2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
4 * Copyright (c) 2004, 2005,
5 * Bosko Milekic <bmilekic@FreeBSD.org>. All rights reserved.
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
10 * 1. Redistributions of source code must retain the above copyright
11 * notice unmodified, this list of conditions and the following
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 #include <sys/cdefs.h>
31 __FBSDID("$FreeBSD$");
33 #include "opt_param.h"
34 #include "opt_kern_tls.h"
36 #include <sys/param.h>
38 #include <sys/domainset.h>
39 #include <sys/malloc.h>
40 #include <sys/systm.h>
42 #include <sys/domain.h>
43 #include <sys/eventhandler.h>
44 #include <sys/kernel.h>
46 #include <sys/limits.h>
48 #include <sys/mutex.h>
49 #include <sys/protosw.h>
50 #include <sys/refcount.h>
51 #include <sys/sf_buf.h>
53 #include <sys/socket.h>
54 #include <sys/sysctl.h>
57 #include <net/if_var.h>
60 #include <vm/vm_extern.h>
61 #include <vm/vm_kern.h>
62 #include <vm/vm_page.h>
63 #include <vm/vm_map.h>
65 #include <vm/uma_dbg.h>
68 * In FreeBSD, Mbufs and Mbuf Clusters are allocated from UMA
71 * Mbuf Clusters (2K, contiguous) are allocated from the Cluster
72 * Zone. The Zone can be capped at kern.ipc.nmbclusters, if the
73 * administrator so desires.
75 * Mbufs are allocated from a UMA Master Zone called the Mbuf
78 * Additionally, FreeBSD provides a Packet Zone, which it
79 * configures as a Secondary Zone to the Mbuf Master Zone,
80 * thus sharing backend Slab kegs with the Mbuf Master Zone.
82 * Thus common-case allocations and locking are simplified:
86 * | .------------>[(Packet Cache)] m_get(), m_gethdr()
88 * [(Cluster Cache)] [ Secondary ] [ (Mbuf Cache) ]
89 * [ Cluster Zone ] [ Zone ] [ Mbuf Master Zone ]
95 * \____________(VM)_________________/
98 * Whenever an object is allocated with uma_zalloc() out of
99 * one of the Zones its _ctor_ function is executed. The same
100 * for any deallocation through uma_zfree() the _dtor_ function
103 * Caches are per-CPU and are filled from the Master Zone.
105 * Whenever an object is allocated from the underlying global
106 * memory pool it gets pre-initialized with the _zinit_ functions.
107 * When the Keg's are overfull objects get decommissioned with
108 * _zfini_ functions and free'd back to the global memory pool.
112 int nmbufs; /* limits number of mbufs */
113 int nmbclusters; /* limits number of mbuf clusters */
114 int nmbjumbop; /* limits number of page size jumbo clusters */
115 int nmbjumbo9; /* limits number of 9k jumbo clusters */
116 int nmbjumbo16; /* limits number of 16k jumbo clusters */
118 bool mb_use_ext_pgs; /* use EXT_PGS mbufs for sendfile & TLS */
119 SYSCTL_BOOL(_kern_ipc, OID_AUTO, mb_use_ext_pgs, CTLFLAG_RWTUN,
121 "Use unmapped mbufs for sendfile(2) and TLS offload");
123 static quad_t maxmbufmem; /* overall real memory limit for all mbufs */
125 SYSCTL_QUAD(_kern_ipc, OID_AUTO, maxmbufmem, CTLFLAG_RDTUN | CTLFLAG_NOFETCH, &maxmbufmem, 0,
126 "Maximum real memory allocatable to various mbuf types");
128 static counter_u64_t snd_tag_count;
129 SYSCTL_COUNTER_U64(_kern_ipc, OID_AUTO, num_snd_tags, CTLFLAG_RW,
130 &snd_tag_count, "# of active mbuf send tags");
133 * tunable_mbinit() has to be run before any mbuf allocations are done.
136 tunable_mbinit(void *dummy)
141 * The default limit for all mbuf related memory is 1/2 of all
142 * available kernel memory (physical or kmem).
143 * At most it can be 3/4 of available kernel memory.
145 realmem = qmin((quad_t)physmem * PAGE_SIZE, vm_kmem_size);
146 maxmbufmem = realmem / 2;
147 TUNABLE_QUAD_FETCH("kern.ipc.maxmbufmem", &maxmbufmem);
148 if (maxmbufmem > realmem / 4 * 3)
149 maxmbufmem = realmem / 4 * 3;
151 TUNABLE_INT_FETCH("kern.ipc.nmbclusters", &nmbclusters);
152 if (nmbclusters == 0)
153 nmbclusters = maxmbufmem / MCLBYTES / 4;
155 TUNABLE_INT_FETCH("kern.ipc.nmbjumbop", &nmbjumbop);
157 nmbjumbop = maxmbufmem / MJUMPAGESIZE / 4;
159 TUNABLE_INT_FETCH("kern.ipc.nmbjumbo9", &nmbjumbo9);
161 nmbjumbo9 = maxmbufmem / MJUM9BYTES / 6;
163 TUNABLE_INT_FETCH("kern.ipc.nmbjumbo16", &nmbjumbo16);
165 nmbjumbo16 = maxmbufmem / MJUM16BYTES / 6;
168 * We need at least as many mbufs as we have clusters of
169 * the various types added together.
