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bitkeeper revision 1.1159.96.1 (415ab5b3EClFFrtIHoI6XpNdO3uguQ)

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Reduce burstiness of allocations in netfront driver. Also set a
fill traget for the receive ring which is as small as possible without
dropping packets.
This commit is contained in:
kaf24@freefall.cl.cam.ac.uk committed 2004-09-29 13:16:35 +00:00
1 parent 0182d31a2a
commit fc0d7e490c
1 file changed
+161 -130
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linux-2.6.8.1-xen-sparse/drivers/xen/netfront/netfront.c
+161 -130
View File
@@ -31,22 +31,6 @@
#define DEBUG 0
#if DEBUG
#define DPRINTK(fmt, args...) \
printk(KERN_INFO "[XEN] %s" fmt, __FUNCTION__, ##args)
#else
#define DPRINTK(fmt, args...) ((void)0)
#endif
#define IPRINTK(fmt, args...) \
printk(KERN_INFO "[XEN]" fmt, ##args)
#define WPRINTK(fmt, args...) \
printk(KERN_WARNING "[XEN]" fmt, ##args)
#define EPRINTK(fmt, args...) \
printk(KERN_ERROR "[XEN]" fmt, ##args)
#ifndef __GFP_NOWARN
#define __GFP_NOWARN 0
#endif
@@ -114,6 +98,12 @@ struct net_private
#define UST_OPEN 1
unsigned int user_state;
/* Receive-ring batched refills. */
#define RX_MIN_TARGET 8
#define RX_MAX_TARGET NETIF_RX_RING_SIZE
int rx_target;
struct sk_buff_head rx_batch;
/*
* {tx,rx}_skbs store outstanding skbuffs. The first entry in each
* array is an index into a chain of free entries.
@@ -122,24 +112,6 @@ struct net_private
struct sk_buff *rx_skbs[NETIF_RX_RING_SIZE+1];
};
char * status_name[] = {
[NETIF_INTERFACE_STATUS_CLOSED] = "closed",
[NETIF_INTERFACE_STATUS_DISCONNECTED] = "disconnected",
[NETIF_INTERFACE_STATUS_CONNECTED] = "connected",
[NETIF_INTERFACE_STATUS_CHANGED] = "changed",
};
char * be_state_name[] = {
[BEST_CLOSED] = "closed",
[BEST_DISCONNECTED] = "disconnected",
[BEST_CONNECTED] = "connected",
};
char * user_state_name[] = {
[UST_CLOSED] = "closed",
[UST_OPEN] = "open",
};
/* Access macros for acquiring freeing slots in {tx,rx}_skbs[]. */
#define ADD_ID_TO_FREELIST(_list, _id) \
(_list)[(_id)] = (_list)[0]; \
@@ -149,6 +121,30 @@ char * user_state_name[] = {
(_list)[0] = (_list)[_id]; \
(unsigned short)_id; })
static char *status_name[] = {
[NETIF_INTERFACE_STATUS_CLOSED] = "closed",
[NETIF_INTERFACE_STATUS_DISCONNECTED] = "disconnected",
[NETIF_INTERFACE_STATUS_CONNECTED] = "connected",
[NETIF_INTERFACE_STATUS_CHANGED] = "changed",
};
static char *be_state_name[] = {
[BEST_CLOSED] = "closed",
[BEST_DISCONNECTED] = "disconnected",
[BEST_CONNECTED] = "connected",
};
#if DEBUG
#define DPRINTK(fmt, args...) \
printk(KERN_ALERT "[XEN] (%s:%d) " fmt, __FUNCTION__, __LINE__, ##args)
#else
#define DPRINTK(fmt, args...) ((void)0)
#endif
#define IPRINTK(fmt, args...) \
printk(KERN_INFO "[XEN] " fmt, ##args)
#define WPRINTK(fmt, args...) \
printk(KERN_WARNING "[XEN] " fmt, ##args)
static struct net_device *find_dev_by_handle(unsigned int handle)
{
struct list_head *ent;
@@ -185,9 +181,8 @@ static void netctrl_init(void)
*/
static int netctrl_err(int err)
{
if ( (err < 0) && !netctrl.err ){
if ( (err < 0) && !netctrl.err )
