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- change the buffer size from a constant to a

Browse Source 
TUNABLE variable (hw.netmap.buf_size) so we can experiment
  with values different from 2048 which may give better cache performance.

- rearrange the memory allocation code so it will be easier
  to replace it with a different implementation. The current code
  relies on a single large contiguous chunk of memory obtained through
  contigmalloc.
  The new implementation (not committed yet) uses multiple
  smaller chunks which are easier to fit in a fragmented address
  space.
This commit is contained in:
Luigi Rizzo 2012-02-08 11:43:29 +00:00
parent 78674822c7
commit 5819da83ce
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=231198
10 changed files with 444 additions and 450 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
sys/dev/netmap/if_em_netmap.h
View File

@ -61,7 +61,6 @@ em_netmap_attach(struct adapter *adapter)
na.nm_rxsync = em_netmap_rxsync;
na.nm_lock = em_netmap_lock_wrapper;
na.nm_register = em_netmap_reg;
na.buff_size = NETMAP_BUF_SIZE;
netmap_attach(&na, adapter->num_queues);
}

1
sys/dev/netmap/if_igb_netmap.h
View File

@ -58,7 +58,6 @@ igb_netmap_attach(struct adapter *adapter)
na.nm_rxsync = igb_netmap_rxsync;
na.nm_lock = igb_netmap_lock_wrapper;
na.nm_register = igb_netmap_reg;
na.buff_size = NETMAP_BUF_SIZE;
netmap_attach(&na, adapter->num_queues);
}

6
sys/dev/netmap/if_lem_netmap.h
View File

@ -62,7 +62,6 @@ lem_netmap_attach(struct adapter *adapter)
na.nm_rxsync = lem_netmap_rxsync;
na.nm_lock = lem_netmap_lock_wrapper;
na.nm_register = lem_netmap_reg;
na.buff_size = NETMAP_BUF_SIZE;
netmap_attach(&na, 1);
}
@ -247,6 +246,7 @@ lem_netmap_txsync(void *a, u_int ring_nr, int do_lock)
ring->avail = kring->nr_hwavail;
}
}
if (do_lock)
EM_TX_UNLOCK(adapter);
return 0;
@ -351,9 +351,9 @@ lem_netmap_rxsync(void *a, u_int ring_nr, int do_lock)
/* tell userspace that there are new packets */
ring->avail = kring->nr_hwavail ;
if (do_lock)
EM_RX_UNLOCK(adapter);
return 0;
}
/* end of file */

1
sys/dev/netmap/if_re_netmap.h
View File

@ -56,7 +56,6 @@ re_netmap_attach(struct rl_softc *sc)
na.nm_rxsync = re_netmap_rxsync;
na.nm_lock = re_netmap_lock_wrapper;
na.nm_register = re_netmap_reg;
na.buff_size = NETMAP_BUF_SIZE;
netmap_attach(&na, 1);
}

17
sys/dev/netmap/ixgbe_netmap.h
View File

@ -82,13 +82,6 @@ ixgbe_netmap_attach(struct adapter *adapter)
na.nm_rxsync = ixgbe_netmap_rxsync;
na.nm_lock = ixgbe_netmap_lock_wrapper;
na.nm_register = ixgbe_netmap_reg;
/*
* XXX where do we put this comment ?
* adapter->rx_mbuf_sz is set by SIOCSETMTU, but in netmap mode
* we allocate the buffers on the first register. So we must
* disallow a SIOCSETMTU when if_capenable & IFCAP_NETMAP is set.
*/
na.buff_size = NETMAP_BUF_SIZE;
netmap_attach(&na, adapter->num_queues);
}
@ -354,7 +347,8 @@ ixgbe_netmap_txsync(void *a, u_int ring_nr, int do_lock)
* otherwise we go to sleep (in netmap_poll()) and will be
* woken up when slot nr_kflags will be ready.
*/
struct ixgbe_legacy_tx_desc *txd = (struct ixgbe_legacy_tx_desc *)txr->tx_base;
struct ixgbe_legacy_tx_desc *txd =
(struct ixgbe_legacy_tx_desc *)txr->tx_base;
j = txr->next_to_clean + kring->nkr_num_slots/2;
if (j >= kring->nkr_num_slots)
@ -365,9 +359,7 @@ ixgbe_netmap_txsync(void *a, u_int ring_nr, int do_lock)
kring->nr_kflags = j; /* the slot to check */
j = txd[j].upper.fields.status & IXGBE_TXD_STAT_DD;
}
if (!j) {
netmap_skip_txsync++;
} else {
if (j) {
int delta;
/*
@ -471,7 +463,7 @@ ixgbe_netmap_rxsync(void *a, u_int ring_nr, int do_lock)
if (j > lim)
j -= lim + 1;
if (force_update) {
if (netmap_no_pendintr || force_update) {
for (n = 0; ; n++) {
union ixgbe_adv_rx_desc *curr = &rxr->rx_base[l];
uint32_t staterr = le32toh(curr->wb.upper.status_error);
@ -548,6 +540,7 @@ ixgbe_netmap_rxsync(void *a, u_int ring_nr, int do_lock)
}
/* tell userspace that there are new packets */
ring->avail = kring->nr_hwavail ;
if (do_lock)
IXGBE_RX_UNLOCK(rxr);
return 0;