171 TUNABLE_INT_FETCH("kern.ipc.nmbufs", &nmbufs);
172 if (nmbufs < nmbclusters + nmbjumbop + nmbjumbo9 + nmbjumbo16)
173 nmbufs = lmax(maxmbufmem / MSIZE / 5,
174 nmbclusters + nmbjumbop + nmbjumbo9 + nmbjumbo16);
176 SYSINIT(tunable_mbinit, SI_SUB_KMEM, SI_ORDER_MIDDLE, tunable_mbinit, NULL);
179 sysctl_nmbclusters(SYSCTL_HANDLER_ARGS)
181 int error, newnmbclusters;
183 newnmbclusters = nmbclusters;
184 error = sysctl_handle_int(oidp, &newnmbclusters, 0, req);
185 if (error == 0 && req->newptr && newnmbclusters != nmbclusters) {
186 if (newnmbclusters > nmbclusters &&
187 nmbufs >= nmbclusters + nmbjumbop + nmbjumbo9 + nmbjumbo16) {
188 nmbclusters = newnmbclusters;
189 nmbclusters = uma_zone_set_max(zone_clust, nmbclusters);
190 EVENTHANDLER_INVOKE(nmbclusters_change);
196 SYSCTL_PROC(_kern_ipc, OID_AUTO, nmbclusters, CTLTYPE_INT|CTLFLAG_RW,
197 &nmbclusters, 0, sysctl_nmbclusters, "IU",
198 "Maximum number of mbuf clusters allowed");
201 sysctl_nmbjumbop(SYSCTL_HANDLER_ARGS)
203 int error, newnmbjumbop;
205 newnmbjumbop = nmbjumbop;
206 error = sysctl_handle_int(oidp, &newnmbjumbop, 0, req);
207 if (error == 0 && req->newptr && newnmbjumbop != nmbjumbop) {
208 if (newnmbjumbop > nmbjumbop &&
209 nmbufs >= nmbclusters + nmbjumbop + nmbjumbo9 + nmbjumbo16) {
210 nmbjumbop = newnmbjumbop;
211 nmbjumbop = uma_zone_set_max(zone_jumbop, nmbjumbop);
217 SYSCTL_PROC(_kern_ipc, OID_AUTO, nmbjumbop, CTLTYPE_INT|CTLFLAG_RW,
218 &nmbjumbop, 0, sysctl_nmbjumbop, "IU",
219 "Maximum number of mbuf page size jumbo clusters allowed");
222 sysctl_nmbjumbo9(SYSCTL_HANDLER_ARGS)
224 int error, newnmbjumbo9;
226 newnmbjumbo9 = nmbjumbo9;
227 error = sysctl_handle_int(oidp, &newnmbjumbo9, 0, req);
228 if (error == 0 && req->newptr && newnmbjumbo9 != nmbjumbo9) {
229 if (newnmbjumbo9 > nmbjumbo9 &&
230 nmbufs >= nmbclusters + nmbjumbop + nmbjumbo9 + nmbjumbo16) {
231 nmbjumbo9 = newnmbjumbo9;
232 nmbjumbo9 = uma_zone_set_max(zone_jumbo9, nmbjumbo9);
238 SYSCTL_PROC(_kern_ipc, OID_AUTO, nmbjumbo9, CTLTYPE_INT|CTLFLAG_RW,
239 &nmbjumbo9, 0, sysctl_nmbjumbo9, "IU",
240 "Maximum number of mbuf 9k jumbo clusters allowed");
243 sysctl_nmbjumbo16(SYSCTL_HANDLER_ARGS)
245 int error, newnmbjumbo16;
247 newnmbjumbo16 = nmbjumbo16;
248 error = sysctl_handle_int(oidp, &newnmbjumbo16, 0, req);
249 if (error == 0 && req->newptr && newnmbjumbo16 != nmbjumbo16) {
250 if (newnmbjumbo16 > nmbjumbo16 &&
251 nmbufs >= nmbclusters + nmbjumbop + nmbjumbo9 + nmbjumbo16) {
252 nmbjumbo16 = newnmbjumbo16;
253 nmbjumbo16 = uma_zone_set_max(zone_jumbo16, nmbjumbo16);
259 SYSCTL_PROC(_kern_ipc, OID_AUTO, nmbjumbo16, CTLTYPE_INT|CTLFLAG_RW,
260 &nmbjumbo16, 0, sysctl_nmbjumbo16, "IU",
261 "Maximum number of mbuf 16k jumbo clusters allowed");
264 sysctl_nmbufs(SYSCTL_HANDLER_ARGS)
266 int error, newnmbufs;
269 error = sysctl_handle_int(oidp, &newnmbufs, 0, req);
270 if (error == 0 && req->newptr && newnmbufs != nmbufs) {
271 if (newnmbufs > nmbufs) {
273 nmbufs = uma_zone_set_max(zone_mbuf, nmbufs);
274 EVENTHANDLER_INVOKE(nmbufs_change);
280 SYSCTL_PROC(_kern_ipc, OID_AUTO, nmbufs, CTLTYPE_INT|CTLFLAG_RW,
281 &nmbufs, 0, sysctl_nmbufs, "IU",
282 "Maximum number of mbufs allowed");
285 * Zones from which we allocate.
287 uma_zone_t zone_mbuf;
288 uma_zone_t zone_clust;
289 uma_zone_t zone_pack;
290 uma_zone_t zone_jumbop;
291 uma_zone_t zone_jumbo9;
292 uma_zone_t zone_jumbo16;
293 uma_zone_t zone_extpgs;
298 static int mb_ctor_mbuf(void *, int, void *, int);
299 static int mb_ctor_clust(void *, int, void *, int);
300 static int mb_ctor_pack(void *, int, void *, int);
301 static void mb_dtor_mbuf(void *, int, void *);
302 static void mb_dtor_pack(void *, int, void *);
303 static int mb_zinit_pack(void *, int, int);
304 static void mb_zfini_pack(void *, int);
305 static void mb_reclaim(uma_zone_t, int);
306 static void *mbuf_jumbo_alloc(uma_zone_t, vm_size_t, int, uint8_t *, int);
308 /* Ensure that MSIZE is a power of 2. */
309 CTASSERT((((MSIZE - 1) ^ MSIZE) + 1) >> 1 == MSIZE);
311 _Static_assert(sizeof(struct mbuf_ext_pgs) == 256,
312 "mbuf_ext_pgs size mismatch");
315 * Initialize FreeBSD Network buffer allocation.
318 mbuf_init(void *dummy)
322 * Configure UMA zones for Mbufs, Clusters, and Packets.
