ, ipiq, sync_end, 6, "cpumask=%08lx", unsigned long mask);
111 KTR_INFO(KTR_IPIQ, ipiq, cpu_send, 7, IPIQ_STRING, IPIQ_ARGS);
112 KTR_INFO(KTR_IPIQ, ipiq, send_end, 8, IPIQ_STRING, IPIQ_ARGS);
114 #define logipiq(name, func, arg1, arg2, sgd, dgd) \
115 KTR_LOG(ipiq_ ## name, func, arg1, arg2, sgd->gd_cpuid, dgd->gd_cpuid)
116 #define logipiq2(name, arg) \
117 KTR_LOG(ipiq_ ## name, arg)
119 static int lwkt_process_ipiq_core(globaldata_t sgd, lwkt_ipiq_t ip,
120 struct intrframe *frame);
121 static void lwkt_cpusync_remote1(lwkt_cpusync_t cs);
122 static void lwkt_cpusync_remote2(lwkt_cpusync_t cs);
125 * Send a function execution request to another cpu. The request is queued
126 * on the cpu<->cpu ipiq matrix. Each cpu owns a unique ipiq FIFO for every
127 * possible target cpu. The FIFO can be written.
129 * If the FIFO fills up we have to enable interrupts to avoid an APIC
130 * deadlock and process pending IPIQs while waiting for it to empty.
131 * Otherwise we may soft-deadlock with another cpu whos FIFO is also full.
133 * We can safely bump gd_intr_nesting_level because our crit_exit() at the
134 * end will take care of any pending interrupts.
136 * The actual hardware IPI is avoided if the target cpu is already processing
137 * the queue from a prior IPI. It is possible to pipeline IPI messages
138 * very quickly between cpus due to the FIFO hysteresis.
140 * Need not be called from a critical section.
143 lwkt_send_ipiq3(globaldata_t target, ipifunc3_t func, void *arg1, int arg2)
147 struct globaldata *gd = mycpu;
149 logipiq(send_norm, func, arg1, arg2, gd, target);
152 func(arg1, arg2, NULL);
153 logipiq(send_end, func, arg1, arg2, gd, target);
157 ++gd->gd_intr_nesting_level;
159 if (gd->gd_intr_nesting_level > 20)
160 panic("lwkt_send_ipiq: TOO HEAVILY NESTED!");
162 KKASSERT(curthread->td_critcount);
164 ip = &gd->gd_ipiq[target->gd_cpuid];
167 * Do not allow the FIFO to become full. Interrupts must be physically
168 * enabled while we liveloop to avoid deadlocking the APIC.
170 * The target ipiq may have gotten filled up due to passive IPIs and thus
171 * not be aware that its queue is too full, so be sure to issue an
172 * ipiq interrupt to the target cpu.
174 if (ip->ip_windex - ip->ip_rindex > MAXCPUFIFO / 2) {
175 #if defined(__i386__)
176 unsigned int eflags = read_eflags();
177 #elif defined(__x86_64__)
178 unsigned long rflags = read_rflags();
183 DEBUG_PUSH_INFO("send_ipiq3");
184 while (ip->ip_windex - ip->ip_rindex > MAXCPUFIFO / 4) {
185 if (atomic_poll_acquire_int(&target->gd_npoll)) {
186 logipiq(cpu_send, func, arg1, arg2, gd, target);
187 cpu_send_ipiq(target->gd_cpuid);
189 KKASSERT(ip->ip_windex - ip->ip_rindex != MAXCPUFIFO - 1);
194 #if defined(__i386__)
195 write_eflags(eflags);
196 #elif defined(__x86_64__)
197 write_rflags(rflags);
202 * Queue the new message
204 windex = ip->ip_windex & MAXCPUFIFO_MASK;
205 ip->ip_info[windex].func = func;
206 ip->ip_info[windex].arg1 = arg1;
207 ip->ip_info[windex].arg2 = arg2;
210 atomic_set_cpumask(&target->gd_ipimask, gd->gd_cpumask);
213 * signal the target cpu that there is work pending.
215 if (atomic_poll_acquire_int(&target->gd_npoll)) {
216 logipiq(cpu_send, func, arg1, arg2, gd, target);
217 cpu_send_ipiq(target->gd_cpuid);
221 --gd->gd_intr_nesting_level;
223 logipiq(send_end, func, arg1, arg2, gd, target);
225 return(ip->ip_windex);
229 * Similar to lwkt_send_ipiq() but this function does not actually initiate
230 * the IPI to the target cpu unless the FIFO has become too full, so it is
233 * This function is used for non-critical IPI messages, such as memory
234 * deallocations. The queue will typically be flushed by the target cpu at
235 * the next clock interrupt.
