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>
57 #include <vm/vm_param.h>
58 #include <vm/vm_kern.h>
59 #include <vm/vm_object.h>
60 #include <vm/vm_page.h>
61 #include <vm/vm_map.h>
62 #include <vm/vm_pager.h>
63 #include <vm/vm_extern.h>
64 #include <vm/vm_zone.h>
66 #include <machine/stdarg.h>
67 #include <machine/smp.h>
68 #include <machine/atomic.h>
71 static __int64_t ipiq_count; /* total calls to lwkt_send_ipiq*() */
72 static __int64_t ipiq_fifofull; /* number of fifo full conditions detected */
73 static __int64_t ipiq_avoided; /* interlock with target avoids cpu ipi */
74 static __int64_t ipiq_passive; /* passive IPI messages */
75 static __int64_t ipiq_cscount; /* number of cpu synchronizations */
76 static int ipiq_optimized = 1; /* XXX temporary sysctl */
77 static int ipiq_debug; /* set to 1 for debug */
79 static int panic_ipiq_cpu = -1;
80 static int panic_ipiq_count = 100;
85 SYSCTL_QUAD(_lwkt, OID_AUTO, ipiq_count, CTLFLAG_RW, &ipiq_count, 0,
86 "Number of IPI's sent");
87 SYSCTL_QUAD(_lwkt, OID_AUTO, ipiq_fifofull, CTLFLAG_RW, &ipiq_fifofull, 0,
88 "Number of fifo full conditions detected");
89 SYSCTL_QUAD(_lwkt, OID_AUTO, ipiq_avoided, CTLFLAG_RW, &ipiq_avoided, 0,
90 "Number of IPI's avoided by interlock with target cpu");
91 SYSCTL_QUAD(_lwkt, OID_AUTO, ipiq_passive, CTLFLAG_RW, &ipiq_passive, 0,
92 "Number of passive IPI messages sent");
93 SYSCTL_QUAD(_lwkt, OID_AUTO, ipiq_cscount, CTLFLAG_RW, &ipiq_cscount, 0,
94 "Number of cpu synchronizations");
95 SYSCTL_INT(_lwkt, OID_AUTO, ipiq_optimized, CTLFLAG_RW, &ipiq_optimized, 0,
97 SYSCTL_INT(_lwkt, OID_AUTO, ipiq_debug, CTLFLAG_RW, &ipiq_debug, 0,
100 SYSCTL_INT(_lwkt, OID_AUTO, panic_ipiq_cpu, CTLFLAG_RW, &panic_ipiq_cpu, 0, "");
101 SYSCTL_INT(_lwkt, OID_AUTO, panic_ipiq_count, CTLFLAG_RW, &panic_ipiq_count, 0, "");
104 #define IPIQ_STRING "func=%p arg1=%p arg2=%d scpu=%d dcpu=%d"
105 #define IPIQ_ARG_SIZE (sizeof(void *) * 2 + sizeof(int) * 3)
107 #if !defined(KTR_IPIQ)
108 #define KTR_IPIQ KTR_ALL
110 KTR_INFO_MASTER(ipiq);
111 KTR_INFO(KTR_IPIQ, ipiq, send_norm, 0, IPIQ_STRING, IPIQ_ARG_SIZE);
112 KTR_INFO(KTR_IPIQ, ipiq, send_pasv, 1, IPIQ_STRING, IPIQ_ARG_SIZE);
113 KTR_INFO(KTR_IPIQ, ipiq, send_nbio, 2, IPIQ_STRING, IPIQ_ARG_SIZE);
114 KTR_INFO(KTR_IPIQ, ipiq, send_fail, 3, IPIQ_STRING, IPIQ_ARG_SIZE);
115 KTR_INFO(KTR_IPIQ, ipiq, receive, 4, IPIQ_STRING, IPIQ_ARG_SIZE);
116 KTR_INFO(KTR_IPIQ, ipiq, sync_start, 5, "cpumask=%08x", sizeof(cpumask_t));
117 KTR_INFO(KTR_IPIQ, ipiq, sync_end, 6, "cpumask=%08x", sizeof(cpumask_t));
118 KTR_INFO(KTR_IPIQ, ipiq, cpu_send, 7, IPIQ_STRING, IPIQ_ARG_SIZE);
119 KTR_INFO(KTR_IPIQ, ipiq, send_end, 8, IPIQ_STRING, IPIQ_ARG_SIZE);
121 #define logipiq(name, func, arg1, arg2, sgd, dgd) \
122 KTR_LOG(ipiq_ ## name, func, arg1, arg2, sgd->gd_cpuid, dgd->gd_cpuid)
123 #define logipiq2(name, arg) \
124 KTR_LOG(ipiq_ ## name, arg)
130 static int lwkt_process_ipiq_core(globaldata_t sgd, lwkt_ipiq_t ip,
131 struct intrframe *frame);
132 static void lwkt_cpusync_remote1(lwkt_cpusync_t cs);
133 static void lwkt_cpusync_remote2(lwkt_cpusync_t cs);
136 * Send a function execution request to another cpu. The request is queued
137 * on the cpu<->cpu ipiq matrix. Each cpu owns a unique ipiq FIFO for every
138 * possible target cpu. The FIFO can be written.