324 zone_mbuf = uma_zcreate(MBUF_MEM_NAME, MSIZE,
325 mb_ctor_mbuf, mb_dtor_mbuf, NULL, NULL,
326 MSIZE - 1, UMA_ZONE_MAXBUCKET);
328 nmbufs = uma_zone_set_max(zone_mbuf, nmbufs);
329 uma_zone_set_warning(zone_mbuf, "kern.ipc.nmbufs limit reached");
330 uma_zone_set_maxaction(zone_mbuf, mb_reclaim);
332 zone_clust = uma_zcreate(MBUF_CLUSTER_MEM_NAME, MCLBYTES,
333 mb_ctor_clust, NULL, NULL, NULL,
336 nmbclusters = uma_zone_set_max(zone_clust, nmbclusters);
337 uma_zone_set_warning(zone_clust, "kern.ipc.nmbclusters limit reached");
338 uma_zone_set_maxaction(zone_clust, mb_reclaim);
340 zone_pack = uma_zsecond_create(MBUF_PACKET_MEM_NAME, mb_ctor_pack,
341 mb_dtor_pack, mb_zinit_pack, mb_zfini_pack, zone_mbuf);
343 /* Make jumbo frame zone too. Page size, 9k and 16k. */
344 zone_jumbop = uma_zcreate(MBUF_JUMBOP_MEM_NAME, MJUMPAGESIZE,
345 mb_ctor_clust, NULL, NULL, NULL,
348 nmbjumbop = uma_zone_set_max(zone_jumbop, nmbjumbop);
349 uma_zone_set_warning(zone_jumbop, "kern.ipc.nmbjumbop limit reached");
350 uma_zone_set_maxaction(zone_jumbop, mb_reclaim);
352 zone_jumbo9 = uma_zcreate(MBUF_JUMBO9_MEM_NAME, MJUM9BYTES,
353 mb_ctor_clust, NULL, NULL, NULL,
355 uma_zone_set_allocf(zone_jumbo9, mbuf_jumbo_alloc);
357 nmbjumbo9 = uma_zone_set_max(zone_jumbo9, nmbjumbo9);
358 uma_zone_set_warning(zone_jumbo9, "kern.ipc.nmbjumbo9 limit reached");
359 uma_zone_set_maxaction(zone_jumbo9, mb_reclaim);
361 zone_jumbo16 = uma_zcreate(MBUF_JUMBO16_MEM_NAME, MJUM16BYTES,
362 mb_ctor_clust, NULL, NULL, NULL,
364 uma_zone_set_allocf(zone_jumbo16, mbuf_jumbo_alloc);
366 nmbjumbo16 = uma_zone_set_max(zone_jumbo16, nmbjumbo16);
367 uma_zone_set_warning(zone_jumbo16, "kern.ipc.nmbjumbo16 limit reached");
368 uma_zone_set_maxaction(zone_jumbo16, mb_reclaim);
370 zone_extpgs = uma_zcreate(MBUF_EXTPGS_MEM_NAME,
371 sizeof(struct mbuf_ext_pgs),
372 NULL, NULL, NULL, NULL,
376 * Hook event handler for low-memory situation, used to
377 * drain protocols and push data back to the caches (UMA
378 * later pushes it back to VM).
380 EVENTHANDLER_REGISTER(vm_lowmem, mb_reclaim, NULL,
381 EVENTHANDLER_PRI_FIRST);
383 snd_tag_count = counter_u64_alloc(M_WAITOK);
385 SYSINIT(mbuf, SI_SUB_MBUF, SI_ORDER_FIRST, mbuf_init, NULL);
389 * debugnet makes use of a pre-allocated pool of mbufs and clusters. When
390 * debugnet is configured, we initialize a set of UMA cache zones which return
391 * items from this pool. At panic-time, the regular UMA zone pointers are
392 * overwritten with those of the cache zones so that drivers may allocate and
393 * free mbufs and clusters without attempting to allocate physical memory.
395 * We keep mbufs and clusters in a pair of mbuf queues. In particular, for
396 * the purpose of caching clusters, we treat them as mbufs.
398 static struct mbufq dn_mbufq =
399 { STAILQ_HEAD_INITIALIZER(dn_mbufq.mq_head), 0, INT_MAX };
400 static struct mbufq dn_clustq =
401 { STAILQ_HEAD_INITIALIZER(dn_clustq.mq_head), 0, INT_MAX };
403 static int dn_clsize;
404 static uma_zone_t dn_zone_mbuf;
405 static uma_zone_t dn_zone_clust;
406 static uma_zone_t dn_zone_pack;
408 static struct debugnet_saved_zones {
410 uma_zone_t dsz_clust;
412 uma_zone_t dsz_jumbop;
413 uma_zone_t dsz_jumbo9;
414 uma_zone_t dsz_jumbo16;
415 bool dsz_debugnet_zones_enabled;
419 dn_buf_import(void *arg, void **store, int count, int domain __unused,
428 for (i = 0; i < count; i++) {
429 m = mbufq_dequeue(q);
432 trash_init(m, q == &dn_mbufq ? MSIZE : dn_clsize, flags);
435 KASSERT((flags & M_WAITOK) == 0 || i == count,
436 ("%s: ran out of pre-allocated mbufs", __func__));
441 dn_buf_release(void *arg, void **store, int count)
449 for (i = 0; i < count; i++) {
451 (void)mbufq_enqueue(q, m);
456 dn_pack_import(void *arg __unused, void **store, int count, int domain __unused,
463 for (i = 0; i < count; i++) {
464 m = m_get(MT_DATA, M_NOWAIT);
467 clust = uma_zalloc(dn_zone_clust, M_NOWAIT);
472 mb_ctor_clust(clust, dn_clsize, m, 0);
475 KASSERT((flags & M_WAITOK) == 0 || i == count,
476 ("%s: ran out of pre-allocated mbufs", __func__));
481 dn_pack_release(void *arg __unused, void **store, int count)
487 for (i = 0; i < count; i++) {
489 clust = m->m_ext.ext_buf;
490 uma_zfree(dn_zone_clust, clust);
491 uma_zfree(dn_zone_mbuf, m);
496 * Free the pre-allocated mbufs and clusters reserved for debugnet, and destroy
497 * the corresponding UMA cache zones.
500 debugnet_mbuf_drain(void)
505 if (dn_zone_mbuf != NULL) {
506 uma_zdestroy(dn_zone_mbuf);
509 if (dn_zone_clust != NULL) {
510 uma_zdestroy(dn_zone_clust);
511 dn_zone_clust = NULL;
513 if (dn_zone_pack != NULL) {
514 uma_zdestroy(dn_zone_pack);
518 while ((m = mbufq_dequeue(&dn_mbufq)) != NULL)
520 while ((item = mbufq_dequeue(&dn_clustq)) != NULL)
521 uma_zfree(m_getzone(dn_clsize), item);
525 * Callback invoked immediately prior to starting a debugnet connection.