237 * Need not be called from a critical section.
240 lwkt_send_ipiq3_passive(globaldata_t target, ipifunc3_t func,
241 void *arg1, int arg2)
245 struct globaldata *gd = mycpu;
247 KKASSERT(target != gd);
249 ++gd->gd_intr_nesting_level;
250 logipiq(send_pasv, func, arg1, arg2, gd, target);
252 if (gd->gd_intr_nesting_level > 20)
253 panic("lwkt_send_ipiq: TOO HEAVILY NESTED!");
255 KKASSERT(curthread->td_critcount);
258 ip = &gd->gd_ipiq[target->gd_cpuid];
261 * Do not allow the FIFO to become full. Interrupts must be physically
262 * enabled while we liveloop to avoid deadlocking the APIC.
264 if (ip->ip_windex - ip->ip_rindex > MAXCPUFIFO / 2) {
265 #if defined(__i386__)
266 unsigned int eflags = read_eflags();
267 #elif defined(__x86_64__)
268 unsigned long rflags = read_rflags();
273 DEBUG_PUSH_INFO("send_ipiq3_passive");
274 while (ip->ip_windex - ip->ip_rindex > MAXCPUFIFO / 4) {
275 if (atomic_poll_acquire_int(&target->gd_npoll)) {
276 logipiq(cpu_send, func, arg1, arg2, gd, target);
277 cpu_send_ipiq(target->gd_cpuid);
279 KKASSERT(ip->ip_windex - ip->ip_rindex != MAXCPUFIFO - 1);
284 #if defined(__i386__)
285 write_eflags(eflags);
286 #elif defined(__x86_64__)
287 write_rflags(rflags);
292 * Queue the new message
294 windex = ip->ip_windex & MAXCPUFIFO_MASK;
295 ip->ip_info[windex].func = func;
296 ip->ip_info[windex].arg1 = arg1;
297 ip->ip_info[windex].arg2 = arg2;
300 atomic_set_cpumask(&target->gd_ipimask, gd->gd_cpumask);
301 --gd->gd_intr_nesting_level;
304 * Do not signal the target cpu, it will pick up the IPI when it next
305 * polls (typically on the next tick).
308 logipiq(send_end, func, arg1, arg2, gd, target);
310 return(ip->ip_windex);
314 * Send an IPI request without blocking, return 0 on success, ENOENT on
315 * failure. The actual queueing of the hardware IPI may still force us
316 * to spin and process incoming IPIs but that will eventually go away
317 * when we've gotten rid of the other general IPIs.
320 lwkt_send_ipiq3_nowait(globaldata_t target, ipifunc3_t func,
321 void *arg1, int arg2)
325 struct globaldata *gd = mycpu;
327 logipiq(send_nbio, func, arg1, arg2, gd, target);
328 KKASSERT(curthread->td_critcount);
330 func(arg1, arg2, NULL);
331 logipiq(send_end, func, arg1, arg2, gd, target);
335 ++gd->gd_intr_nesting_level;
337 ip = &gd->gd_ipiq[target->gd_cpuid];
339 if (ip->ip_windex - ip->ip_rindex >= MAXCPUFIFO * 2 / 3) {
340 logipiq(send_fail, func, arg1, arg2, gd, target);
341 --gd->gd_intr_nesting_level;
345 windex = ip->ip_windex & MAXCPUFIFO_MASK;
346 ip->ip_info[windex].func = func;
347 ip->ip_info[windex].arg1 = arg1;
348 ip->ip_info[windex].arg2 = arg2;
351 atomic_set_cpumask(&target->gd_ipimask, gd->gd_cpumask);
354 * This isn't a passive IPI, we still have to signal the target cpu.
356 if (atomic_poll_acquire_int(&target->gd_npoll)) {
357 logipiq(cpu_send, func, arg1, arg2, gd, target);
358 cpu_send_ipiq(target->gd_cpuid);
362 --gd->gd_intr_nesting_level;
365 logipiq(send_end, func, arg1, arg2, gd, target);
370 * deprecated, used only by fast int forwarding.
373 lwkt_send_ipiq3_bycpu(int dcpu, ipifunc3_t func, void *arg1, int arg2)
375 return(lwkt_send_ipiq3(globaldata_find(dcpu), func, arg1, arg2));
379 * Send a message to several target cpus. Typically used for scheduling.
380 * The message will not be sent to stopped cpus.
