From 3958fb34ef18529c1e4a3eca44b7aaf94d4f4697 Mon Sep 17 00:00:00 2001 From: Samuel Ortiz Date: Mon, 15 Jan 2007 19:37:25 -0800 Subject: [PATCH] [IrDA]: irda-usb TX path optimization (was Re: IrDA spams logfiles - since 2.6.19) Since we stop using dev_alloc_skb on the IrDA TX frame, we constantly run into the case of the skb headroom being 0, and thus we call skb_cow for every IrDA TX frame. This patch uses a local buffer and memcpy the skb to it, saving us a kmalloc for each of those IrDA TX frames. Signed-off-by: Samuel Ortiz Signed-off-by: David S. Miller --- drivers/net/irda/irda-usb.c | 43 +++++++++++++++++-------------------- drivers/net/irda/irda-usb.h | 1 + 2 files changed, 21 insertions(+), 23 deletions(-) diff --git a/drivers/net/irda/irda-usb.c b/drivers/net/irda/irda-usb.c index 3ca1082ec77..80cbf3f8043 100644 --- a/drivers/net/irda/irda-usb.c +++ b/drivers/net/irda/irda-usb.c @@ -441,25 +441,13 @@ static int irda_usb_hard_xmit(struct sk_buff *skb, struct net_device *netdev) goto drop; } - /* Make sure there is room for IrDA-USB header. The actual - * allocation will be done lower in skb_push(). - * Also, we don't use directly skb_cow(), because it require - * headroom >= 16, which force unnecessary copies - Jean II */ - if (skb_headroom(skb) < self->header_length) { - IRDA_DEBUG(0, "%s(), Insuficient skb headroom.\n", __FUNCTION__); - if (skb_cow(skb, self->header_length)) { - IRDA_WARNING("%s(), failed skb_cow() !!!\n", __FUNCTION__); - goto drop; - } - } + memcpy(self->tx_buff + self->header_length, skb->data, skb->len); /* Change setting for next frame */ - if (self->capability & IUC_STIR421X) { __u8 turnaround_time; - __u8* frame; + __u8* frame = self->tx_buff; turnaround_time = get_turnaround_time( skb ); - frame= skb_push(skb, self->header_length); irda_usb_build_header(self, frame, 0); frame[2] = turnaround_time; if ((skb->len != 0) && @@ -472,17 +460,17 @@ static int irda_usb_hard_xmit(struct sk_buff *skb, struct net_device *netdev) frame[1] = 0; } } else { - irda_usb_build_header(self, skb_push(skb, self->header_length), 0); + irda_usb_build_header(self, self->tx_buff, 0); } /* FIXME: Make macro out of this one */ ((struct irda_skb_cb *)skb->cb)->context = self; - usb_fill_bulk_urb(urb, self->usbdev, + usb_fill_bulk_urb(urb, self->usbdev, usb_sndbulkpipe(self->usbdev, self->bulk_out_ep), - skb->data, IRDA_SKB_MAX_MTU, + self->tx_buff, skb->len + self->header_length, write_bulk_callback, skb); - urb->transfer_buffer_length = skb->len; + /* This flag (URB_ZERO_PACKET) indicates that what we send is not * a continuous stream of data but separate packets. * In this case, the USB layer will insert an empty USB frame (TD) @@ -1455,6 +1443,9 @@ static inline void irda_usb_close(struct irda_usb_cb *self) /* Remove the speed buffer */ kfree(self->speed_buff); self->speed_buff = NULL; + + kfree(self->tx_buff); + self->tx_buff = NULL; } /********************** USB CONFIG SUBROUTINES **********************/ @@ -1753,9 +1744,14 @@ static int irda_usb_probe(struct usb_interface *intf, memset(self->speed_buff, 0, IRDA_USB_SPEED_MTU); + self->tx_buff = kzalloc(IRDA_SKB_MAX_MTU + self->header_length, + GFP_KERNEL); + if (self->tx_buff == NULL) + goto err_out_4; + ret = irda_usb_open(self); if (ret) - goto err_out_4; + goto err_out_5; IRDA_MESSAGE("IrDA: Registered device %s\n", net->name); usb_set_intfdata(intf, self); @@ -1766,14 +1762,14 @@ static int irda_usb_probe(struct usb_interface *intf, self->needspatch = (ret < 0); if (self->needspatch) { IRDA_ERROR("STIR421X: Couldn't upload patch\n"); - goto err_out_5; + goto err_out_6; } /* replace IrDA class descriptor with what patched device is now reporting */ irda_desc = irda_usb_find_class_desc (self->usbintf); if (irda_desc == NULL) { ret = -ENODEV; - goto err_out_5; + goto err_out_6; } if (self->irda_desc) kfree (self->irda_desc); @@ -1782,9 +1778,10 @@ static int irda_usb_probe(struct usb_interface *intf, } return 0; - -err_out_5: +err_out_6: unregister_netdev(self->netdev); +err_out_5: + kfree(self->tx_buff); err_out_4: kfree(self->speed_buff); err_out_3: diff --git a/drivers/net/irda/irda-usb.h b/drivers/net/irda/irda-usb.h index 6b2271f18e7..e846c38224a 100644 --- a/drivers/net/irda/irda-usb.h +++ b/drivers/net/irda/irda-usb.h @@ -156,6 +156,7 @@ struct irda_usb_cb { struct irlap_cb *irlap; /* The link layer we are binded to */ struct qos_info qos; char *speed_buff; /* Buffer for speed changes */ + char *tx_buff; struct timeval stamp; struct timeval now; -- 2.41.0