840
sys/dev/netmap/netmap.c
View File

@ -92,6 +92,39 @@ MALLOC_DEFINE(M_NETMAP, "netmap", "Network memory map");
*/
#define NMA_LOCK() mtx_lock(&netmap_mem_d->nm_mtx);
#define NMA_UNLOCK() mtx_unlock(&netmap_mem_d->nm_mtx);
struct netmap_mem_d;
static struct netmap_mem_d *netmap_mem_d; /* Our memory allocator. */
u_int netmap_total_buffers;
char *netmap_buffer_base; /* address of an invalid buffer */
/* user-controlled variables */
int netmap_verbose;
static int netmap_no_timestamp; /* don't timestamp on rxsync */
SYSCTL_NODE(_dev, OID_AUTO, netmap, CTLFLAG_RW, 0, "Netmap args");
SYSCTL_INT(_dev_netmap, OID_AUTO, verbose,
CTLFLAG_RW, &netmap_verbose, 0, "Verbose mode");
SYSCTL_INT(_dev_netmap, OID_AUTO, no_timestamp,
CTLFLAG_RW, &netmap_no_timestamp, 0, "no_timestamp");
int netmap_buf_size = 2048;
TUNABLE_INT("hw.netmap.buf_size", &netmap_buf_size);
SYSCTL_INT(_dev_netmap, OID_AUTO, buf_size,
CTLFLAG_RD, &netmap_buf_size, 0, "Size of packet buffers");
int netmap_mitigate = 1;
SYSCTL_INT(_dev_netmap, OID_AUTO, mitigate, CTLFLAG_RW, &netmap_mitigate, 0, "");
int netmap_no_pendintr;
SYSCTL_INT(_dev_netmap, OID_AUTO, no_pendintr,
CTLFLAG_RW, &netmap_no_pendintr, 0, "Always look for new received packets.");
/*----- memory allocator -----------------*/
/*
* Here we have the low level routines for memory allocator
* and its primary users.
*/
/*
* Default amount of memory pre-allocated by the module.
@ -128,30 +161,13 @@ struct netmap_buf_pool {
uint32_t *bitmap; /* one bit per buffer, 1 means free */
};
struct netmap_buf_pool nm_buf_pool;
/* XXX move these two vars back into netmap_buf_pool */
u_int netmap_total_buffers;
char *netmap_buffer_base; /* address of an invalid buffer */
/* user-controlled variables */
int netmap_verbose;
static int no_timestamp; /* don't timestamp on rxsync */
SYSCTL_NODE(_dev, OID_AUTO, netmap, CTLFLAG_RW, 0, "Netmap args");
SYSCTL_INT(_dev_netmap, OID_AUTO, verbose,
CTLFLAG_RW, &netmap_verbose, 0, "Verbose mode");
SYSCTL_INT(_dev_netmap, OID_AUTO, no_timestamp,
CTLFLAG_RW, &no_timestamp, 0, "no_timestamp");
SYSCTL_INT(_dev_netmap, OID_AUTO, total_buffers,
CTLFLAG_RD, &nm_buf_pool.total_buffers, 0, "total_buffers");
SYSCTL_INT(_dev_netmap, OID_AUTO, free_buffers,
CTLFLAG_RD, &nm_buf_pool.free, 0, "free_buffers");
int netmap_mitigate = 1;
SYSCTL_INT(_dev_netmap, OID_AUTO, mitigate, CTLFLAG_RW, &netmap_mitigate, 0, "");
int netmap_skip_txsync;
SYSCTL_INT(_dev_netmap, OID_AUTO, skip_txsync, CTLFLAG_RW, &netmap_skip_txsync, 0, "");
int netmap_skip_rxsync;
SYSCTL_INT(_dev_netmap, OID_AUTO, skip_rxsync, CTLFLAG_RW, &netmap_skip_rxsync, 0, "");
/*
* Allocate n buffers from the ring, and fill the slot.
@ -239,6 +255,373 @@ struct netmap_mem_d {
area. */
};
/* Shorthand to compute a netmap interface offset. */
#define netmap_if_offset(v) \
((char *) (v) - (char *) netmap_mem_d->nm_buffer)
/* .. and get a physical address given a memory offset */
#define netmap_ofstophys(o) \
(vtophys(netmap_mem_d->nm_buffer) + (o))
/*------ netmap memory allocator -------*/
/*
* Request for a chunk of memory.
*
* Memory objects are arranged into a list, hence we need to walk this
* list until we find an object with the needed amount of data free.
* This sounds like a completely inefficient implementation, but given
* the fact that data allocation is done once, we can handle it
* flawlessly.
*
* Return NULL on failure.
*/
static void *
netmap_malloc(size_t size, __unused const char *msg)
{
struct netmap_mem_obj *mem_obj, *new_mem_obj;
void *ret = NULL;
NMA_LOCK();
TAILQ_FOREACH(mem_obj, &netmap_mem_d->nm_molist, nmo_next) {
if (mem_obj->nmo_used != 0 || mem_obj->nmo_size < size)
continue;
new_mem_obj = malloc(sizeof(struct netmap_mem_obj), M_NETMAP,
M_WAITOK | M_ZERO);
TAILQ_INSERT_BEFORE(mem_obj, new_mem_obj, nmo_next);
new_mem_obj->nmo_used = 1;
new_mem_obj->nmo_size = size;
new_mem_obj->nmo_data = mem_obj->nmo_data;
memset(new_mem_obj->nmo_data, 0, new_mem_obj->nmo_size);
mem_obj->nmo_size -= size;
mem_obj->nmo_data = (char *) mem_obj->nmo_data + size;
if (mem_obj->nmo_size == 0) {
TAILQ_REMOVE(&netmap_mem_d->nm_molist, mem_obj,
nmo_next);
free(mem_obj, M_NETMAP);
}
ret = new_mem_obj->nmo_data;
break;
}
NMA_UNLOCK();
ND("%s: %d bytes at %p", msg, size, ret);
return (ret);
}
/*
* Return the memory to the allocator.
*
* While freeing a memory object, we try to merge adjacent chunks in
* order to reduce memory fragmentation.
*/
static void
netmap_free(void *addr, const char *msg)