140 * If the FIFO fills up we have to enable interrupts to avoid an APIC
141 * deadlock and process pending IPIQs while waiting for it to empty.
142 * Otherwise we may soft-deadlock with another cpu whos FIFO is also full.
144 * We can safely bump gd_intr_nesting_level because our crit_exit() at the
145 * end will take care of any pending interrupts.
147 * The actual hardware IPI is avoided if the target cpu is already processing
148 * the queue from a prior IPI. It is possible to pipeline IPI messages
149 * very quickly between cpus due to the FIFO hysteresis.
151 * Need not be called from a critical section.
154 lwkt_send_ipiq3(globaldata_t target, ipifunc3_t func, void *arg1, int arg2)
158 struct globaldata *gd = mycpu;
160 logipiq(send_norm, func, arg1, arg2, gd, target);
163 func(arg1, arg2, NULL);
164 logipiq(send_end, func, arg1, arg2, gd, target);
168 ++gd->gd_intr_nesting_level;
170 if (gd->gd_intr_nesting_level > 20)
171 panic("lwkt_send_ipiq: TOO HEAVILY NESTED!");
173 KKASSERT(curthread->td_critcount);
175 ip = &gd->gd_ipiq[target->gd_cpuid];
178 * Do not allow the FIFO to become full. Interrupts must be physically
179 * enabled while we liveloop to avoid deadlocking the APIC.
181 * The target ipiq may have gotten filled up due to passive IPIs and thus
182 * not be aware that its queue is too full, so be sure to issue an
183 * ipiq interrupt to the target cpu.
185 if (ip->ip_windex - ip->ip_rindex > MAXCPUFIFO / 2) {
186 #if defined(__i386__)
187 unsigned int eflags = read_eflags();
188 #elif defined(__x86_64__)
189 unsigned long rflags = read_rflags();
194 DEBUG_PUSH_INFO("send_ipiq3");
195 while (ip->ip_windex - ip->ip_rindex > MAXCPUFIFO / 4) {
196 if (atomic_poll_acquire_int(&ip->ip_npoll) || ipiq_optimized == 0) {
197 logipiq(cpu_send, func, arg1, arg2, gd, target);
198 cpu_send_ipiq(target->gd_cpuid);
200 KKASSERT(ip->ip_windex - ip->ip_rindex != MAXCPUFIFO - 1);
205 #if defined(__i386__)
206 write_eflags(eflags);
207 #elif defined(__x86_64__)
208 write_rflags(rflags);
213 * Queue the new message
215 windex = ip->ip_windex & MAXCPUFIFO_MASK;
216 ip->ip_func[windex] = func;
217 ip->ip_arg1[windex] = arg1;
218 ip->ip_arg2[windex] = arg2;
223 * signal the target cpu that there is work pending.
225 if (atomic_poll_acquire_int(&ip->ip_npoll) || ipiq_optimized == 0) {
226 logipiq(cpu_send, func, arg1, arg2, gd, target);
227 cpu_send_ipiq(target->gd_cpuid);
231 --gd->gd_intr_nesting_level;
233 logipiq(send_end, func, arg1, arg2, gd, target);
235 return(ip->ip_windex);
239 * Similar to lwkt_send_ipiq() but this function does not actually initiate
240 * the IPI to the target cpu unless the FIFO has become too full, so it is
243 * This function is used for non-critical IPI messages, such as memory
244 * deallocations. The queue will typically be flushed by the target cpu at
245 * the next clock interrupt.
247 * Need not be called from a critical section.