netctrl.err = err;
}
return netctrl.err;
}
@@ -197,13 +192,15 @@ static int netctrl_err(int err)
*/
static int netctrl_connected(void)
{
int ok = 0;
int ok;
if(netctrl.err){
if ( netctrl.err )
ok = netctrl.err;
} else if(netctrl.up == NETIF_DRIVER_STATUS_UP){
else if ( netctrl.up == NETIF_DRIVER_STATUS_UP )
ok = (netctrl.connected_n == netctrl.interface_n);
}
else
ok = 0;
return ok;
}
@@ -222,9 +219,8 @@ static int netctrl_connected_count(void)
list_for_each(ent, &dev_list) {
np = list_entry(ent, struct net_private, list);
if (np->backend_state == BEST_CONNECTED){
if (np->backend_state == BEST_CONNECTED)
connected++;
}
}
netctrl.connected_n = connected;
@@ -326,17 +322,34 @@ static void network_alloc_rx_buffers(struct net_device *dev)
unsigned short id;
struct net_private *np = dev->priv;
struct sk_buff *skb;
NETIF_RING_IDX i = np->rx->req_prod;
int nr_pfns = 0;
int i, batch_target;
NETIF_RING_IDX req_prod = np->rx->req_prod;
/* Make sure the batch is large enough to be worthwhile (1/2 ring). */
if ( unlikely((i - np->rx_resp_cons) > (NETIF_RX_RING_SIZE/2)) ||
unlikely(np->backend_state != BEST_CONNECTED) )
if ( unlikely(np->backend_state != BEST_CONNECTED) )
return;
do {
/*
* Allocate skbuffs greedily, even though we batch updates to the
* receive ring. This creates a less bursty demand on the memory allocator,
* so should reduce the chance of failed allocation requests both for
* ourself and for other kernel subsystems.
*/
batch_target = np->rx_target - (req_prod - np->rx_resp_cons);
for ( i = skb_queue_len(&np->rx_batch); i < batch_target; i++ )
{
if ( unlikely((skb = alloc_xen_skb(dev->mtu + RX_HEADROOM)) == NULL) )
break;
__skb_queue_tail(&np->rx_batch, skb);
}
/* Is the batch large enough to be worthwhile? */
if ( i < (np->rx_target/2) )
return;
for ( i = 0; ; i++ )
{
if ( (skb = __skb_dequeue(&np->rx_batch)) == NULL )
break;
skb->dev = dev;
@@ -344,25 +357,19 @@ static void network_alloc_rx_buffers(struct net_device *dev)
np->rx_skbs[id] = skb;
np->rx->ring[MASK_NETIF_RX_IDX(i)].req.id = id;
np->rx->ring[MASK_NETIF_RX_IDX(req_prod + i)].req.id = id;
rx_pfn_array[nr_pfns] = virt_to_machine(skb->head) >> PAGE_SHIFT;
rx_pfn_array[i] = virt_to_machine(skb->head) >> PAGE_SHIFT;
/* Remove this page from pseudo phys map before passing back to Xen. */
phys_to_machine_mapping[virt_to_phys(skb->head) >> PAGE_SHIFT]
= INVALID_P2M_ENTRY;
rx_mcl[nr_pfns].op = __HYPERVISOR_update_va_mapping;
rx_mcl[nr_pfns].args[0] = (unsigned long)skb->head >> PAGE_SHIFT;
rx_mcl[nr_pfns].args[1] = 0;
rx_mcl[nr_pfns].args[2] = 0;
nr_pfns++;
rx_mcl[i].op = __HYPERVISOR_update_va_mapping;
rx_mcl[i].args[0] = (unsigned long)skb->head >> PAGE_SHIFT;
rx_mcl[i].args[1] = 0;
rx_mcl[i].args[2] = 0;
}
while ( (++i - np->rx_resp_cons) != NETIF_RX_RING_SIZE );
if ( unlikely(nr_pfns == 0) )
return;
/*
* We may have allocated buffers which have entries outstanding in the page
@@ -371,25 +378,30 @@ static void network_alloc_rx_buffers(struct net_device *dev)
flush_page_update_queue();
/* After all PTEs have been zapped we blow away stale TLB entries. */