{
size_t size;
struct netmap_mem_obj *cur, *prev, *next;
if (addr == NULL) {
D("NULL addr for %s", msg);
return;
}
NMA_LOCK();
TAILQ_FOREACH(cur, &netmap_mem_d->nm_molist, nmo_next) {
if (cur->nmo_data == addr && cur->nmo_used)
break;
}
if (cur == NULL) {
NMA_UNLOCK();
D("invalid addr %s %p", msg, addr);
return;
}
size = cur->nmo_size;
cur->nmo_used = 0;
/* merge current chunk of memory with the previous one,
if present. */
prev = TAILQ_PREV(cur, netmap_mem_obj_h, nmo_next);
if (prev && prev->nmo_used == 0) {
TAILQ_REMOVE(&netmap_mem_d->nm_molist, cur, nmo_next);
prev->nmo_size += cur->nmo_size;
free(cur, M_NETMAP);
cur = prev;
}
/* merge with the next one */
next = TAILQ_NEXT(cur, nmo_next);
if (next && next->nmo_used == 0) {
TAILQ_REMOVE(&netmap_mem_d->nm_molist, next, nmo_next);
cur->nmo_size += next->nmo_size;
free(next, M_NETMAP);
}
NMA_UNLOCK();
ND("freed %s %d bytes at %p", msg, size, addr);
}
/*
* Create and return a new ``netmap_if`` object, and possibly also
* rings and packet buffors.
*
* Return NULL on failure.
*/
static void *
netmap_if_new(const char *ifname, struct netmap_adapter *na)
{
struct netmap_if *nifp;
struct netmap_ring *ring;
char *buff;
u_int i, len, ofs;
u_int n = na->num_queues + 1; /* shorthand, include stack queue */
/*
* the descriptor is followed inline by an array of offsets
* to the tx and rx rings in the shared memory region.
*/
len = sizeof(struct netmap_if) + 2 * n * sizeof(ssize_t);
nifp = netmap_if_malloc(len);
if (nifp == NULL)
return (NULL);
/* initialize base fields */
*(int *)(uintptr_t)&nifp->ni_num_queues = na->num_queues;
strncpy(nifp->ni_name, ifname, IFNAMSIZ);
(na->refcount)++; /* XXX atomic ? we are under lock */
if (na->refcount > 1)
goto final;
/*
* If this is the first instance, allocate the shadow rings and
* buffers for this card (one for each hw queue, one for the host).
* The rings are contiguous, but have variable size.
* The entire block is reachable at
* na->tx_rings[0].ring
*/
len = n * (2 * sizeof(struct netmap_ring) +
(na->num_tx_desc + na->num_rx_desc) *
sizeof(struct netmap_slot) );
buff = netmap_ring_malloc(len);
if (buff == NULL) {
D("failed to allocate %d bytes for %s shadow ring",
len, ifname);
error:
(na->refcount)--;
netmap_if_free(nifp);
return (NULL);
}
/* do we have the bufers ? we are in need of num_tx_desc buffers for
* each tx ring and num_tx_desc buffers for each rx ring. */
len = n * (na->num_tx_desc + na->num_rx_desc);
NMA_LOCK();
if (nm_buf_pool.free < len) {
NMA_UNLOCK();
netmap_free(buff, "not enough bufs");
goto error;
}
/*
* in the kring, store the pointers to the shared rings
* and initialize the rings. We are under NMA_LOCK().
*/
ofs = 0;
for (i = 0; i < n; i++) {
struct netmap_kring *kring;
int numdesc;
/* Transmit rings */
kring = &na->tx_rings[i];
numdesc = na->num_tx_desc;
bzero(kring, sizeof(*kring));
kring->na = na;
ring = kring->ring = (struct netmap_ring *)(buff + ofs);
*(ssize_t *)(uintptr_t)&ring->buf_ofs =
nm_buf_pool.base - (char *)ring;
ND("txring[%d] at %p ofs %d", i, ring, ring->buf_ofs);
*(uint32_t *)(uintptr_t)&ring->num_slots =
kring->nkr_num_slots = numdesc;
/*
* IMPORTANT:
* Always keep one slot empty, so we can detect new
* transmissions comparing cur and nr_hwcur (they are
* the same only if there are no new transmissions).
*/
ring->avail = kring->nr_hwavail = numdesc - 1;
ring->cur = kring->nr_hwcur = 0;
*(uint16_t *)(uintptr_t)&ring->nr_buf_size = NETMAP_BUF_SIZE;
netmap_new_bufs(nifp, ring->slot, numdesc);
ofs += sizeof(struct netmap_ring) +
numdesc * sizeof(struct netmap_slot);
/* Receive rings */
kring = &na->rx_rings[i];
numdesc = na->num_rx_desc;
bzero(kring, sizeof(*kring));
kring->na = na;
ring = kring->ring = (struct netmap_ring *)(buff + ofs);
*(ssize_t *)(uintptr_t)&ring->buf_ofs =
nm_buf_pool.base - (char *)ring;
ND("rxring[%d] at %p offset %d", i, ring, ring->buf_ofs);
*(uint32_t *)(uintptr_t)&ring->num_slots =
kring->nkr_num_slots = numdesc;
ring->cur = kring->nr_hwcur = 0;
ring->avail = kring->nr_hwavail = 0; /* empty */
*(uint16_t *)(uintptr_t)&ring->nr_buf_size = NETMAP_BUF_SIZE;
netmap_new_bufs(nifp, ring->slot, numdesc);
ofs += sizeof(struct netmap_ring) +
numdesc * sizeof(struct netmap_slot);
}
NMA_UNLOCK();
for (i = 0; i < n+1; i++) {
// XXX initialize the selrecord structs.
}
final:
/*
* fill the slots for the rx and tx queues. They contain the offset
* between the ring and nifp, so the information is usable in
* userspace to reach the ring from the nifp.