383 lwkt_send_ipiq3_mask(cpumask_t mask, ipifunc3_t func, void *arg1, int arg2)
388 mask &= ~stopped_cpus;
390 cpuid = BSFCPUMASK(mask);
391 lwkt_send_ipiq3(globaldata_find(cpuid), func, arg1, arg2);
392 mask &= ~CPUMASK(cpuid);
399 * Wait for the remote cpu to finish processing a function.
401 * YYY we have to enable interrupts and process the IPIQ while waiting
402 * for it to empty or we may deadlock with another cpu. Create a CPU_*()
403 * function to do this! YYY we really should 'block' here.
405 * MUST be called from a critical section. This routine may be called
406 * from an interrupt (for example, if an interrupt wakes a foreign thread
410 lwkt_wait_ipiq(globaldata_t target, int seq)
413 int maxc = 100000000;
415 if (target != mycpu) {
416 ip = &mycpu->gd_ipiq[target->gd_cpuid];
417 if ((int)(ip->ip_xindex - seq) < 0) {
418 #if defined(__i386__)
419 unsigned int eflags = read_eflags();
420 #elif defined(__x86_64__)
421 unsigned long rflags = read_rflags();
424 DEBUG_PUSH_INFO("wait_ipiq");
425 while ((int)(ip->ip_xindex - seq) < 0) {
430 kprintf("LWKT_WAIT_IPIQ WARNING! %d wait %d (%d)\n", mycpu->gd_cpuid, target->gd_cpuid, ip->ip_xindex - seq);
432 panic("LWKT_WAIT_IPIQ");
434 * xindex may be modified by another cpu, use a load fence
435 * to ensure that the loop does not use a speculative value
436 * (which may improve performance).
441 #if defined(__i386__)
442 write_eflags(eflags);
443 #elif defined(__x86_64__)
444 write_rflags(rflags);
451 lwkt_seq_ipiq(globaldata_t target)
455 ip = &mycpu->gd_ipiq[target->gd_cpuid];
456 return(ip->ip_windex);
460 * Called from IPI interrupt (like a fast interrupt), which has placed
461 * us in a critical section. The MP lock may or may not be held.
462 * May also be called from doreti or splz, or be reentrantly called
463 * indirectly through the ip_info[].func we run.
465 * There are two versions, one where no interrupt frame is available (when
466 * called from the send code and from splz, and one where an interrupt
467 * frame is available.
469 * When the current cpu is mastering a cpusync we do NOT internally loop
470 * on the cpusyncq poll. We also do not re-flag a pending ipi due to
471 * the cpusyncq poll because this can cause doreti/splz to loop internally.
472 * The cpusync master's own loop must be allowed to run to avoid a deadlock.
475 lwkt_process_ipiq(void)
477 globaldata_t gd = mycpu;
483 ++gd->gd_processing_ipiq;
486 mask = gd->gd_ipimask;
487 atomic_clear_cpumask(&gd->gd_ipimask, mask);
489 n = BSFCPUMASK(mask);
490 if (n != gd->gd_cpuid) {
491 sgd = globaldata_find(n);
494 while (lwkt_process_ipiq_core(sgd, &ip[gd->gd_cpuid], NULL))
502 * Process pending cpusyncs. If the current thread has a cpusync
503 * active cpusync we only run the list once and do not re-flag
504 * as the thread itself is processing its interlock.
506 if (lwkt_process_ipiq_core(gd, &gd->gd_cpusyncq, NULL)) {
507 if (gd->gd_curthread->td_cscount == 0)
509 /* need_ipiq(); do not reflag */
513 * Interlock to allow more IPI interrupts. Recheck ipimask after
514 * releasing gd_npoll.
518 atomic_poll_release_int(&gd->gd_npoll);
522 --gd->gd_processing_ipiq;
526 lwkt_process_ipiq_frame(struct intrframe *frame)
528 globaldata_t gd = mycpu;
536 mask = gd->gd_ipimask;
537 atomic_clear_cpumask(&gd->gd_ipimask, mask);
539 n = BSFCPUMASK(mask);
540 if (n != gd->gd_cpuid) {
541 sgd = globaldata_find(n);
544 while (lwkt_process_ipiq_core(sgd, &ip[gd->gd_cpuid], frame))
550 if (gd->gd_cpusyncq.ip_rindex != gd->gd_cpusyncq.ip_windex) {
551 if (lwkt_process_ipiq_core(gd, &gd->gd_cpusyncq, frame)) {
552 if (gd->gd_curthread->td_cscount == 0)
554 /* need_ipiq(); do not reflag */
559 * Interlock to allow more IPI interrupts. Recheck ipimask after
560 * releasing gd_npoll.
