FreeBSD-5.3/sys/kern/kern_mbuf.c
/*-
* Copyright (c) 2004
* Bosko Milekic <bmilekic@FreeBSD.org>.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice unmodified, this list of conditions and the following
* disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the author nor the names of contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD: src/sys/kern/kern_mbuf.c,v 1.3 2004/08/02 00:18:35 green Exp $");
#include "opt_mac.h"
#include "opt_param.h"
#include <sys/param.h>
#include <sys/mac.h>
#include <sys/malloc.h>
#include <sys/systm.h>
#include <sys/mbuf.h>
#include <sys/domain.h>
#include <sys/eventhandler.h>
#include <sys/kernel.h>
#include <sys/protosw.h>
#include <sys/smp.h>
#include <sys/sysctl.h>
#include <vm/vm.h>
#include <vm/vm_page.h>
#include <vm/uma.h>
/*
* In FreeBSD, Mbufs and Mbuf Clusters are allocated from UMA
* Zones.
*
* Mbuf Clusters (2K, contiguous) are allocated from the Cluster
* Zone. The Zone can be capped at kern.ipc.nmbclusters, if the
* administrator so desires.
*
* Mbufs are allocated from a UMA Master Zone called the Mbuf
* Zone.
*
* Additionally, FreeBSD provides a Packet Zone, which it
* configures as a Secondary Zone to the Mbuf Master Zone,
* thus sharing backend Slab kegs with the Mbuf Master Zone.
*
* Thus common-case allocations and locking are simplified:
*
* m_clget() m_getcl()
* | |
* | .------------>[(Packet Cache)] m_get(), m_gethdr()
* | | [ Packet ] |
* [(Cluster Cache)] [ Secondary ] [ (Mbuf Cache) ]
* [ Cluster Zone ] [ Zone ] [ Mbuf Master Zone ]
* | \________ |
* [ Cluster Keg ] \ /
* | [ Mbuf Keg ]
* [ Cluster Slabs ] |
* | [ Mbuf Slabs ]
* \____________(VM)_________________/
*/
int nmbclusters;
struct mbstat mbstat;
static void
tunable_mbinit(void *dummy)
{
/* This has to be done before VM init. */
nmbclusters = 1024 + maxusers * 64;
TUNABLE_INT_FETCH("kern.ipc.nmbclusters", &nmbclusters);
}
SYSINIT(tunable_mbinit, SI_SUB_TUNABLES, SI_ORDER_ANY, tunable_mbinit, NULL);
SYSCTL_DECL(_kern_ipc);
SYSCTL_INT(_kern_ipc, OID_AUTO, nmbclusters, CTLFLAG_RW, &nmbclusters, 0,
"Maximum number of mbuf clusters allowed");
SYSCTL_STRUCT(_kern_ipc, OID_AUTO, mbstat, CTLFLAG_RD, &mbstat, mbstat,
"Mbuf general information and statistics");
/*
* Zones from which we allocate.
*/
uma_zone_t zone_mbuf;
uma_zone_t zone_clust;
uma_zone_t zone_pack;
/*
* Local prototypes.
*/
static int mb_ctor_mbuf(void *, int, void *, int);
static int mb_ctor_clust(void *, int, void *, int);
static int mb_ctor_pack(void *, int, void *, int);
static void mb_dtor_mbuf(void *, int, void *);
static void mb_dtor_clust(void *, int, void *); /* XXX */
static void mb_dtor_pack(void *, int, void *); /* XXX */
static int mb_init_pack(void *, int, int);
static void mb_fini_pack(void *, int);
static void mb_reclaim(void *);
static void mbuf_init(void *);
/*
* Initialize FreeBSD Network buffer allocation.
*/
SYSINIT(mbuf, SI_SUB_MBUF, SI_ORDER_FIRST, mbuf_init, NULL)
static void
mbuf_init(void *dummy)
{
/*
* Configure UMA zones for Mbufs, Clusters, and Packets.
*/
zone_mbuf = uma_zcreate("Mbuf", MSIZE, mb_ctor_mbuf, mb_dtor_mbuf,
NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_MAXBUCKET);
zone_clust = uma_zcreate("MbufClust", MCLBYTES, mb_ctor_clust,
mb_dtor_clust, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_REFCNT);
if (nmbclusters > 0)
uma_zone_set_max(zone_clust, nmbclusters);
zone_pack = uma_zsecond_create("Packet", mb_ctor_pack, mb_dtor_pack,
mb_init_pack, mb_fini_pack, zone_mbuf);
/* uma_prealloc() goes here */
/*
* Hook event handler for low-memory situation, used to
* drain protocols and push data back to the caches (UMA
* later pushes it back to VM).
*/
EVENTHANDLER_REGISTER(vm_lowmem, mb_reclaim, NULL,
EVENTHANDLER_PRI_FIRST);
/*
* [Re]set counters and local statistics knobs.
* XXX Some of these should go and be replaced, but UMA stat
* gathering needs to be revised.
*/
mbstat.m_mbufs = 0;
mbstat.m_mclusts = 0;
mbstat.m_drain = 0;
mbstat.m_msize = MSIZE;
mbstat.m_mclbytes = MCLBYTES;
mbstat.m_minclsize = MINCLSIZE;
mbstat.m_mlen = MLEN;
mbstat.m_mhlen = MHLEN;
mbstat.m_numtypes = MT_NTYPES;
mbstat.m_mcfail = mbstat.m_mpfail = 0;
mbstat.sf_iocnt = 0;
mbstat.sf_allocwait = mbstat.sf_allocfail = 0;
}
/*
* Constructor for Mbuf master zone.