528 debugnet_mbuf_start(void)
531 MPASS(!dn_saved_zones.dsz_debugnet_zones_enabled);
533 /* Save the old zone pointers to restore when debugnet is closed. */
534 dn_saved_zones = (struct debugnet_saved_zones) {
535 .dsz_debugnet_zones_enabled = true,
536 .dsz_mbuf = zone_mbuf,
537 .dsz_clust = zone_clust,
538 .dsz_pack = zone_pack,
539 .dsz_jumbop = zone_jumbop,
540 .dsz_jumbo9 = zone_jumbo9,
541 .dsz_jumbo16 = zone_jumbo16,
545 * All cluster zones return buffers of the size requested by the
546 * drivers. It's up to the driver to reinitialize the zones if the
547 * MTU of a debugnet-enabled interface changes.
549 printf("debugnet: overwriting mbuf zone pointers\n");
550 zone_mbuf = dn_zone_mbuf;
551 zone_clust = dn_zone_clust;
552 zone_pack = dn_zone_pack;
553 zone_jumbop = dn_zone_clust;
554 zone_jumbo9 = dn_zone_clust;
555 zone_jumbo16 = dn_zone_clust;
559 * Callback invoked when a debugnet connection is closed/finished.
562 debugnet_mbuf_finish(void)
565 MPASS(dn_saved_zones.dsz_debugnet_zones_enabled);
567 printf("debugnet: restoring mbuf zone pointers\n");
568 zone_mbuf = dn_saved_zones.dsz_mbuf;
569 zone_clust = dn_saved_zones.dsz_clust;
570 zone_pack = dn_saved_zones.dsz_pack;
571 zone_jumbop = dn_saved_zones.dsz_jumbop;
572 zone_jumbo9 = dn_saved_zones.dsz_jumbo9;
573 zone_jumbo16 = dn_saved_zones.dsz_jumbo16;
575 memset(&dn_saved_zones, 0, sizeof(dn_saved_zones));
579 * Reinitialize the debugnet mbuf+cluster pool and cache zones.
582 debugnet_mbuf_reinit(int nmbuf, int nclust, int clsize)
587 debugnet_mbuf_drain();
591 dn_zone_mbuf = uma_zcache_create("debugnet_" MBUF_MEM_NAME,
592 MSIZE, mb_ctor_mbuf, mb_dtor_mbuf, NULL, NULL,
593 dn_buf_import, dn_buf_release,
594 &dn_mbufq, UMA_ZONE_NOBUCKET);
596 dn_zone_clust = uma_zcache_create("debugnet_" MBUF_CLUSTER_MEM_NAME,
597 clsize, mb_ctor_clust, NULL, NULL, NULL,
598 dn_buf_import, dn_buf_release,
599 &dn_clustq, UMA_ZONE_NOBUCKET);
601 dn_zone_pack = uma_zcache_create("debugnet_" MBUF_PACKET_MEM_NAME,
602 MCLBYTES, mb_ctor_pack, mb_dtor_pack, NULL, NULL,
603 dn_pack_import, dn_pack_release,
604 NULL, UMA_ZONE_NOBUCKET);
606 while (nmbuf-- > 0) {
607 m = m_get(MT_DATA, M_WAITOK);
608 uma_zfree(dn_zone_mbuf, m);
610 while (nclust-- > 0) {
611 item = uma_zalloc(m_getzone(dn_clsize), M_WAITOK);
612 uma_zfree(dn_zone_clust, item);
615 #endif /* DEBUGNET */
618 * UMA backend page allocator for the jumbo frame zones.
620 * Allocates kernel virtual memory that is backed by contiguous physical
624 mbuf_jumbo_alloc(uma_zone_t zone, vm_size_t bytes, int domain, uint8_t *flags,
628 /* Inform UMA that this allocator uses kernel_map/object. */
629 *flags = UMA_SLAB_KERNEL;
630 return ((void *)kmem_alloc_contig_domainset(DOMAINSET_FIXED(domain),
631 bytes, wait, (vm_paddr_t)0, ~(vm_paddr_t)0, 1, 0,
632 VM_MEMATTR_DEFAULT));
636 * Constructor for Mbuf master zone.
638 * The 'arg' pointer points to a mb_args structure which
639 * contains call-specific information required to support the
640 * mbuf allocation API. See mbuf.h.
643 mb_ctor_mbuf(void *mem, int size, void *arg, int how)
646 struct mb_args *args;
651 args = (struct mb_args *)arg;
655 * The mbuf is initialized later. The caller has the
656 * responsibility to set up any MAC labels too.
658 if (type == MT_NOINIT)
661 m = (struct mbuf *)mem;
663 MPASS((flags & M_NOFREE) == 0);
665 error = m_init(m, how, type, flags);
671 * The Mbuf master zone destructor.
674 mb_dtor_mbuf(void *mem, int size, void *arg)
679 m = (struct mbuf *)mem;
680 flags = (unsigned long)arg;
682 KASSERT((m->m_flags & M_NOFREE) == 0, ("%s: M_NOFREE set", __func__));
683 if (!(flags & MB_DTOR_SKIP) && (m->m_flags & M_PKTHDR) && !SLIST_EMPTY(&m->m_pkthdr.tags))
684 m_tag_delete_chain(m, NULL);
688 * The Mbuf Packet zone destructor.
691 mb_dtor_pack(void *mem, int size, void *arg)
695 m = (struct mbuf *)mem;
696 if ((m->m_flags & M_PKTHDR) != 0)
697 m_tag_delete_chain(m, NULL);
699 /* Make sure we've got a clean cluster back. */
700 KASSERT((m->m_flags & M_EXT) == M_EXT, ("%s: M_EXT not set", __func__));
701 KASSERT(m->m_ext.ext_buf != NULL, ("%s: ext_buf == NULL", __func__));
702 KASSERT(m->m_ext.ext_free == NULL, ("%s: ext_free != NULL", __func__));
703 KASSERT(m->m_ext.ext_arg1 == NULL, ("%s: ext_arg1 != NULL", __func__));
704 KASSERT(m->m_ext.ext_arg2 == NULL, ("%s: ext_arg2 != NULL", __func__));
705 KASSERT(m->m_ext.ext_size == MCLBYTES, ("%s: ext_size != MCLBYTES", __func__));
706 KASSERT(m->m_ext.ext_type == EXT_PACKET, ("%s: ext_type != EXT_PACKET", __func__));
708 trash_dtor(m->m_ext.ext_buf, MCLBYTES, arg);
711 * If there are processes blocked on zone_clust, waiting for pages
712 * to be freed up, cause them to be woken up by draining the
713 * packet zone. We are exposed to a race here (in the check for
714 * the UMA_ZFLAG_FULL) where we might miss the flag set, but that
715 * is deliberate. We don't want to acquire the zone lock for every
718 if (uma_zone_exhausted_nolock(zone_clust))
719 uma_zone_reclaim(zone_pack, UMA_RECLAIM_DRAIN);
723 * The Cluster and Jumbo[PAGESIZE|9|16] zone constructor.