rx_mcl[nr_pfns-1].args[2] = UVMF_FLUSH_TLB;
rx_mcl[i-1].args[2] = UVMF_FLUSH_TLB;
/* Give away a batch of pages. */
rx_mcl[nr_pfns].op = __HYPERVISOR_dom_mem_op;
rx_mcl[nr_pfns].args[0] = MEMOP_decrease_reservation;
rx_mcl[nr_pfns].args[1] = (unsigned long)rx_pfn_array;
rx_mcl[nr_pfns].args[2] = (unsigned long)nr_pfns;
rx_mcl[nr_pfns].args[3] = 0;
rx_mcl[nr_pfns].args[4] = DOMID_SELF;
rx_mcl[i].op = __HYPERVISOR_dom_mem_op;
rx_mcl[i].args[0] = MEMOP_decrease_reservation;
rx_mcl[i].args[1] = (unsigned long)rx_pfn_array;
rx_mcl[i].args[2] = (unsigned long)i;
rx_mcl[i].args[3] = 0;
rx_mcl[i].args[4] = DOMID_SELF;
/* Zap PTEs and give away pages in one big multicall. */
(void)HYPERVISOR_multicall(rx_mcl, nr_pfns+1);
(void)HYPERVISOR_multicall(rx_mcl, i+1);
/* Check return status of HYPERVISOR_dom_mem_op(). */
if ( rx_mcl[nr_pfns].args[5] != nr_pfns )
if ( unlikely(rx_mcl[i].args[5] != i) )
panic("Unable to reduce memory reservation\n");
/* Above is a suitable barrier to ensure backend will see requests. */
np->rx->req_prod = i;
np->rx->req_prod = req_prod + i;
/* Adjust our floating fill target if we risked running out of buffers. */
if ( ((req_prod - np->rx->resp_prod) < (np->rx_target / 4)) &&
((np->rx_target *= 2) > RX_MAX_TARGET) )
np->rx_target = RX_MAX_TARGET;
}
@@ -627,6 +639,12 @@ static int netif_poll(struct net_device *dev, int *pbudget)
np->rx_resp_cons = i;
/* If we get a callback with very few responses, reduce fill target. */
/* NB. Note exponential increase, linear decrease. */
if ( ((np->rx->req_prod - np->rx->resp_prod) > ((3*np->rx_target) / 4)) &&
(--np->rx_target < RX_MIN_TARGET) )
np->rx_target = RX_MIN_TARGET;
network_alloc_rx_buffers(dev);
*pbudget -= work_done;
@@ -755,10 +773,10 @@ static void vif_show(struct net_private *np)
{
#if DEBUG
if (np) {
IPRINTK(" <vif handle=%u %s(%s) evtchn=%u irq=%u tx=%p rx=%p>\n",
IPRINTK("<vif handle=%u %s(%s) evtchn=%u irq=%u tx=%p rx=%p>\n",
np->handle,
be_state_name[np->backend_state],
user_state_name[np->user_state],
np->user_state ? "open" : "closed",
np->evtchn,
np->irq,
np->tx,
@@ -806,13 +824,13 @@ static int send_driver_status(int ok)
/* Stop network device and free tx/rx queues and irq.
*/
static void vif_release(struct net_private *np){
static void vif_release(struct net_private *np)
{
/* Stop old i/f to prevent errors whilst we rebuild the state. */
spin_lock_irq(&np->tx_lock);
spin_lock(&np->rx_lock);
netif_stop_queue(np->dev);
//np->backend_state = BEST_DISCONNECTED;
/* np->backend_state = BEST_DISCONNECTED; */
spin_unlock(&np->rx_lock);
spin_unlock_irq(&np->tx_lock);
@@ -827,18 +845,18 @@ static void vif_release(struct net_private *np){
np->tx = NULL;
np->rx = NULL;
}
}
/* Release vif resources and close it down completely.
*/
static void vif_close(struct net_private *np){
static void vif_close(struct net_private *np)
{
DPRINTK(">\n"); vif_show(np);
WPRINTK(" Unexpected netif-CLOSED message in state %s\n",
WPRINTK("Unexpected netif-CLOSED message in state %s\n",
be_state_name[np->backend_state]);
vif_release(np);
np->backend_state = BEST_CLOSED;
//todo: take dev down and free.