*/
for (i = 0; i < n; i++) {
char *base = (char *)nifp;
*(ssize_t *)(uintptr_t)&nifp->ring_ofs[i] =
(char *)na->tx_rings[i].ring - base;
*(ssize_t *)(uintptr_t)&nifp->ring_ofs[i+n] =
(char *)na->rx_rings[i].ring - base;
}
return (nifp);
}
/*
* Initialize the memory allocator.
*
* Create the descriptor for the memory , allocate the pool of memory
* and initialize the list of memory objects with a single chunk
* containing the whole pre-allocated memory marked as free.
*
* Start with a large size, then halve as needed if we fail to
* allocate the block. While halving, always add one extra page
* because buffers 0 and 1 are used for special purposes.
* Return 0 on success, errno otherwise.
*/
static int
netmap_memory_init(void)
{
struct netmap_mem_obj *mem_obj;
void *buf = NULL;
int i, n, sz = NETMAP_MEMORY_SIZE;
int extra_sz = 0; // space for rings and two spare buffers
for (; sz >= 1<<20; sz >>=1) {
extra_sz = sz/200;
extra_sz = (extra_sz + 2*PAGE_SIZE - 1) & ~(PAGE_SIZE-1);
buf = contigmalloc(sz + extra_sz,
M_NETMAP,
M_WAITOK | M_ZERO,
0, /* low address */
-1UL, /* high address */
PAGE_SIZE, /* alignment */
0 /* boundary */
);
if (buf)
break;
}
if (buf == NULL)
return (ENOMEM);
sz += extra_sz;
netmap_mem_d = malloc(sizeof(struct netmap_mem_d), M_NETMAP,
M_WAITOK | M_ZERO);
mtx_init(&netmap_mem_d->nm_mtx, "netmap memory allocator lock", NULL,
MTX_DEF);
TAILQ_INIT(&netmap_mem_d->nm_molist);
netmap_mem_d->nm_buffer = buf;
netmap_mem_d->nm_totalsize = sz;
/*
* A buffer takes 2k, a slot takes 8 bytes + ring overhead,
* so the ratio is 200:1. In other words, we can use 1/200 of
* the memory for the rings, and the rest for the buffers,
* and be sure we never run out.
*/
netmap_mem_d->nm_size = sz/200;
netmap_mem_d->nm_buf_start =
(netmap_mem_d->nm_size + PAGE_SIZE - 1) & ~(PAGE_SIZE-1);
netmap_mem_d->nm_buf_len = sz - netmap_mem_d->nm_buf_start;
nm_buf_pool.base = netmap_mem_d->nm_buffer;
nm_buf_pool.base += netmap_mem_d->nm_buf_start;
netmap_buffer_base = nm_buf_pool.base;
D("netmap_buffer_base %p (offset %d)",
netmap_buffer_base, (int)netmap_mem_d->nm_buf_start);
/* number of buffers, they all start as free */
netmap_total_buffers = nm_buf_pool.total_buffers =
netmap_mem_d->nm_buf_len / NETMAP_BUF_SIZE;
nm_buf_pool.bufsize = NETMAP_BUF_SIZE;
D("Have %d MB, use %dKB for rings, %d buffers at %p",
(sz >> 20), (int)(netmap_mem_d->nm_size >> 10),
nm_buf_pool.total_buffers, nm_buf_pool.base);
/* allocate and initialize the bitmap. Entry 0 is considered
* always busy (used as default when there are no buffers left).
*/
n = (nm_buf_pool.total_buffers + 31) / 32;
nm_buf_pool.bitmap = malloc(sizeof(uint32_t) * n, M_NETMAP,
M_WAITOK | M_ZERO);
nm_buf_pool.bitmap[0] = ~3; /* slot 0 and 1 always busy */
for (i = 1; i < n; i++)
nm_buf_pool.bitmap[i] = ~0;
nm_buf_pool.free = nm_buf_pool.total_buffers - 2;
mem_obj = malloc(sizeof(struct netmap_mem_obj), M_NETMAP,
M_WAITOK | M_ZERO);
TAILQ_INSERT_HEAD(&netmap_mem_d->nm_molist, mem_obj, nmo_next);
mem_obj->nmo_used = 0;
mem_obj->nmo_size = netmap_mem_d->nm_size;
mem_obj->nmo_data = netmap_mem_d->nm_buffer;
return (0);
}
/*
* Finalize the memory allocator.
*
* Free all the memory objects contained inside the list, and deallocate
* the pool of memory; finally free the memory allocator descriptor.
*/
static void
netmap_memory_fini(void)
{
struct netmap_mem_obj *mem_obj;
while (!TAILQ_EMPTY(&netmap_mem_d->nm_molist)) {
mem_obj = TAILQ_FIRST(&netmap_mem_d->nm_molist);
TAILQ_REMOVE(&netmap_mem_d->nm_molist, mem_obj, nmo_next);
if (mem_obj->nmo_used == 1) {
printf("netmap: leaked %d bytes at %p\n",
(int)mem_obj->nmo_size,
mem_obj->nmo_data);
}
free(mem_obj, M_NETMAP);
}
contigfree(netmap_mem_d->nm_buffer, netmap_mem_d->nm_totalsize, M_NETMAP);
// XXX mutex_destroy(nm_mtx);
free(netmap_mem_d, M_NETMAP);
}
/*------------- end of memory allocator -----------------*/
/* Structure associated to each thread which registered an interface. */
struct netmap_priv_d {
@ -250,15 +633,8 @@ struct netmap_priv_d {
uint16_t np_txpoll;
};
/* Shorthand to compute a netmap interface offset. */
#define netmap_if_offset(v) \
((char *) (v) - (char *) netmap_mem_d->nm_buffer)
/* .. and get a physical address given a memory offset */
#define netmap_ofstophys(o) \
(vtophys(netmap_mem_d->nm_buffer) + (o))
static struct cdev *netmap_dev; /* /dev/netmap character device. */
static struct netmap_mem_d *netmap_mem_d; /* Our memory allocator. */
static d_mmap_t netmap_mmap;