250 lwkt_send_ipiq3_passive(globaldata_t target, ipifunc3_t func,
251 void *arg1, int arg2)
255 struct globaldata *gd = mycpu;
257 KKASSERT(target != gd);
259 ++gd->gd_intr_nesting_level;
260 logipiq(send_pasv, func, arg1, arg2, gd, target);
262 if (gd->gd_intr_nesting_level > 20)
263 panic("lwkt_send_ipiq: TOO HEAVILY NESTED!");
265 KKASSERT(curthread->td_critcount);
268 ip = &gd->gd_ipiq[target->gd_cpuid];
271 * Do not allow the FIFO to become full. Interrupts must be physically
272 * enabled while we liveloop to avoid deadlocking the APIC.
274 if (ip->ip_windex - ip->ip_rindex > MAXCPUFIFO / 2) {
275 #if defined(__i386__)
276 unsigned int eflags = read_eflags();
277 #elif defined(__x86_64__)
278 unsigned long rflags = read_rflags();
283 DEBUG_PUSH_INFO("send_ipiq3_passive");
284 while (ip->ip_windex - ip->ip_rindex > MAXCPUFIFO / 4) {
285 if (atomic_poll_acquire_int(&ip->ip_npoll) || ipiq_optimized == 0) {
286 logipiq(cpu_send, func, arg1, arg2, gd, target);
287 cpu_send_ipiq(target->gd_cpuid);
289 KKASSERT(ip->ip_windex - ip->ip_rindex != MAXCPUFIFO - 1);
294 #if defined(__i386__)
295 write_eflags(eflags);
296 #elif defined(__x86_64__)
297 write_rflags(rflags);
302 * Queue the new message
304 windex = ip->ip_windex & MAXCPUFIFO_MASK;
305 ip->ip_func[windex] = func;
306 ip->ip_arg1[windex] = arg1;
307 ip->ip_arg2[windex] = arg2;
310 --gd->gd_intr_nesting_level;
313 * Do not signal the target cpu, it will pick up the IPI when it next
314 * polls (typically on the next tick).
317 logipiq(send_end, func, arg1, arg2, gd, target);
319 return(ip->ip_windex);
323 * Send an IPI request without blocking, return 0 on success, ENOENT on
324 * failure. The actual queueing of the hardware IPI may still force us
325 * to spin and process incoming IPIs but that will eventually go away
326 * when we've gotten rid of the other general IPIs.
329 lwkt_send_ipiq3_nowait(globaldata_t target, ipifunc3_t func,
330 void *arg1, int arg2)
334 struct globaldata *gd = mycpu;
336 logipiq(send_nbio, func, arg1, arg2, gd, target);
337 KKASSERT(curthread->td_critcount);
339 func(arg1, arg2, NULL);
340 logipiq(send_end, func, arg1, arg2, gd, target);
344 ++gd->gd_intr_nesting_level;
346 ip = &gd->gd_ipiq[target->gd_cpuid];
348 if (ip->ip_windex - ip->ip_rindex >= MAXCPUFIFO * 2 / 3) {
349 logipiq(send_fail, func, arg1, arg2, gd, target);
350 --gd->gd_intr_nesting_level;
354 windex = ip->ip_windex & MAXCPUFIFO_MASK;
355 ip->ip_func[windex] = func;
356 ip->ip_arg1[windex] = arg1;
357 ip->ip_arg2[windex] = arg2;
362 * This isn't a passive IPI, we still have to signal the target cpu.
364 if (atomic_poll_acquire_int(&ip->ip_npoll) || ipiq_optimized == 0) {
365 logipiq(cpu_send, func, arg1, arg2, gd, target);
366 cpu_send_ipiq(target->gd_cpuid);
370 --gd->gd_intr_nesting_level;
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;
490 ++gd->gd_processing_ipiq;
492 for (n = 0; n < ncpus; ++n) {
493 if (n != gd->gd_cpuid) {
494 sgd = globaldata_find(n);
497 while (lwkt_process_ipiq_core(sgd, &ip[gd->gd_cpuid], NULL))
502 if (lwkt_process_ipiq_core(gd, &gd->gd_cpusyncq, NULL)) {
503 if (gd->gd_curthread->td_cscount == 0)
505 /* need_ipiq(); do not reflag */
507 --gd->gd_processing_ipiq;
511 lwkt_process_ipiq_frame(struct intrframe *frame)
513 globaldata_t gd = mycpu;
519 for (n = 0; n < ncpus; ++n) {
520 if (n != gd->gd_cpuid) {
521 sgd = globaldata_find(n);
524 while (lwkt_process_ipiq_core(sgd, &ip[gd->gd_cpuid], frame))
529 if (gd->gd_cpusyncq.ip_rindex != gd->gd_cpusyncq.ip_windex) {
530 if (lwkt_process_ipiq_core(gd, &gd->gd_cpusyncq, frame)) {
531 if (gd->gd_curthread->td_cscount == 0)
533 /* need_ipiq(); do not reflag */
539 static int iqticks[SMP_MAXCPU];