725 * Here the 'arg' pointer points to the Mbuf which we
726 * are configuring cluster storage for. If 'arg' is
727 * empty we allocate just the cluster without setting
728 * the mbuf to it. See mbuf.h.
731 mb_ctor_clust(void *mem, int size, void *arg, int how)
735 m = (struct mbuf *)arg;
737 m->m_ext.ext_buf = (char *)mem;
738 m->m_data = m->m_ext.ext_buf;
740 m->m_ext.ext_free = NULL;
741 m->m_ext.ext_arg1 = NULL;
742 m->m_ext.ext_arg2 = NULL;
743 m->m_ext.ext_size = size;
744 m->m_ext.ext_type = m_gettype(size);
745 m->m_ext.ext_flags = EXT_FLAG_EMBREF;
746 m->m_ext.ext_count = 1;
753 * The Packet secondary zone's init routine, executed on the
754 * object's transition from mbuf keg slab to zone cache.
757 mb_zinit_pack(void *mem, int size, int how)
761 m = (struct mbuf *)mem; /* m is virgin. */
762 if (uma_zalloc_arg(zone_clust, m, how) == NULL ||
763 m->m_ext.ext_buf == NULL)
765 m->m_ext.ext_type = EXT_PACKET; /* Override. */
767 trash_init(m->m_ext.ext_buf, MCLBYTES, how);
773 * The Packet secondary zone's fini routine, executed on the
774 * object's transition from zone cache to keg slab.
777 mb_zfini_pack(void *mem, int size)
781 m = (struct mbuf *)mem;
783 trash_fini(m->m_ext.ext_buf, MCLBYTES);
785 uma_zfree_arg(zone_clust, m->m_ext.ext_buf, NULL);
787 trash_dtor(mem, size, NULL);
792 * The "packet" keg constructor.
795 mb_ctor_pack(void *mem, int size, void *arg, int how)
798 struct mb_args *args;
802 m = (struct mbuf *)mem;
803 args = (struct mb_args *)arg;
806 MPASS((flags & M_NOFREE) == 0);
809 trash_ctor(m->m_ext.ext_buf, MCLBYTES, arg, how);
812 error = m_init(m, how, type, flags);
814 /* m_ext is already initialized. */
815 m->m_data = m->m_ext.ext_buf;
816 m->m_flags = (flags | M_EXT);
822 * This is the protocol drain routine. Called by UMA whenever any of the
823 * mbuf zones is closed to its limit.
825 * No locks should be held when this is called. The drain routines have to
826 * presently acquire some locks which raises the possibility of lock order
830 mb_reclaim(uma_zone_t zone __unused, int pending __unused)
835 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK | WARN_PANIC, NULL, __func__);
837 for (dp = domains; dp != NULL; dp = dp->dom_next)
838 for (pr = dp->dom_protosw; pr < dp->dom_protoswNPROTOSW; pr++)
839 if (pr->pr_drain != NULL)
844 * Free "count" units of I/O from an mbuf chain. They could be held
845 * in EXT_PGS or just as a normal mbuf. This code is intended to be
846 * called in an error path (I/O error, closed connection, etc).
849 mb_free_notready(struct mbuf *m, int count)
853 for (i = 0; i < count && m != NULL; i++) {
854 if ((m->m_flags & M_EXT) != 0 &&
855 m->m_ext.ext_type == EXT_PGS) {
856 m->m_ext.ext_pgs->nrdy--;
857 if (m->m_ext.ext_pgs->nrdy != 0)
862 KASSERT(i == count, ("Removed only %d items from %p", i, m));
866 * Compress an unmapped mbuf into a simple mbuf when it holds a small
867 * amount of data. This is used as a DOS defense to avoid having
868 * small packets tie up wired pages, an ext_pgs structure, and an
869 * mbuf. Since this converts the existing mbuf in place, it can only
870 * be used if there are no other references to 'm'.
873 mb_unmapped_compress(struct mbuf *m)
875 volatile u_int *refcnt;
879 * Assert that 'm' does not have a packet header. If 'm' had
880 * a packet header, it would only be able to hold MHLEN bytes
881 * and m_data would have to be initialized differently.
883 KASSERT((m->m_flags & M_PKTHDR) == 0 && (m->m_flags & M_EXT) &&
884 m->m_ext.ext_type == EXT_PGS,
885 ("%s: m %p !M_EXT or !EXT_PGS or M_PKTHDR", __func__, m));
886 KASSERT(m->m_len <= MLEN, ("m_len too large %p", m));
888 if (m->m_ext.ext_flags & EXT_FLAG_EMBREF) {
889 refcnt = &m->m_ext.ext_count;
891 KASSERT(m->m_ext.ext_cnt != NULL,
892 ("%s: no refcounting pointer on %p", __func__, m));
893 refcnt = m->m_ext.ext_cnt;
900 * Copy mbuf header and m_ext portion of 'm' to 'm_temp' to
901 * create a "fake" EXT_PGS mbuf that can be used with
902 * m_copydata() as well as the ext_free callback.
904 memcpy(&m_temp, m, offsetof(struct mbuf, m_ext) + sizeof (m->m_ext));
905 m_temp.m_next = NULL;
906 m_temp.m_nextpkt = NULL;
908 /* Turn 'm' into a "normal" mbuf. */
909 m->m_flags &= ~(M_EXT | M_RDONLY | M_NOMAP);
910 m->m_data = m->m_dat;
912 /* Copy data from template's ext_pgs. */
913 m_copydata(&m_temp, 0, m_temp.m_len, mtod(m, caddr_t));
915 /* Free the backing pages. */
916 m_temp.m_ext.ext_free(&m_temp);
918 /* Finally, free the ext_pgs struct. */
919 uma_zfree(zone_extpgs, m_temp.m_ext.ext_pgs);
924 * These next few routines are used to permit downgrading an unmapped
925 * mbuf to a chain of mapped mbufs. This is used when an interface
926 * doesn't supported unmapped mbufs or if checksums need to be
927 * computed in software.