564 atomic_poll_release_int(&gd->gd_npoll);
571 static int iqticks[SMP_MAXCPU];
572 static int iqcount[SMP_MAXCPU];
575 static int iqterm[SMP_MAXCPU];
579 lwkt_process_ipiq_core(globaldata_t sgd, lwkt_ipiq_t ip,
580 struct intrframe *frame)
582 globaldata_t mygd = mycpu;
585 ipifunc3_t copy_func;
590 if (iqticks[mygd->gd_cpuid] != ticks) {
591 iqticks[mygd->gd_cpuid] = ticks;
592 iqcount[mygd->gd_cpuid] = 0;
594 if (++iqcount[mygd->gd_cpuid] > 3000000) {
595 kprintf("cpu %d ipiq maxed cscount %d spin %d\n",
597 mygd->gd_curthread->td_cscount,
599 iqcount[mygd->gd_cpuid] = 0;
601 if (++iqterm[mygd->gd_cpuid] > 10)
602 panic("cpu %d ipiq maxed", mygd->gd_cpuid);
605 for (i = 0; i < ncpus; ++i) {
606 if (globaldata_find(i)->gd_infomsg)
607 kprintf(" %s", globaldata_find(i)->gd_infomsg);
614 * Clear the originating core from our ipimask, we will process all
617 * Obtain the current write index, which is modified by a remote cpu.
618 * Issue a load fence to prevent speculative reads of e.g. data written
619 * by the other cpu prior to it updating the index.
621 KKASSERT(curthread->td_critcount);
624 ++mygd->gd_intr_nesting_level;
627 * NOTE: xindex is only updated after we are sure the function has
628 * finished execution. Beware lwkt_process_ipiq() reentrancy!
629 * The function may send an IPI which may block/drain.
631 * NOTE: Due to additional IPI operations that the callback function
632 * may make, it is possible for both rindex and windex to advance and
633 * thus for rindex to advance passed our cached windex.
635 * NOTE: A load fence is required to prevent speculative loads prior
636 * to the loading of ip_rindex. Even though stores might be
637 * ordered, loads are probably not. A memory fence is required
638 * to prevent reordering of the loads after the ip_rindex update.
640 * NOTE: Single pass only. Returns non-zero if the queue is not empty
643 while (wi - (ri = ip->ip_rindex) > 0) {
644 ri &= MAXCPUFIFO_MASK;
646 copy_func = ip->ip_info[ri].func;
647 copy_arg1 = ip->ip_info[ri].arg1;
648 copy_arg2 = ip->ip_info[ri].arg2;
651 KKASSERT((ip->ip_rindex & MAXCPUFIFO_MASK) ==
652 ((ri + 1) & MAXCPUFIFO_MASK));
653 logipiq(receive, copy_func, copy_arg1, copy_arg2, sgd, mycpu);
655 if (ipiq_debug && (ip->ip_rindex & 0xFFFFFF) == 0) {
656 kprintf("cpu %d ipifunc %p %p %d (frame %p)\n",
658 copy_func, copy_arg1, copy_arg2,
659 #if defined(__i386__)
660 (frame ? (void *)frame->if_eip : NULL));
661 #elif defined(__x86_64__)
662 (frame ? (void *)frame->if_rip : NULL));
668 copy_func(copy_arg1, copy_arg2, frame);
670 ip->ip_xindex = ip->ip_rindex;
674 * Simulate panics during the processing of an IPI
676 if (mycpu->gd_cpuid == panic_ipiq_cpu && panic_ipiq_count) {
677 if (--panic_ipiq_count == 0) {
679 Debugger("PANIC_DEBUG");
681 panic("PANIC_DEBUG");
687 --mygd->gd_intr_nesting_level;
690 * Return non-zero if there is still more in the queue.
693 return (ip->ip_rindex != ip->ip_windex);
697 lwkt_sync_ipiq(void *arg)
699 volatile cpumask_t *cpumask = arg;
701 atomic_clear_cpumask(cpumask, mycpu->gd_cpumask);
707 lwkt_synchronize_ipiqs(const char *wmesg)
709 volatile cpumask_t other_cpumask;
711 other_cpumask = mycpu->gd_other_cpus & smp_active_mask;
712 lwkt_send_ipiq_mask(other_cpumask, lwkt_sync_ipiq,
713 __DEVOLATILE(void *, &other_cpumask));
715 while (other_cpumask != 0) {
716 tsleep_interlock(&other_cpumask, 0);
717 if (other_cpumask != 0)
718 tsleep(&other_cpumask, PINTERLOCKED, wmesg, 0);
723 * CPU Synchronization Support
725 * lwkt_cpusync_interlock() - Place specified cpus in a quiescent state.