@ -351,6 +727,7 @@ netmap_kqfilter(struct cdev *dev, struct knote *kn)
}
#endif /* NETMAP_KEVENT */
/*
* File descriptor's private data destructor.
*
@ -358,19 +735,13 @@ netmap_kqfilter(struct cdev *dev, struct knote *kn)
* revert to normal operation. We expect that np_ifp has not gone.
*/
static void
netmap_dtor(void *data)
netmap_dtor_locked(void *data)
{
struct netmap_priv_d *priv = data;
struct ifnet *ifp = priv->np_ifp;
struct netmap_adapter *na = NA(ifp);
struct netmap_if *nifp = priv->np_nifp;
if (0)
printf("%s starting for %p ifp %p\n", __FUNCTION__, priv,
priv ? priv->np_ifp : NULL);
na->nm_lock(ifp->if_softc, NETMAP_CORE_LOCK, 0);
na->refcount--;
if (na->refcount <= 0) { /* last instance */
u_int i;
@ -422,148 +793,23 @@ netmap_dtor(void *data)
wakeup(na);
}
netmap_if_free(nifp);
na->nm_lock(ifp->if_softc, NETMAP_CORE_UNLOCK, 0);
if_rele(ifp);
bzero(priv, sizeof(*priv)); /* XXX for safety */
free(priv, M_DEVBUF);
}
/*
* Create and return a new ``netmap_if`` object, and possibly also
* rings and packet buffors.
*
* Return NULL on failure.
*/
static void *
netmap_if_new(const char *ifname, struct netmap_adapter *na)
static void
netmap_dtor(void *data)
{
struct netmap_if *nifp;
struct netmap_ring *ring;
char *buff;
u_int i, len, ofs;
u_int n = na->num_queues + 1; /* shorthand, include stack queue */
struct netmap_priv_d *priv = data;
struct ifnet *ifp = priv->np_ifp;
struct netmap_adapter *na = NA(ifp);
/*
* the descriptor is followed inline by an array of offsets
* to the tx and rx rings in the shared memory region.
*/
len = sizeof(struct netmap_if) + 2 * n * sizeof(ssize_t);
nifp = netmap_if_malloc(len);
if (nifp == NULL)
return (NULL);
na->nm_lock(ifp->if_softc, NETMAP_CORE_LOCK, 0);
netmap_dtor_locked(data);
na->nm_lock(ifp->if_softc, NETMAP_CORE_UNLOCK, 0);
/* initialize base fields */
*(int *)(uintptr_t)&nifp->ni_num_queues = na->num_queues;
strncpy(nifp->ni_name, ifname, IFNAMSIZ);
(na->refcount)++; /* XXX atomic ? we are under lock */
if (na->refcount > 1)
goto final;
/*
* If this is the first instance, allocate the shadow rings and
* buffers for this card (one for each hw queue, one for the host).
* The rings are contiguous, but have variable size.
* The entire block is reachable at
* na->tx_rings[0].ring
*/
len = n * (2 * sizeof(struct netmap_ring) +
(na->num_tx_desc + na->num_rx_desc) *
sizeof(struct netmap_slot) );
buff = netmap_ring_malloc(len);
if (buff == NULL) {
D("failed to allocate %d bytes for %s shadow ring",
len, ifname);
error:
(na->refcount)--;
netmap_if_free(nifp);
return (NULL);
}
/* do we have the bufers ? we are in need of num_tx_desc buffers for
* each tx ring and num_tx_desc buffers for each rx ring. */
len = n * (na->num_tx_desc + na->num_rx_desc);
NMA_LOCK();
if (nm_buf_pool.free < len) {
NMA_UNLOCK();
netmap_free(buff, "not enough bufs");
goto error;
}
/*
* in the kring, store the pointers to the shared rings
* and initialize the rings. We are under NMA_LOCK().
*/
ofs = 0;
for (i = 0; i < n; i++) {
struct netmap_kring *kring;
int numdesc;
/* Transmit rings */
kring = &na->tx_rings[i];
numdesc = na->num_tx_desc;
bzero(kring, sizeof(*kring));
kring->na = na;
ring = kring->ring = (struct netmap_ring *)(buff + ofs);
*(ssize_t *)(uintptr_t)&ring->buf_ofs =
nm_buf_pool.base - (char *)ring;
ND("txring[%d] at %p ofs %d", i, ring, ring->buf_ofs);
*(int *)(int *)(uintptr_t)&ring->num_slots =
kring->nkr_num_slots = numdesc;
/*
* IMPORTANT:
* Always keep one slot empty, so we can detect new
* transmissions comparing cur and nr_hwcur (they are
* the same only if there are no new transmissions).
*/
ring->avail = kring->nr_hwavail = numdesc - 1;
ring->cur = kring->nr_hwcur = 0;
netmap_new_bufs(nifp, ring->slot, numdesc);
ofs += sizeof(struct netmap_ring) +
numdesc * sizeof(struct netmap_slot);
/* Receive rings */
kring = &na->rx_rings[i];
numdesc = na->num_rx_desc;
bzero(kring, sizeof(*kring));
kring->na = na;
ring = kring->ring = (struct netmap_ring *)(buff + ofs);
*(ssize_t *)(uintptr_t)&ring->buf_ofs =
nm_buf_pool.base - (char *)ring;
ND("rxring[%d] at %p offset %d", i, ring, ring->buf_ofs);
*(int *)(int *)(uintptr_t)&ring->num_slots =
kring->nkr_num_slots = numdesc;
ring->cur = kring->nr_hwcur = 0;
ring->avail = kring->nr_hwavail = 0; /* empty */
netmap_new_bufs(nifp, ring->slot, numdesc);
ofs += sizeof(struct netmap_ring) +
numdesc * sizeof(struct netmap_slot);
}
NMA_UNLOCK();
for (i = 0; i < n+1; i++) {
// XXX initialize the selrecord structs.