540 static int iqcount[SMP_MAXCPU];
543 static int iqterm[SMP_MAXCPU];
547 lwkt_process_ipiq_core(globaldata_t sgd, lwkt_ipiq_t ip,
548 struct intrframe *frame)
550 globaldata_t mygd = mycpu;
553 ipifunc3_t copy_func;
558 if (iqticks[mygd->gd_cpuid] != ticks) {
559 iqticks[mygd->gd_cpuid] = ticks;
560 iqcount[mygd->gd_cpuid] = 0;
562 if (++iqcount[mygd->gd_cpuid] > 3000000) {
563 kprintf("cpu %d ipiq maxed cscount %d spin %d\n",
565 mygd->gd_curthread->td_cscount,
566 mygd->gd_spinlocks_wr);
567 iqcount[mygd->gd_cpuid] = 0;
569 if (++iqterm[mygd->gd_cpuid] > 10)
570 panic("cpu %d ipiq maxed", mygd->gd_cpuid);
573 for (i = 0; i < ncpus; ++i) {
574 if (globaldata_find(i)->gd_infomsg)
575 kprintf(" %s", globaldata_find(i)->gd_infomsg);
582 * Obtain the current write index, which is modified by a remote cpu.
583 * Issue a load fence to prevent speculative reads of e.g. data written
584 * by the other cpu prior to it updating the index.
586 KKASSERT(curthread->td_critcount);
589 ++mygd->gd_intr_nesting_level;
592 * NOTE: xindex is only updated after we are sure the function has
593 * finished execution. Beware lwkt_process_ipiq() reentrancy!
594 * The function may send an IPI which may block/drain.
596 * NOTE: Due to additional IPI operations that the callback function
597 * may make, it is possible for both rindex and windex to advance and
598 * thus for rindex to advance passed our cached windex.
600 * NOTE: A load fence is required to prevent speculative loads prior
601 * to the loading of ip_rindex. Even though stores might be
602 * ordered, loads are probably not. A memory fence is required
603 * to prevent reordering of the loads after the ip_rindex update.
605 while (wi - (ri = ip->ip_rindex) > 0) {
606 ri &= MAXCPUFIFO_MASK;
608 copy_func = ip->ip_func[ri];
609 copy_arg1 = ip->ip_arg1[ri];
610 copy_arg2 = ip->ip_arg2[ri];
613 KKASSERT((ip->ip_rindex & MAXCPUFIFO_MASK) ==
614 ((ri + 1) & MAXCPUFIFO_MASK));
615 logipiq(receive, copy_func, copy_arg1, copy_arg2, sgd, mycpu);
617 if (ipiq_debug && (ip->ip_rindex & 0xFFFFFF) == 0) {
618 kprintf("cpu %d ipifunc %p %p %d (frame %p)\n",
620 copy_func, copy_arg1, copy_arg2,
621 #if defined(__i386__)
622 (frame ? (void *)frame->if_eip : NULL));
623 #elif defined(__amd64__)
624 (frame ? (void *)frame->if_rip : NULL));
630 copy_func(copy_arg1, copy_arg2, frame);
632 ip->ip_xindex = ip->ip_rindex;
636 * Simulate panics during the processing of an IPI
638 if (mycpu->gd_cpuid == panic_ipiq_cpu && panic_ipiq_count) {
639 if (--panic_ipiq_count == 0) {
641 Debugger("PANIC_DEBUG");
643 panic("PANIC_DEBUG");
649 --mygd->gd_intr_nesting_level;
652 * If the queue is empty release ip_npoll to enable the other cpu to
653 * send us an IPI interrupt again.
655 * Return non-zero if there is still more in the queue. Note that we
656 * must re-check the indexes after potentially releasing ip_npoll. The
657 * caller must loop or otherwise ensure that a loop will occur prior to
660 if (ip->ip_rindex == ip->ip_windex)
661 atomic_poll_release_int(&ip->ip_npoll);
663 return (ip->ip_rindex != ip->ip_windex);
667 lwkt_sync_ipiq(void *arg)
669 volatile cpumask_t *cpumask = arg;
671 atomic_clear_cpumask(cpumask, mycpu->gd_cpumask);
677 lwkt_synchronize_ipiqs(const char *wmesg)
679 volatile cpumask_t other_cpumask;
681 other_cpumask = mycpu->gd_other_cpus & smp_active_mask;
682 lwkt_send_ipiq_mask(other_cpumask, lwkt_sync_ipiq,
683 __DEVOLATILE(void *, &other_cpumask));
685 while (other_cpumask != 0) {
686 tsleep_interlock(&other_cpumask, 0);
687 if (other_cpumask != 0)
688 tsleep(&other_cpumask, PINTERLOCKED, wmesg, 0);
695 * CPU Synchronization Support
697 * lwkt_cpusync_interlock() - Place specified cpus in a quiescent state.