726 * The current cpu is placed in a hard critical
729 * lwkt_cpusync_deinterlock() - Execute cs_func on specified cpus, including
730 * current cpu if specified, then return.
733 lwkt_cpusync_simple(cpumask_t mask, cpusync_func_t func, void *arg)
735 struct lwkt_cpusync cs;
737 lwkt_cpusync_init(&cs, mask, func, arg);
738 lwkt_cpusync_interlock(&cs);
739 lwkt_cpusync_deinterlock(&cs);
744 lwkt_cpusync_interlock(lwkt_cpusync_t cs)
747 const char *smsg = "SMPSYNL";
749 globaldata_t gd = mycpu;
753 * mask acknowledge (cs_mack): 0->mask for stage 1
755 * mack does not include the current cpu.
757 mask = cs->cs_mask & gd->gd_other_cpus & smp_active_mask;
759 crit_enter_id("cpusync");
761 DEBUG_PUSH_INFO("cpusync_interlock");
763 ++gd->gd_curthread->td_cscount;
764 lwkt_send_ipiq_mask(mask, (ipifunc1_t)lwkt_cpusync_remote1, cs);
765 logipiq2(sync_start, (long)mask);
767 if (gd->gd_curthread->td_wmesg == NULL)
768 gd->gd_curthread->td_wmesg = smsg;
770 while (cs->cs_mack != mask) {
775 if (gd->gd_curthread->td_wmesg == smsg)
776 gd->gd_curthread->td_wmesg = NULL;
783 * Interlocked cpus have executed remote1 and are polling in remote2.
784 * To deinterlock we clear cs_mack and wait for the cpus to execute
785 * the func and set their bit in cs_mack again.
789 lwkt_cpusync_deinterlock(lwkt_cpusync_t cs)
791 globaldata_t gd = mycpu;
793 const char *smsg = "SMPSYNU";
798 * mask acknowledge (cs_mack): mack->0->mack for stage 2
800 * Clearing cpu bits for polling cpus in cs_mack will cause them to
801 * execute stage 2, which executes the cs_func(cs_data) and then sets
802 * their bit in cs_mack again.
804 * mack does not include the current cpu.
810 if (cs->cs_func && (cs->cs_mask & gd->gd_cpumask))
811 cs->cs_func(cs->cs_data);
813 DEBUG_PUSH_INFO("cpusync_deinterlock");
815 if (gd->gd_curthread->td_wmesg == NULL)
816 gd->gd_curthread->td_wmesg = smsg;
818 while (cs->cs_mack != mask) {
823 if (gd->gd_curthread->td_wmesg == smsg)
824 gd->gd_curthread->td_wmesg = NULL;
828 * cpusyncq ipis may be left queued without the RQF flag set due to
829 * a non-zero td_cscount, so be sure to process any laggards after
830 * decrementing td_cscount.
832 --gd->gd_curthread->td_cscount;
834 logipiq2(sync_end, (long)mask);
836 crit_exit_id("cpusync");
840 * helper IPI remote messaging function.
842 * Called on remote cpu when a new cpu synchronization request has been
843 * sent to us. Execute the run function and adjust cs_count, then requeue
844 * the request so we spin on it.
847 lwkt_cpusync_remote1(lwkt_cpusync_t cs)
849 globaldata_t gd = mycpu;
851 atomic_set_cpumask(&cs->cs_mack, gd->gd_cpumask);
852 lwkt_cpusync_remote2(cs);
856 * helper IPI remote messaging function.
858 * Poll for the originator telling us to finish. If it hasn't, requeue
859 * our request so we spin on it.
862 lwkt_cpusync_remote2(lwkt_cpusync_t cs)
864 globaldata_t gd = mycpu;
866 if ((cs->cs_mack & gd->gd_cpumask) == 0) {
868 cs->cs_func(cs->cs_data);
869 atomic_set_cpumask(&cs->cs_mack, gd->gd_cpumask);
870 /* cs can be ripped out at this point */
875 ip = &gd->gd_cpusyncq;
876 wi = ip->ip_windex & MAXCPUFIFO_MASK;
877 ip->ip_info[wi].func = (ipifunc3_t)(ipifunc1_t)lwkt_cpusync_remote2;
878 ip->ip_info[wi].arg1 = cs;
879 ip->ip_info[wi].arg2 = 0;
881 KKASSERT(ip->ip_windex - ip->ip_rindex < MAXCPUFIFO);
883 if (ipiq_debug && (ip->ip_windex & 0xFFFFFF) == 0) {
884 kprintf("cpu %d cm=%016jx %016jx f=%p\n",
886 (intmax_t)cs->cs_mask, (intmax_t)cs->cs_mack,