}
final:
/*
* fill the slots for the rx and tx queues. They contain the offset
* between the ring and nifp, so the information is usable in
* userspace to reach the ring from the nifp.
*/
for (i = 0; i < n; i++) {
char *base = (char *)nifp;
*(ssize_t *)(uintptr_t)&nifp->ring_ofs[i] =
(char *)na->tx_rings[i].ring - base;
*(ssize_t *)(uintptr_t)&nifp->ring_ofs[i+n] =
(char *)na->rx_rings[i].ring - base;
}
return (nifp);
if_rele(ifp);
bzero(priv, sizeof(*priv)); /* XXX for safety */
free(priv, M_DEVBUF);
}
@ -894,7 +1140,6 @@ netmap_ioctl(__unused struct cdev *dev, u_long cmd, caddr_t data,
break;
}
for (i = 10; i > 0; i--) {
na->nm_lock(adapter, NETMAP_CORE_LOCK, 0);
if (!NETMAP_DELETING(na))
@ -924,25 +1169,16 @@ netmap_ioctl(__unused struct cdev *dev, u_long cmd, caddr_t data,
* and make it use the shared buffers.
*/
error = na->nm_register(ifp, 1); /* mode on */
if (error) {
/*
* do something similar to netmap_dtor().
*/
netmap_free_rings(na);
// XXX tx_rings is inline, must not be freed.
// free(na->tx_rings, M_DEVBUF); // XXX wrong ?
na->tx_rings = na->rx_rings = NULL;
na->refcount--;
netmap_if_free(nifp);
nifp = NULL;
}
if (error)
netmap_dtor_locked(priv);
}
if (error) { /* reg. failed, release priv and ref */
error:
na->nm_lock(adapter, NETMAP_CORE_UNLOCK, 0);
free(priv, M_DEVBUF);
if_rele(ifp); /* return the refcount */
bzero(priv, sizeof(*priv));
free(priv, M_DEVBUF);
break;
}
@ -1166,6 +1402,12 @@ netmap_poll(__unused struct cdev *dev, int events, struct thread *td)
if (priv->np_txpoll || want_tx) {
for (i = priv->np_qfirst; i < priv->np_qlast; i++) {
kring = &na->tx_rings[i];
/*
* Skip the current ring if want_tx == 0
* (we have already done a successful sync on
* a previous ring) AND kring->cur == kring->hwcur
* (there are no pending transmissions for this ring).
*/
if (!want_tx && kring->ring->cur == kring->nr_hwcur)
continue;
if (core_lock == NEED_CL) {
@ -1181,6 +1423,7 @@ netmap_poll(__unused struct cdev *dev, int events, struct thread *td)
if (na->nm_txsync(adapter, i, 0 /* no lock */))
revents |= POLLERR;
/* Check avail/call selrecord only if called with POLLOUT */
if (want_tx) {
if (kring->ring->avail > 0) {
/* stop at the first ring. We don't risk
@ -1212,9 +1455,10 @@ netmap_poll(__unused struct cdev *dev, int events, struct thread *td)
if (na->nm_rxsync(adapter, i, 0 /* no lock */))
revents |= POLLERR;
if (no_timestamp == 0 ||
kring->ring->flags & NR_TIMESTAMP)
if (netmap_no_timestamp == 0 ||
kring->ring->flags & NR_TIMESTAMP) {
microtime(&kring->ring->ts);
}
if (kring->ring->avail > 0)
revents |= want_rx;
@ -1269,6 +1513,7 @@ netmap_attach(struct netmap_adapter *na, int num_queues)
WNA(ifp) = buf;
na->tx_rings = (void *)((char *)buf + sizeof(*na));
na->rx_rings = na->tx_rings + n;
na->buff_size = NETMAP_BUF_SIZE;
bcopy(na, buf, sizeof(*na));
ifp->if_capabilities |= IFCAP_NETMAP;
}
@ -1399,229 +1644,6 @@ netmap_reset(struct netmap_adapter *na, enum txrx tx, int n,
}
/*------ netmap memory allocator -------*/
/*
* Request for a chunk of memory.
*
* Memory objects are arranged into a list, hence we need to walk this
* list until we find an object with the needed amount of data free.
* This sounds like a completely inefficient implementation, but given
* the fact that data allocation is done once, we can handle it
* flawlessly.
*
* Return NULL on failure.
*/
static void *
netmap_malloc(size_t size, __unused const char *msg)
{
struct netmap_mem_obj *mem_obj, *new_mem_obj;
void *ret = NULL;
NMA_LOCK();
TAILQ_FOREACH(mem_obj, &netmap_mem_d->nm_molist, nmo_next) {
if (mem_obj->nmo_used != 0 || mem_obj->nmo_size < size)
continue;
new_mem_obj = malloc(sizeof(struct netmap_mem_obj), M_NETMAP,
M_WAITOK | M_ZERO);
TAILQ_INSERT_BEFORE(mem_obj, new_mem_obj, nmo_next);
new_mem_obj->nmo_used = 1;
new_mem_obj->nmo_size = size;
new_mem_obj->nmo_data = mem_obj->nmo_data;
memset(new_mem_obj->nmo_data, 0, new_mem_obj->nmo_size);
mem_obj->nmo_size -= size;
mem_obj->nmo_data = (char *) mem_obj->nmo_data + size;
if (mem_obj->nmo_size == 0) {
TAILQ_REMOVE(&netmap_mem_d->nm_molist, mem_obj,
nmo_next);
free(mem_obj, M_NETMAP);
}
ret = new_mem_obj->nmo_data;
break;
}
NMA_UNLOCK();
ND("%s: %d bytes at %p", msg, size, ret);
return (ret);
}
/*
* Return the memory to the allocator.
*
* While freeing a memory object, we try to merge adjacent chunks in
* order to reduce memory fragmentation.
*/
static void
netmap_free(void *addr, const char *msg)
{
size_t size;
struct netmap_mem_obj *cur, *prev, *next;