698 * The current cpu is placed in a hard critical
701 * lwkt_cpusync_deinterlock() - Execute cs_func on specified cpus, including
702 * current cpu if specified, then return.
705 lwkt_cpusync_simple(cpumask_t mask, cpusync_func_t func, void *arg)
707 struct lwkt_cpusync cs;
709 lwkt_cpusync_init(&cs, mask, func, arg);
710 lwkt_cpusync_interlock(&cs);
711 lwkt_cpusync_deinterlock(&cs);
716 lwkt_cpusync_interlock(lwkt_cpusync_t cs)
719 globaldata_t gd = mycpu;
723 * mask acknowledge (cs_mack): 0->mask for stage 1
725 * mack does not include the current cpu.
727 mask = cs->cs_mask & gd->gd_other_cpus & smp_active_mask;
729 crit_enter_id("cpusync");
731 DEBUG_PUSH_INFO("cpusync_interlock");
733 ++gd->gd_curthread->td_cscount;
734 lwkt_send_ipiq_mask(mask, (ipifunc1_t)lwkt_cpusync_remote1, cs);
735 logipiq2(sync_start, mask);
736 while (cs->cs_mack != mask) {
748 * Interlocked cpus have executed remote1 and are polling in remote2.
749 * To deinterlock we clear cs_mack and wait for the cpus to execute
750 * the func and set their bit in cs_mack again.
754 lwkt_cpusync_deinterlock(lwkt_cpusync_t cs)
756 globaldata_t gd = mycpu;
761 * mask acknowledge (cs_mack): mack->0->mack for stage 2
763 * Clearing cpu bits for polling cpus in cs_mack will cause them to
764 * execute stage 2, which executes the cs_func(cs_data) and then sets
765 * their bit in cs_mack again.
767 * mack does not include the current cpu.
772 if (cs->cs_func && (cs->cs_mask & gd->gd_cpumask))
773 cs->cs_func(cs->cs_data);
775 DEBUG_PUSH_INFO("cpusync_deinterlock");
776 while (cs->cs_mack != mask) {
782 * cpusyncq ipis may be left queued without the RQF flag set due to
783 * a non-zero td_cscount, so be sure to process any laggards after
784 * decrementing td_cscount.
786 --gd->gd_curthread->td_cscount;
788 logipiq2(sync_end, mask);
790 crit_exit_id("cpusync");
792 if (cs->cs_func && (cs->cs_mask & gd->gd_cpumask))
793 cs->cs_func(cs->cs_data);
800 * helper IPI remote messaging function.
802 * Called on remote cpu when a new cpu synchronization request has been
803 * sent to us. Execute the run function and adjust cs_count, then requeue
804 * the request so we spin on it.
807 lwkt_cpusync_remote1(lwkt_cpusync_t cs)
809 globaldata_t gd = mycpu;
811 atomic_set_cpumask(&cs->cs_mack, gd->gd_cpumask);
812 lwkt_cpusync_remote2(cs);
816 * helper IPI remote messaging function.
818 * Poll for the originator telling us to finish. If it hasn't, requeue
819 * our request so we spin on it.
822 lwkt_cpusync_remote2(lwkt_cpusync_t cs)
824 globaldata_t gd = mycpu;
826 if ((cs->cs_mack & gd->gd_cpumask) == 0) {
828 cs->cs_func(cs->cs_data);
829 atomic_set_cpumask(&cs->cs_mack, gd->gd_cpumask);
834 ip = &gd->gd_cpusyncq;
835 wi = ip->ip_windex & MAXCPUFIFO_MASK;
836 ip->ip_func[wi] = (ipifunc3_t)(ipifunc1_t)lwkt_cpusync_remote2;
837 ip->ip_arg1[wi] = cs;
841 if (ipiq_debug && (ip->ip_windex & 0xFFFFFF) == 0) {
842 kprintf("cpu %d cm=%016jx %016jx f=%p\n",
844 (intmax_t)cs->cs_mask, (intmax_t)cs->cs_mack,