929 * Each unmapped mbuf is converted to a chain of mbufs. First, any
930 * TLS header data is stored in a regular mbuf. Second, each page of
931 * unmapped data is stored in an mbuf with an EXT_SFBUF external
932 * cluster. These mbufs use an sf_buf to provide a valid KVA for the
933 * associated physical page. They also hold a reference on the
934 * original EXT_PGS mbuf to ensure the physical page doesn't go away.
935 * Finally, any TLS trailer data is stored in a regular mbuf.
937 * mb_unmapped_free_mext() is the ext_free handler for the EXT_SFBUF
938 * mbufs. It frees the associated sf_buf and releases its reference
939 * on the original EXT_PGS mbuf.
941 * _mb_unmapped_to_ext() is a helper function that converts a single
942 * unmapped mbuf into a chain of mbufs.
944 * mb_unmapped_to_ext() is the public function that walks an mbuf
945 * chain converting any unmapped mbufs to mapped mbufs. It returns
946 * the new chain of unmapped mbufs on success. On failure it frees
947 * the original mbuf chain and returns NULL.
950 mb_unmapped_free_mext(struct mbuf *m)
955 sf = m->m_ext.ext_arg1;
958 /* Drop the reference on the backing EXT_PGS mbuf. */
959 old_m = m->m_ext.ext_arg2;
964 _mb_unmapped_to_ext(struct mbuf *m)
966 struct mbuf_ext_pgs *ext_pgs;
967 struct mbuf *m_new, *top, *prev, *mref;
970 int i, len, off, pglen, pgoff, seglen, segoff;
971 volatile u_int *refcnt;
974 MBUF_EXT_PGS_ASSERT(m);
975 ext_pgs = m->m_ext.ext_pgs;
977 KASSERT(ext_pgs->tls == NULL, ("%s: can't convert TLS mbuf %p",
980 /* See if this is the mbuf that holds the embedded refcount. */
981 if (m->m_ext.ext_flags & EXT_FLAG_EMBREF) {
982 refcnt = &m->m_ext.ext_count;
985 KASSERT(m->m_ext.ext_cnt != NULL,
986 ("%s: no refcounting pointer on %p", __func__, m));
987 refcnt = m->m_ext.ext_cnt;
988 mref = __containerof(refcnt, struct mbuf, m_ext.ext_count);
991 /* Skip over any data removed from the front. */
992 off = mtod(m, vm_offset_t);
995 if (ext_pgs->hdr_len != 0) {
996 if (off >= ext_pgs->hdr_len) {
997 off -= ext_pgs->hdr_len;
999 seglen = ext_pgs->hdr_len - off;
1001 seglen = min(seglen, len);
1004 m_new = m_get(M_NOWAIT, MT_DATA);
1007 m_new->m_len = seglen;
1009 memcpy(mtod(m_new, void *), &ext_pgs->hdr[segoff],
1013 pgoff = ext_pgs->first_pg_off;
1014 for (i = 0; i < ext_pgs->npgs && len > 0; i++) {
1015 pglen = mbuf_ext_pg_len(ext_pgs, i, pgoff);
1021 seglen = pglen - off;
1022 segoff = pgoff + off;
1024 seglen = min(seglen, len);
1027 pg = PHYS_TO_VM_PAGE(ext_pgs->pa[i]);
1028 m_new = m_get(M_NOWAIT, MT_DATA);
1034 prev->m_next = m_new;
1037 sf = sf_buf_alloc(pg, SFB_NOWAIT);
1042 m_extadd(m_new, (char *)sf_buf_kva(sf), PAGE_SIZE,
1043 mb_unmapped_free_mext, sf, mref, M_RDONLY, EXT_SFBUF);
1044 m_new->m_data += segoff;
1045 m_new->m_len = seglen;
1050 KASSERT((off + len) <= ext_pgs->trail_len,
1051 ("off + len > trail (%d + %d > %d)", off, len,
1052 ext_pgs->trail_len));
1053 m_new = m_get(M_NOWAIT, MT_DATA);
1059 prev->m_next = m_new;
1061 memcpy(mtod(m_new, void *), &ext_pgs->trail[off], len);
1066 * Obtain an additional reference on the old mbuf for
1067 * each created EXT_SFBUF mbuf. They will be dropped
1068 * in mb_unmapped_free_mext().
1073 atomic_add_int(refcnt, ref_inc);
1081 * Obtain an additional reference on the old mbuf for
1082 * each created EXT_SFBUF mbuf. They will be
1083 * immediately dropped when these mbufs are freed
1089 atomic_add_int(refcnt, ref_inc);
1097 mb_unmapped_to_ext(struct mbuf *top)
1099 struct mbuf *m, *next, *prev = NULL;
1102 for (m = top; m != NULL; m = next) {
1103 /* m might be freed, so cache the next pointer. */
1105 if (m->m_flags & M_NOMAP) {
1108 * Remove 'm' from the new chain so
1109 * that the 'top' chain terminates
1110 * before 'm' in case 'top' is freed
1113 prev->m_next = NULL;
1115 m = _mb_unmapped_to_ext(m);
1128 * Replaced one mbuf with a chain, so we must
1129 * find the end of chain.