if (addr == NULL) {
D("NULL addr for %s", msg);
return;
}
NMA_LOCK();
TAILQ_FOREACH(cur, &netmap_mem_d->nm_molist, nmo_next) {
if (cur->nmo_data == addr && cur->nmo_used)
break;
}
if (cur == NULL) {
NMA_UNLOCK();
D("invalid addr %s %p", msg, addr);
return;
}
size = cur->nmo_size;
cur->nmo_used = 0;
/* merge current chunk of memory with the previous one,
if present. */
prev = TAILQ_PREV(cur, netmap_mem_obj_h, nmo_next);
if (prev && prev->nmo_used == 0) {
TAILQ_REMOVE(&netmap_mem_d->nm_molist, cur, nmo_next);
prev->nmo_size += cur->nmo_size;
free(cur, M_NETMAP);
cur = prev;
}
/* merge with the next one */
next = TAILQ_NEXT(cur, nmo_next);
if (next && next->nmo_used == 0) {
TAILQ_REMOVE(&netmap_mem_d->nm_molist, next, nmo_next);
cur->nmo_size += next->nmo_size;
free(next, M_NETMAP);
}
NMA_UNLOCK();
ND("freed %s %d bytes at %p", msg, size, addr);
}
/*
* Initialize the memory allocator.
*
* Create the descriptor for the memory , allocate the pool of memory
* and initialize the list of memory objects with a single chunk
* containing the whole pre-allocated memory marked as free.
*
* Start with a large size, then halve as needed if we fail to
* allocate the block. While halving, always add one extra page
* because buffers 0 and 1 are used for special purposes.
* Return 0 on success, errno otherwise.
*/
static int
netmap_memory_init(void)
{
struct netmap_mem_obj *mem_obj;
void *buf = NULL;
int i, n, sz = NETMAP_MEMORY_SIZE;
int extra_sz = 0; // space for rings and two spare buffers
for (; sz >= 1<<20; sz >>=1) {
extra_sz = sz/200;
extra_sz = (extra_sz + 2*PAGE_SIZE - 1) & ~(PAGE_SIZE-1);
buf = contigmalloc(sz + extra_sz,
M_NETMAP,
M_WAITOK | M_ZERO,
0, /* low address */
-1UL, /* high address */
PAGE_SIZE, /* alignment */
0 /* boundary */
);
if (buf)
break;
}
if (buf == NULL)
return (ENOMEM);
sz += extra_sz;
netmap_mem_d = malloc(sizeof(struct netmap_mem_d), M_NETMAP,
M_WAITOK | M_ZERO);
mtx_init(&netmap_mem_d->nm_mtx, "netmap memory allocator lock", NULL,
MTX_DEF);
TAILQ_INIT(&netmap_mem_d->nm_molist);
netmap_mem_d->nm_buffer = buf;
netmap_mem_d->nm_totalsize = sz;
/*
* A buffer takes 2k, a slot takes 8 bytes + ring overhead,
* so the ratio is 200:1. In other words, we can use 1/200 of
* the memory for the rings, and the rest for the buffers,
* and be sure we never run out.
*/
netmap_mem_d->nm_size = sz/200;
netmap_mem_d->nm_buf_start =
(netmap_mem_d->nm_size + PAGE_SIZE - 1) & ~(PAGE_SIZE-1);
netmap_mem_d->nm_buf_len = sz - netmap_mem_d->nm_buf_start;
nm_buf_pool.base = netmap_mem_d->nm_buffer;
nm_buf_pool.base += netmap_mem_d->nm_buf_start;
netmap_buffer_base = nm_buf_pool.base;
D("netmap_buffer_base %p (offset %d)",
netmap_buffer_base, (int)netmap_mem_d->nm_buf_start);
/* number of buffers, they all start as free */
netmap_total_buffers = nm_buf_pool.total_buffers =
netmap_mem_d->nm_buf_len / NETMAP_BUF_SIZE;
nm_buf_pool.bufsize = NETMAP_BUF_SIZE;
D("Have %d MB, use %dKB for rings, %d buffers at %p",
(sz >> 20), (int)(netmap_mem_d->nm_size >> 10),
nm_buf_pool.total_buffers, nm_buf_pool.base);
/* allocate and initialize the bitmap. Entry 0 is considered
* always busy (used as default when there are no buffers left).
*/
n = (nm_buf_pool.total_buffers + 31) / 32;
nm_buf_pool.bitmap = malloc(sizeof(uint32_t) * n, M_NETMAP,
M_WAITOK | M_ZERO);
nm_buf_pool.bitmap[0] = ~3; /* slot 0 and 1 always busy */
for (i = 1; i < n; i++)
nm_buf_pool.bitmap[i] = ~0;
nm_buf_pool.free = nm_buf_pool.total_buffers - 2;
mem_obj = malloc(sizeof(struct netmap_mem_obj), M_NETMAP,
M_WAITOK | M_ZERO);
TAILQ_INSERT_HEAD(&netmap_mem_d->nm_molist, mem_obj, nmo_next);
mem_obj->nmo_used = 0;
mem_obj->nmo_size = netmap_mem_d->nm_size;
mem_obj->nmo_data = netmap_mem_d->nm_buffer;
return (0);
}
/*
* Finalize the memory allocator.
*
* Free all the memory objects contained inside the list, and deallocate
* the pool of memory; finally free the memory allocator descriptor.
*/
static void
netmap_memory_fini(void)
{
struct netmap_mem_obj *mem_obj;
while (!TAILQ_EMPTY(&netmap_mem_d->nm_molist)) {
mem_obj = TAILQ_FIRST(&netmap_mem_d->nm_molist);
TAILQ_REMOVE(&netmap_mem_d->nm_molist, mem_obj, nmo_next);
if (mem_obj->nmo_used == 1) {
printf("netmap: leaked %d bytes at %p\n",
(int)mem_obj->nmo_size,
mem_obj->nmo_data);
}
free(mem_obj, M_NETMAP);
}
contigfree(netmap_mem_d->nm_buffer, netmap_mem_d->nm_totalsize, M_NETMAP);
// XXX mutex_destroy(nm_mtx);
free(netmap_mem_d, M_NETMAP);
}
/*
* Module loader.
*