*
* The 'arg' pointer points to a mb_args structure which
* contains call-specific information required to support the
* mbuf allocation API.
*/
static int
mb_ctor_mbuf(void *mem, int size, void *arg, int how)
{
struct mbuf *m;
struct mb_args *args;
#ifdef MAC
int error;
#endif
int flags;
short type;
m = (struct mbuf *)mem;
args = (struct mb_args *)arg;
flags = args->flags;
type = args->type;
m->m_type = type;
m->m_next = NULL;
m->m_nextpkt = NULL;
m->m_flags = flags;
if (flags & M_PKTHDR) {
m->m_data = m->m_pktdat;
m->m_pkthdr.rcvif = NULL;
m->m_pkthdr.csum_flags = 0;
SLIST_INIT(&m->m_pkthdr.tags);
#ifdef MAC
/* If the label init fails, fail the alloc */
error = mac_init_mbuf(m, how);
if (error)
return (error);
#endif
} else
m->m_data = m->m_dat;
mbstat.m_mbufs += 1; /* XXX */
return (0);
}
/*
* The Mbuf master zone and Packet secondary zone destructor.
*/
static void
mb_dtor_mbuf(void *mem, int size, void *arg)
{
struct mbuf *m;
m = (struct mbuf *)mem;
if ((m->m_flags & M_PKTHDR) != 0)
m_tag_delete_chain(m, NULL);
mbstat.m_mbufs -= 1; /* XXX */
}
/* XXX Only because of stats */
static void
mb_dtor_pack(void *mem, int size, void *arg)
{
struct mbuf *m;
m = (struct mbuf *)mem;
if ((m->m_flags & M_PKTHDR) != 0)
m_tag_delete_chain(m, NULL);
mbstat.m_mbufs -= 1; /* XXX */
mbstat.m_mclusts -= 1; /* XXX */
}
/*
* The Cluster zone constructor.
*
* Here the 'arg' pointer points to the Mbuf which we
* are configuring cluster storage for.
*/
static int
mb_ctor_clust(void *mem, int size, void *arg, int how)
{
struct mbuf *m;
m = (struct mbuf *)arg;
m->m_ext.ext_buf = (caddr_t)mem;
m->m_data = m->m_ext.ext_buf;
m->m_flags |= M_EXT;
m->m_ext.ext_free = NULL;
m->m_ext.ext_args = NULL;
m->m_ext.ext_size = MCLBYTES;
m->m_ext.ext_type = EXT_CLUSTER;
m->m_ext.ref_cnt = (u_int *)uma_find_refcnt(zone_clust,
m->m_ext.ext_buf);
*(m->m_ext.ref_cnt) = 1;
mbstat.m_mclusts += 1; /* XXX */
return (0);
}
/* XXX */
static void
mb_dtor_clust(void *mem, int size, void *arg)
{
mbstat.m_mclusts -= 1; /* XXX */
}
/*
* The Packet secondary zone's init routine, executed on the
* object's transition from keg slab to zone cache.
*/
static int
mb_init_pack(void *mem, int size, int how)
{
struct mbuf *m;
m = (struct mbuf *)mem;
m->m_ext.ext_buf = NULL;
uma_zalloc_arg(zone_clust, m, how);
if (m->m_ext.ext_buf == NULL)
return (ENOMEM);
mbstat.m_mclusts -= 1; /* XXX */
return (0);
}
/*
* The Packet secondary zone's fini routine, executed on the
* object's transition from zone cache to keg slab.
*/
static void
mb_fini_pack(void *mem, int size)
{
struct mbuf *m;
m = (struct mbuf *)mem;
uma_zfree_arg(zone_clust, m->m_ext.ext_buf, NULL);
m->m_ext.ext_buf = NULL;
mbstat.m_mclusts += 1; /* XXX */
}
/*
* The "packet" keg constructor.
*/
static int
mb_ctor_pack(void *mem, int size, void *arg, int how)
{
struct mbuf *m;
struct mb_args *args;
#ifdef MAC
int error;
#endif
int flags;
short type;
m = (struct mbuf *)mem;
args = (struct mb_args *)arg;
flags = args->flags;
type = args->type;
m->m_type = type;
m->m_next = NULL;
m->m_nextpkt = NULL;
m->m_data = m->m_ext.ext_buf;
m->m_flags = flags|M_EXT;
m->m_ext.ext_free = NULL;
m->m_ext.ext_args = NULL;
m->m_ext.ext_size = MCLBYTES;
m->m_ext.ext_type = EXT_PACKET;
*(m->m_ext.ref_cnt) = 1;
if (flags & M_PKTHDR) {
m->m_pkthdr.rcvif = NULL;
m->m_pkthdr.csum_flags = 0;
SLIST_INIT(&m->m_pkthdr.tags);
#ifdef MAC
/* If the label init fails, fail the alloc */
error = mac_init_mbuf(m, how);
if (error)
return (error);
#endif
}
mbstat.m_mbufs += 1; /* XXX */
mbstat.m_mclusts += 1; /* XXX */
return (0);
}
/*
* This is the protocol drain routine.
*
* No locks should be held when this is called. The drain routines have to
* presently acquire some locks which raises the possibility of lock order
* reversal.
*/
static void
mb_reclaim(void *junk)
{
struct domain *dp;
struct protosw *pr;
WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK | WARN_PANIC, NULL,
"mb_reclaim()");
mbstat.m_drain++;
for (dp = domains; dp != NULL; dp = dp->dom_next)
for (pr = dp->dom_protosw; pr < dp->dom_protoswNPROTOSW; pr++)
if (pr->pr_drain != NULL)
(*pr->pr_drain)();
}