/* todo: take dev down and free. */
vif_show(np); DPRINTK("<\n");
}
@@ -873,11 +891,13 @@ static void vif_disconnect(struct net_private *np){
* is initiated by a special "RESET" message - disconnect could
* just mean we're not allowed to use this interface any more.
*/
static void vif_reset(struct net_private *np){
static void
vif_reset(
struct net_private *np)
{
DPRINTK(">\n");
IPRINTK(" Attempting to reconnect network interface: handle=%u\n",
np->handle);
IPRINTK("Attempting to reconnect network interface: handle=%u\n",
np->handle);
vif_release(np);
vif_disconnect(np);
vif_show(np); DPRINTK("<\n");
@@ -887,7 +907,10 @@ static void vif_reset(struct net_private *np){
* Sets the mac and event channel from the message.
* Binds the irq to the event channel.
*/
static void vif_connect(struct net_private *np, netif_fe_interface_status_t *status){
static void
vif_connect(
struct net_private *np, netif_fe_interface_status_t *status)
{
struct net_device *dev = np->dev;
DPRINTK(">\n");
memcpy(dev->dev_addr, status->mac, ETH_ALEN);
@@ -927,13 +950,14 @@ static int create_netdev(int handle, struct net_device **val)
spin_lock_init(&np->tx_lock);
spin_lock_init(&np->rx_lock);
skb_queue_head_init(&np->rx_batch);
np->rx_target = RX_MIN_TARGET;
/* Initialise {tx,rx}_skbs to be a free chain containing every entry. */
for ( i = 0; i <= NETIF_TX_RING_SIZE; i++ ){
for ( i = 0; i <= NETIF_TX_RING_SIZE; i++ )
np->tx_skbs[i] = (void *)(i+1);
}
for ( i = 0; i <= NETIF_RX_RING_SIZE; i++ ){
for ( i = 0; i <= NETIF_RX_RING_SIZE; i++ )
np->rx_skbs[i] = (void *)(i+1);
}
dev->open = network_open;
dev->hard_start_xmit = network_start_xmit;
@@ -951,11 +975,10 @@ static int create_netdev(int handle, struct net_device **val)
list_add(&np->list, &dev_list);
exit:
if ( (err != 0) && (dev != NULL ) ){
if ( (err != 0) && (dev != NULL ) )
kfree(dev);
} else if ( val != NULL ) {
else if ( val != NULL )
*val = dev;
}
return err;
}
@@ -967,44 +990,42 @@ static int create_netdev(int handle, struct net_device **val)
* @param np return parameter for interface state
* @return 0 on success, error code otherwise
*/
static int target_vif(netif_fe_interface_status_t *status, struct net_private **np)
static int
target_vif(
netif_fe_interface_status_t *status, struct net_private **np)
{
int err = 0;
struct net_device *dev;
DPRINTK("> handle=%d\n", status->handle);
if(status->handle < 0) {
if ( status->handle < 0 )
{
err = -EINVAL;
goto exit;
}
dev = find_dev_by_handle(status->handle);
DPRINTK("> dev=%p\n", dev);
if(dev) goto exit;
// No good - give up.
if(status->status == NETIF_INTERFACE_STATUS_CLOSED) goto exit;
if(status->status == NETIF_INTERFACE_STATUS_CHANGED) goto exit;
// It's a new interface in a good state - create it.