1143 * Allocate an empty EXT_PGS mbuf. The ext_free routine is
1144 * responsible for freeing any pages backing this mbuf when it is
1148 mb_alloc_ext_pgs(int how, bool pkthdr, m_ext_free_t ext_free)
1151 struct mbuf_ext_pgs *ext_pgs;
1154 m = m_gethdr(how, MT_DATA);
1156 m = m_get(how, MT_DATA);
1160 ext_pgs = uma_zalloc(zone_extpgs, how);
1161 if (ext_pgs == NULL) {
1167 ext_pgs->first_pg_off = 0;
1168 ext_pgs->last_pg_len = 0;
1170 ext_pgs->hdr_len = 0;
1171 ext_pgs->trail_len = 0;
1172 ext_pgs->tls = NULL;
1175 m->m_flags |= (M_EXT | M_RDONLY | M_NOMAP);
1176 m->m_ext.ext_type = EXT_PGS;
1177 m->m_ext.ext_flags = EXT_FLAG_EMBREF;
1178 m->m_ext.ext_count = 1;
1179 m->m_ext.ext_pgs = ext_pgs;
1180 m->m_ext.ext_size = 0;
1181 m->m_ext.ext_free = ext_free;
1185 #ifdef INVARIANT_SUPPORT
1187 mb_ext_pgs_check(struct mbuf_ext_pgs *ext_pgs)
1191 * NB: This expects a non-empty buffer (npgs > 0 and
1194 KASSERT(ext_pgs->npgs > 0,
1195 ("ext_pgs with no valid pages: %p", ext_pgs));
1196 KASSERT(ext_pgs->npgs <= nitems(ext_pgs->pa),
1197 ("ext_pgs with too many pages: %p", ext_pgs));
1198 KASSERT(ext_pgs->nrdy <= ext_pgs->npgs,
1199 ("ext_pgs with too many ready pages: %p", ext_pgs));
1200 KASSERT(ext_pgs->first_pg_off < PAGE_SIZE,
1201 ("ext_pgs with too large page offset: %p", ext_pgs));
1202 KASSERT(ext_pgs->last_pg_len > 0,
1203 ("ext_pgs with zero last page length: %p", ext_pgs));
1204 KASSERT(ext_pgs->last_pg_len <= PAGE_SIZE,
1205 ("ext_pgs with too large last page length: %p", ext_pgs));
1206 if (ext_pgs->npgs == 1) {
1207 KASSERT(ext_pgs->first_pg_off + ext_pgs->last_pg_len <=
1208 PAGE_SIZE, ("ext_pgs with single page too large: %p",
1211 KASSERT(ext_pgs->hdr_len <= sizeof(ext_pgs->hdr),
1212 ("ext_pgs with too large header length: %p", ext_pgs));
1213 KASSERT(ext_pgs->trail_len <= sizeof(ext_pgs->trail),
1214 ("ext_pgs with too large header length: %p", ext_pgs));
1219 * Clean up after mbufs with M_EXT storage attached to them if the
1220 * reference count hits 1.
1223 mb_free_ext(struct mbuf *m)
1225 volatile u_int *refcnt;
1229 KASSERT(m->m_flags & M_EXT, ("%s: M_EXT not set on %p", __func__, m));
1231 /* See if this is the mbuf that holds the embedded refcount. */
1232 if (m->m_ext.ext_flags & EXT_FLAG_EMBREF) {
1233 refcnt = &m->m_ext.ext_count;
1236 KASSERT(m->m_ext.ext_cnt != NULL,
1237 ("%s: no refcounting pointer on %p", __func__, m));
1238 refcnt = m->m_ext.ext_cnt;
1239 mref = __containerof(refcnt, struct mbuf, m_ext.ext_count);
1243 * Check if the header is embedded in the cluster. It is
1244 * important that we can't touch any of the mbuf fields
1245 * after we have freed the external storage, since mbuf
1246 * could have been embedded in it. For now, the mbufs
1247 * embedded into the cluster are always of type EXT_EXTREF,
1248 * and for this type we won't free the mref.
1250 if (m->m_flags & M_NOFREE) {
1252 KASSERT(m->m_ext.ext_type == EXT_EXTREF ||
1253 m->m_ext.ext_type == EXT_RXRING,
1254 ("%s: no-free mbuf %p has wrong type", __func__, m));
1258 /* Free attached storage if this mbuf is the only reference to it. */
1259 if (*refcnt == 1 || atomic_fetchadd_int(refcnt, -1) == 1) {
1260 switch (m->m_ext.ext_type) {
1262 /* The packet zone is special. */
1265 uma_zfree(zone_pack, mref);
1268 uma_zfree(zone_clust, m->m_ext.ext_buf);
1269 uma_zfree(zone_mbuf, mref);
1272 uma_zfree(zone_jumbop, m->m_ext.ext_buf);
1273 uma_zfree(zone_mbuf, mref);
1276 uma_zfree(zone_jumbo9, m->m_ext.ext_buf);
1277 uma_zfree(zone_mbuf, mref);
1280 uma_zfree(zone_jumbo16, m->m_ext.ext_buf);
1281 uma_zfree(zone_mbuf, mref);
1285 struct mbuf_ext_pgs *pgs;
1286 struct ktls_session *tls;
1289 KASSERT(mref->m_ext.ext_free != NULL,
1290 ("%s: ext_free not set", __func__));
1291 mref->m_ext.ext_free(mref);
1293 pgs = mref->m_ext.ext_pgs;
1296 !refcount_release_if_not_last(&tls->refcount))
1297 ktls_enqueue_to_free(pgs);
1300 uma_zfree(zone_extpgs, mref->m_ext.ext_pgs);
1301 uma_zfree(zone_mbuf, mref);
1307 case EXT_DISPOSABLE:
1308 KASSERT(mref->m_ext.ext_free != NULL,
1309 ("%s: ext_free not set", __func__));
1310 mref->m_ext.ext_free(mref);
1311 uma_zfree(zone_mbuf, mref);
1314 KASSERT(m->m_ext.ext_free != NULL,
1315 ("%s: ext_free not set", __func__));
1316 m->m_ext.ext_free(m);
1319 KASSERT(m->m_ext.ext_free == NULL,
1320 ("%s: ext_free is set", __func__));
1323 KASSERT(m->m_ext.ext_type == 0,
1324 ("%s: unknown ext_type", __func__));
1328 if (freembuf && m != mref)
1329 uma_zfree(zone_mbuf, m);
1333 * Official mbuf(9) allocation KPI for stack and drivers:
1335 * m_get() - a single mbuf without any attachments, sys/mbuf.h.
1336 * m_gethdr() - a single mbuf initialized as M_PKTHDR, sys/mbuf.h.
1337 * m_getcl() - an mbuf + 2k cluster, sys/mbuf.h.
1338 * m_clget() - attach cluster to already allocated mbuf.
1339 * m_cljget() - attach jumbo cluster to already allocated mbuf.
1340 * m_get2() - allocate minimum mbuf that would fit size argument.
1341 * m_getm2() - allocate a chain of mbufs/clusters.
1342 * m_extadd() - attach external cluster to mbuf.
1344 * m_free() - free single mbuf with its tags and ext, sys/mbuf.h.
1345 * m_freem() - free chain of mbufs.
