adulau/aha
1
0
Fork 0
mirror of https://github.com/adulau/aha.git synced 2024-12-28 19:56:18 +00:00
Code Issues Projects Releases Packages Wiki Activity

f_phonet: use page-sized rather than MTU-sized RX buffers

Browse source 
Instead of a large (physically) linear buffer, we generate a set of
paged sk_buff, so no extra memory copy is involved. This removes
high-order allocations and saves quite a bit of memory. Phonet MTU is
65541 bytes, so the two buffers were padded to 128 kilo-bytes each.
Now, we create 17 page buffers, almost a 75% memory use reduction.

Signed-off-by: Rémi Denis-Courmont <remi.denis-courmont@nokia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Rémi Denis-Courmont 2009-08-06 21:56:44 +00:00 committed by David S. Miller
parent 5da63cc4b2
commit b91cd14408
1 changed files with 51 additions and 26 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

77
drivers/usb/gadget/f_phonet.c
View file

@ -35,6 +35,10 @@
#include "u_phonet.h" #include "u_phonet.h"
#define PN_MEDIA_USB 0x1B #define PN_MEDIA_USB 0x1B
#define MAXPACKET 512
#if (PAGE_SIZE % MAXPACKET)
#error MAXPACKET must divide PAGE_SIZE!
#endif
/*-------------------------------------------------------------------------*/ /*-------------------------------------------------------------------------*/
@ -45,6 +49,10 @@ struct phonet_port {
struct f_phonet { struct f_phonet {
struct usb_function function; struct usb_function function;
struct {
struct sk_buff *skb;
spinlock_t lock;
} rx;
struct net_device *dev; struct net_device *dev;
struct usb_ep *in_ep, *out_ep; struct usb_ep *in_ep, *out_ep;
@ -52,7 +60,7 @@ struct f_phonet {
struct usb_request *out_reqv[0]; struct usb_request *out_reqv[0];
}; };
static int phonet_rxq_size = 2; static int phonet_rxq_size = 17;
static inline struct f_phonet *func_to_pn(struct usb_function *f) static inline struct f_phonet *func_to_pn(struct usb_function *f)
{ {
@ -138,7 +146,7 @@ pn_hs_sink_desc = {
.bEndpointAddress = USB_DIR_OUT, .bEndpointAddress = USB_DIR_OUT,
.bmAttributes = USB_ENDPOINT_XFER_BULK, .bmAttributes = USB_ENDPOINT_XFER_BULK,
.wMaxPacketSize = cpu_to_le16(512), .wMaxPacketSize = cpu_to_le16(MAXPACKET),
}; };
static struct usb_endpoint_descriptor static struct usb_endpoint_descriptor
@ -298,21 +306,21 @@ static void pn_net_setup(struct net_device *dev)
static int static int
pn_rx_submit(struct f_phonet *fp, struct usb_request *req, gfp_t gfp_flags) pn_rx_submit(struct f_phonet *fp, struct usb_request *req, gfp_t gfp_flags)
{ {
struct sk_buff *skb; struct net_device *dev = fp->dev;
const size_t size = fp->dev->mtu; struct page *page;
int err; int err;
skb = alloc_skb(size, gfp_flags); page = __netdev_alloc_page(dev, gfp_flags);
if (!skb) if (!page)
return -ENOMEM; return -ENOMEM;
req->buf = skb->data; req->buf = page_address(page);
req->length = size; req->length = PAGE_SIZE;
req->context = skb; req->context = page;
err = usb_ep_queue(fp->out_ep, req, gfp_flags); err = usb_ep_queue(fp->out_ep, req, gfp_flags);
if (unlikely(err)) if (unlikely(err))
dev_kfree_skb_any(skb); netdev_free_page(dev, page);
return err; return err;
} }
@ -320,25 +328,37 @@ static void pn_rx_complete(struct usb_ep *ep, struct usb_request *req)
{ {
struct f_phonet *fp = ep->driver_data; struct f_phonet *fp = ep->driver_data;
struct net_device *dev = fp->dev; struct net_device *dev = fp->dev;
struct sk_buff *skb = req->context; struct page *page = req->context;
struct sk_buff *skb;
unsigned long flags;
int status = req->status; int status = req->status;
switch (status) { switch (status) {
case 0: case 0:
if (unlikely(!netif_running(dev))) spin_lock_irqsave(&fp->rx.lock, flags);
break; skb = fp->rx.skb;
if (unlikely(req->actual < 1)) if (!skb)
break; skb = fp->rx.skb = netdev_alloc_skb(dev, 12);
skb_put(skb, req->actual); if (req->actual < req->length) /* Last fragment */
skb->protocol = htons(ETH_P_PHONET); fp->rx.skb = NULL;
skb_reset_mac_header(skb); spin_unlock_irqrestore(&fp->rx.lock, flags);
__skb_pull(skb, 1);
skb->dev = dev;
dev->stats.rx_packets++;
dev->stats.rx_bytes += skb->len;
netif_rx(skb); if (unlikely(!skb))
skb = NULL; break;
skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, page, 0,
req->actual);
page = NULL;
if (req->actual < req->length) { /* Last fragment */
skb->protocol = htons(ETH_P_PHONET);
skb_reset_mac_header(skb);
pskb_pull(skb, 1);
skb->dev = dev;
dev->stats.rx_packets++;
dev->stats.rx_bytes += skb->len;
netif_rx(skb);
}
break; break;
/* Do not resubmit in these cases: */ /* Do not resubmit in these cases: */
@ -356,8 +376,8 @@ static void pn_rx_complete(struct usb_ep *ep, struct usb_request *req)
break; break;
} }
if (skb) if (page)
dev_kfree_skb_any(skb); netdev_free_page(dev, page);
if (req) if (req)
pn_rx_submit(fp, req, GFP_ATOMIC); pn_rx_submit(fp, req, GFP_ATOMIC);
} }
@ -375,6 +395,10 @@ static void __pn_reset(struct usb_function *f)
usb_ep_disable(fp->out_ep); usb_ep_disable(fp->out_ep);
usb_ep_disable(fp->in_ep); usb_ep_disable(fp->in_ep);
if (fp->rx.skb) {
dev_kfree_skb_irq(fp->rx.skb);
fp->rx.skb = NULL;
}
} }
static int pn_set_alt(struct usb_function *f, unsigned intf, unsigned alt) static int pn_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
@ -573,6 +597,7 @@ int __init phonet_bind_config(struct usb_configuration *c)
fp->function.set_alt = pn_set_alt; fp->function.set_alt = pn_set_alt;
fp->function.get_alt = pn_get_alt; fp->function.get_alt = pn_get_alt;
fp->function.disable = pn_disconnect; fp->function.disable = pn_disconnect;
spin_lock_init(&fp->rx.lock);
err = usb_add_function(c, &fp->function); err = usb_add_function(c, &fp->function);
if (err) if (err)