if ( (dev = find_dev_by_handle(status->handle)) != NULL )
goto exit;
if ( status->status == NETIF_INTERFACE_STATUS_CLOSED )
goto exit;
if ( status->status == NETIF_INTERFACE_STATUS_CHANGED )
goto exit;
/* It's a new interface in a good state - create it. */
DPRINTK("> create device...\n");
err = create_netdev(status->handle, &dev);
if(err) goto exit;
if ( (err = create_netdev(status->handle, &dev)) != 0 )
goto exit;
netctrl.interface_n++;
exit:
if(np){
if ( np != NULL )
*np = ((dev && !err) ? dev->priv : NULL);
}
DPRINTK("< err=%d\n", err);
return err;
}
/* Warn about an unexpected status. */
static void unexpected(struct net_private *np,
netif_fe_interface_status_t *status)
{
WPRINTK(" Unexpected netif status %s in state %s\n",
status_name[status->status],
be_state_name[np->backend_state]);
}
/* Handle an interface status message. */
static void netif_interface_status(netif_fe_interface_status_t *status)
{
@@ -1012,22 +1033,25 @@ static void netif_interface_status(netif_fe_interface_status_t *status)
struct net_private *np = NULL;
DPRINTK(">\n");
DPRINTK("> status=%s handle=%d\n", status_name[status->status], status->handle);
DPRINTK("> status=%s handle=%d\n",
status_name[status->status], status->handle);
err = target_vif(status, &np);
if(err){
WPRINTK(" Invalid netif: handle=%u\n", status->handle);
if ( (err = target_vif(status, &np)) != 0 )
{
WPRINTK("Invalid netif: handle=%u\n", status->handle);
return;
}
if(np == NULL){
if ( np == NULL )
{
DPRINTK("> no vif\n");
return;
}
DPRINTK(">\n"); vif_show(np);
switch (status->status) {
switch ( status->status )
{
case NETIF_INTERFACE_STATUS_CLOSED:
switch ( np->backend_state )
{
@@ -1056,7 +1080,9 @@ static void netif_interface_status(netif_fe_interface_status_t *status)
switch ( np->backend_state )
{
case BEST_CLOSED:
unexpected(np, status);
WPRINTK("Unexpected netif status %s in state %s\n",
status_name[status->status],
be_state_name[np->backend_state]);
vif_disconnect(np);
vif_connect(np, status);
break;
@@ -1074,7 +1100,7 @@ static void netif_interface_status(netif_fe_interface_status_t *status)
break;
default:
WPRINTK(" Invalid netif status code %d\n", status->status);
WPRINTK("Invalid netif status code %d\n", status->status);
break;
}
vif_show(np);
@@ -1135,7 +1161,8 @@ static int probe_interfaces(void)
DPRINTK(">\n");
for ( wait_i = 0; wait_i < wait_n; wait_i++) {
for ( wait_i = 0; wait_i < wait_n; wait_i++)
{
DPRINTK("> wait_i=%d\n", wait_i);
conn = netctrl_connected();
if(conn) break;
@@ -1145,9 +1172,10 @@ static int probe_interfaces(void)
}
DPRINTK("> wait finished...\n");
if ( conn <= 0 ) {
if ( conn <= 0 )
{
err = netctrl_err(-ENETDOWN);
WPRINTK(" Failed to connect all virtual interfaces: err=%d\n", err);
WPRINTK("Failed to connect all virtual interfaces: err=%d\n", err);
}
DPRINTK("< err=%d\n", err);
@@ -1177,7 +1205,8 @@ static int probe_interfaces(void)
DPRINTK(">\n");
netctrl.interface_n = 0;
for (wait_i = 0; wait_i < wait_n; wait_i++) {
for ( wait_i = 0; wait_i < wait_n; wait_i++ )
{
DPRINTK("> wait_i=%d query=%d\n", wait_i, query);
msg.handle = query;
memcpy(cmsg.msg, &msg, sizeof(msg));
@@ -1199,9 +1228,10 @@ static int probe_interfaces(void)
}
exit:
if (err) {
if ( err )
{
err = netctrl_err(-ENETDOWN);
WPRINTK(" Connecting virtual network interfaces failed: err=%d\n", err);
WPRINTK("Connecting virtual network interfaces failed: err=%d\n", err);
}
DPRINTK("< err=%d\n", err);
@@ -1218,7 +1248,7 @@ static int __init netif_init(void)
(start_info.flags & SIF_NET_BE_DOMAIN) )
return 0;
IPRINTK(" Initialising virtual ethernet driver.\n");
IPRINTK("Initialising virtual ethernet driver.\n");
INIT_LIST_HEAD(&dev_list);
netctrl_init();
(void)ctrl_if_register_receiver(CMSG_NETIF_FE, netif_ctrlif_rx,
@@ -1277,7 +1307,8 @@ void netif_resume(void)
struct net_private *np;
DPRINTK(">\n");
list_for_each(ent, &dev_list){
list_for_each ( ent, &dev_list )
{
np = list_entry(ent, struct net_private, list);
vif_resume(np);
}
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