1349 m_clget(struct mbuf *m, int how)
1352 KASSERT((m->m_flags & M_EXT) == 0, ("%s: mbuf %p has M_EXT",
1354 m->m_ext.ext_buf = (char *)NULL;
1355 uma_zalloc_arg(zone_clust, m, how);
1357 * On a cluster allocation failure, drain the packet zone and retry,
1358 * we might be able to loosen a few clusters up on the drain.
1360 if ((how & M_NOWAIT) && (m->m_ext.ext_buf == NULL)) {
1361 uma_zone_reclaim(zone_pack, UMA_RECLAIM_DRAIN);
1362 uma_zalloc_arg(zone_clust, m, how);
1364 MBUF_PROBE2(m__clget, m, how);
1365 return (m->m_flags & M_EXT);
1369 * m_cljget() is different from m_clget() as it can allocate clusters without
1370 * attaching them to an mbuf. In that case the return value is the pointer
1371 * to the cluster of the requested size. If an mbuf was specified, it gets
1372 * the cluster attached to it and the return value can be safely ignored.
1373 * For size it takes MCLBYTES, MJUMPAGESIZE, MJUM9BYTES, MJUM16BYTES.
1376 m_cljget(struct mbuf *m, int how, int size)
1382 KASSERT((m->m_flags & M_EXT) == 0, ("%s: mbuf %p has M_EXT",
1384 m->m_ext.ext_buf = NULL;
1387 zone = m_getzone(size);
1388 retval = uma_zalloc_arg(zone, m, how);
1390 MBUF_PROBE4(m__cljget, m, how, size, retval);
1396 * m_get2() allocates minimum mbuf that would fit "size" argument.
1399 m_get2(int size, int how, short type, int flags)
1401 struct mb_args args;
1407 if (size <= MHLEN || (size <= MLEN && (flags & M_PKTHDR) == 0))
1408 return (uma_zalloc_arg(zone_mbuf, &args, how));
1409 if (size <= MCLBYTES)
1410 return (uma_zalloc_arg(zone_pack, &args, how));
1412 if (size > MJUMPAGESIZE)
1415 m = uma_zalloc_arg(zone_mbuf, &args, how);
1419 n = uma_zalloc_arg(zone_jumbop, m, how);
1421 uma_zfree(zone_mbuf, m);
1429 * m_getjcl() returns an mbuf with a cluster of the specified size attached.
1430 * For size it takes MCLBYTES, MJUMPAGESIZE, MJUM9BYTES, MJUM16BYTES.
1433 m_getjcl(int how, short type, int flags, int size)
1435 struct mb_args args;
1439 if (size == MCLBYTES)
1440 return m_getcl(how, type, flags);
1445 m = uma_zalloc_arg(zone_mbuf, &args, how);
1449 zone = m_getzone(size);
1450 n = uma_zalloc_arg(zone, m, how);
1452 uma_zfree(zone_mbuf, m);
1459 * Allocate a given length worth of mbufs and/or clusters (whatever fits
1460 * best) and return a pointer to the top of the allocated chain. If an
1461 * existing mbuf chain is provided, then we will append the new chain
1462 * to the existing one and return a pointer to the provided mbuf.
1465 m_getm2(struct mbuf *m, int len, int how, short type, int flags)
1467 struct mbuf *mb, *nm = NULL, *mtail = NULL;
1469 KASSERT(len >= 0, ("%s: len is < 0", __func__));
1471 /* Validate flags. */
1472 flags &= (M_PKTHDR | M_EOR);
1474 /* Packet header mbuf must be first in chain. */
1475 if ((flags & M_PKTHDR) && m != NULL)
1478 /* Loop and append maximum sized mbufs to the chain tail. */
1481 mb = m_getjcl(how, type, (flags & M_PKTHDR),
1483 else if (len >= MINCLSIZE)
1484 mb = m_getcl(how, type, (flags & M_PKTHDR));
1485 else if (flags & M_PKTHDR)
1486 mb = m_gethdr(how, type);
1488 mb = m_get(how, type);
1490 /* Fail the whole operation if one mbuf can't be allocated. */
1504 flags &= ~M_PKTHDR; /* Only valid on the first mbuf. */
1507 mtail->m_flags |= M_EOR; /* Only valid on the last mbuf. */
1509 /* If mbuf was supplied, append new chain to the end of it. */
1511 for (mtail = m; mtail->m_next != NULL; mtail = mtail->m_next)
1514 mtail->m_flags &= ~M_EOR;
1522 * Configure a provided mbuf to refer to the provided external storage
1523 * buffer and setup a reference count for said buffer.
1526 * mb The existing mbuf to which to attach the provided buffer.
1527 * buf The address of the provided external storage buffer.
1528 * size The size of the provided buffer.
1529 * freef A pointer to a routine that is responsible for freeing the
1530 * provided external storage buffer.
1531 * args A pointer to an argument structure (of any type) to be passed
1532 * to the provided freef routine (may be NULL).
1533 * flags Any other flags to be passed to the provided mbuf.
1534 * type The type that the external storage buffer should be
1541 m_extadd(struct mbuf *mb, char *buf, u_int size, m_ext_free_t freef,
1542 void *arg1, void *arg2, int flags, int type)
1545 KASSERT(type != EXT_CLUSTER, ("%s: EXT_CLUSTER not allowed", __func__));
1547 mb->m_flags |= (M_EXT | flags);
1548 mb->m_ext.ext_buf = buf;
1549 mb->m_data = mb->m_ext.ext_buf;
1550 mb->m_ext.ext_size = size;
1551 mb->m_ext.ext_free = freef;
1552 mb->m_ext.ext_arg1 = arg1;
1553 mb->m_ext.ext_arg2 = arg2;
1554 mb->m_ext.ext_type = type;
1556 if (type != EXT_EXTREF) {
1557 mb->m_ext.ext_count = 1;
1558 mb->m_ext.ext_flags = EXT_FLAG_EMBREF;
1560 mb->m_ext.ext_flags = 0;
1564 * Free an entire chain of mbufs and associated external buffers, if
1568 m_freem(struct mbuf *mb)
1571 MBUF_PROBE1(m__freem, mb);
1577 m_snd_tag_init(struct m_snd_tag *mst, struct ifnet *ifp)
1582 refcount_init(&mst->refcount, 1);
1583 counter_u64_add(snd_tag_count, 1);
1587 m_snd_tag_destroy(struct m_snd_tag *mst)
1592 ifp->if_snd_tag_free(mst);
1594 counter_u64_add(snd_tag_count, -1);