12
sys/dev/netmap/netmap_kern.h
View File

@ -172,8 +172,10 @@ struct netmap_slot *netmap_reset(struct netmap_adapter *na,
enum txrx tx, int n, u_int new_cur);
int netmap_ring_reinit(struct netmap_kring *);
extern int netmap_buf_size;
#define NETMAP_BUF_SIZE netmap_buf_size
extern int netmap_mitigate;
extern int netmap_skip_txsync, netmap_skip_rxsync;
extern int netmap_no_pendintr;
extern u_int netmap_total_buffers;
extern char *netmap_buffer_base;
extern int netmap_verbose; // XXX debugging
@ -236,11 +238,7 @@ NMB(struct netmap_slot *slot)
{
uint32_t i = slot->buf_idx;
return (i >= netmap_total_buffers) ? netmap_buffer_base :
#if NETMAP_BUF_SIZE == 2048
netmap_buffer_base + (i << 11);
#else
netmap_buffer_base + (i *NETMAP_BUF_SIZE);
#endif
}
static inline void *
@ -248,11 +246,7 @@ PNMB(struct netmap_slot *slot, uint64_t *pp)
{
uint32_t i = slot->buf_idx;
void *ret = (i >= netmap_total_buffers) ? netmap_buffer_base :
#if NETMAP_BUF_SIZE == 2048
netmap_buffer_base + (i << 11);
#else
netmap_buffer_base + (i *NETMAP_BUF_SIZE);
#endif
*pp = vtophys(ret);
return ret;
}

6
sys/net/netmap.h
View File

@ -258,12 +258,6 @@ struct nmreq {
#define NETMAP_RING_MASK 0xfff /* the ring number */
};
/*
* default buf size is 2048, but it may make sense to have
* it shorter for better cache usage.
*/
#define NETMAP_BUF_SIZE (2048)
#define NIOCGINFO _IOWR('i', 145, struct nmreq) /* return IF info */
#define NIOCREGIF _IOWR('i', 146, struct nmreq) /* interface register */
#define NIOCUNREGIF _IO('i', 147) /* interface unregister */

8
sys/net/netmap_user.h
View File

@ -73,14 +73,8 @@
((struct netmap_ring *)((char *)(nifp) + \
(nifp)->ring_ofs[index + (nifp)->ni_num_queues+1] ) )
#if NETMAP_BUF_SIZE != 2048
#error cannot handle odd size
#define NETMAP_BUF(ring, index) \
((char *)(ring) + (ring)->buf_ofs + ((index)*NETMAP_BUF_SIZE))
#else
#define NETMAP_BUF(ring, index) \
((char *)(ring) + (ring)->buf_ofs + ((index)<<11))
#endif
((char *)(ring) + (ring)->buf_ofs + ((index)*(ring)->nr_buf_size))
#define NETMAP_RING_NEXT(r, i) \
((i)+1 == (r)->num_slots ? 0 : (i) + 1 )

2
tools/tools/netmap/pkt-gen.c
View File

@ -124,7 +124,7 @@ struct pkt {
struct ether_header eh;
struct ip ip;
struct udphdr udp;
uint8_t body[NETMAP_BUF_SIZE];
uint8_t body[2048]; // XXX hardwired
} __attribute__((__packed__));
/*