| Message ID | 1345631207.6821.140.camel@zakaz.uk.xensource.com |
|---|---|
| State | Accepted, archived |
| Delegated to: | David Miller |
| Headers | show |
On Wed, Aug 22, 2012 at 11:26:47AM +0100, Ian Campbell wrote: > On Wed, 2012-08-08 at 23:50 +0100, David Miller wrote: > > Just use something like a call to __pskb_pull_tail(skb, len) and all > > that other crap around that area can simply be deleted. > > I think you mean something like this, which works for me, although I've > only lightly tested it. > I've tested it heavily and works great. Tested-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> and I took a look at it too and: Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> > Ian. > > 8<---------------------------------------- > > >From 9e47e3e87a33b45974448649a97859a479183041 Mon Sep 17 00:00:00 2001 > From: Ian Campbell <ian.campbell@citrix.com> > Date: Wed, 22 Aug 2012 10:15:29 +0100 > Subject: [PATCH] xen-netfront: use __pskb_pull_tail to ensure linear area is big enough on RX > > I'm slightly concerned by the "only in exceptional circumstances" > comment on __pskb_pull_tail but the structure of an skb just created > by netfront shouldn't hit any of the especially slow cases. > > This approach still does slightly more work than the old way, since if > we pull up the entire first frag we now have to shuffle everything > down where before we just received into the right place in the first > place. > > Signed-off-by: Ian Campbell <ian.campbell@citrix.com> > Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> > Cc: Jeremy Fitzhardinge <jeremy@goop.org> > Cc: Mel Gorman <mgorman@suse.de> > Cc: xen-devel@lists.xensource.com > Cc: netdev@vger.kernel.org > Cc: linux-kernel@vger.kernel.org > --- > drivers/net/xen-netfront.c | 39 ++++++++++----------------------------- > 1 files changed, 10 insertions(+), 29 deletions(-) > > diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c > index 3089990..650f79a 100644 > --- a/drivers/net/xen-netfront.c > +++ b/drivers/net/xen-netfront.c > @@ -57,8 +57,7 @@ > static const struct ethtool_ops xennet_ethtool_ops; > > struct netfront_cb { > - struct page *page; > - unsigned offset; > + int pull_to; > }; > > #define NETFRONT_SKB_CB(skb) ((struct netfront_cb *)((skb)->cb)) > @@ -867,15 +866,9 @@ static int handle_incoming_queue(struct net_device *dev, > struct sk_buff *skb; > > while ((skb = __skb_dequeue(rxq)) != NULL) { > - struct page *page = NETFRONT_SKB_CB(skb)->page; > - void *vaddr = page_address(page); > - unsigned offset = NETFRONT_SKB_CB(skb)->offset; > - > - memcpy(skb->data, vaddr + offset, > - skb_headlen(skb)); > + int pull_to = NETFRONT_SKB_CB(skb)->pull_to; > > - if (page != skb_frag_page(&skb_shinfo(skb)->frags[0])) > - __free_page(page); > + __pskb_pull_tail(skb, pull_to - skb_headlen(skb)); > > /* Ethernet work: Delayed to here as it peeks the header. */ > skb->protocol = eth_type_trans(skb, dev); > @@ -913,7 +906,6 @@ static int xennet_poll(struct napi_struct *napi, int budget) > struct sk_buff_head errq; > struct sk_buff_head tmpq; > unsigned long flags; > - unsigned int len; > int err; > > spin_lock(&np->rx_lock); > @@ -955,24 +947,13 @@ err: > } > } > > - NETFRONT_SKB_CB(skb)->page = > - skb_frag_page(&skb_shinfo(skb)->frags[0]); > - NETFRONT_SKB_CB(skb)->offset = rx->offset; > - > - len = rx->status; > - if (len > RX_COPY_THRESHOLD) > - len = RX_COPY_THRESHOLD; > - skb_put(skb, len); > + NETFRONT_SKB_CB(skb)->pull_to = rx->status; > + if (NETFRONT_SKB_CB(skb)->pull_to > RX_COPY_THRESHOLD) > + NETFRONT_SKB_CB(skb)->pull_to = RX_COPY_THRESHOLD; > > - if (rx->status > len) { > - skb_shinfo(skb)->frags[0].page_offset = > - rx->offset + len; > - skb_frag_size_set(&skb_shinfo(skb)->frags[0], rx->status - len); > - skb->data_len = rx->status - len; > - } else { > - __skb_fill_page_desc(skb, 0, NULL, 0, 0); > - skb_shinfo(skb)->nr_frags = 0; > - } > + skb_shinfo(skb)->frags[0].page_offset = rx->offset; > + skb_frag_size_set(&skb_shinfo(skb)->frags[0], rx->status); > + skb->data_len = rx->status; > > i = xennet_fill_frags(np, skb, &tmpq); > > @@ -999,7 +980,7 @@ err: > * receive throughout using the standard receive > * buffer size was cut by 25%(!!!). > */ > - skb->truesize += skb->data_len - (RX_COPY_THRESHOLD - len); > + skb->truesize += skb->data_len - RX_COPY_THRESHOLD; > skb->len += skb->data_len; > > if (rx->flags & XEN_NETRXF_csum_blank) > -- > 1.7.2.5 > > > > -- > To unsubscribe, send a message with 'unsubscribe linux-mm' in > the body to majordomo@kvack.org. For more info on Linux MM, > see: http://www.linux-mm.org/ . > Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> > -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
From: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Date: Thu, 23 Aug 2012 10:17:40 -0400 > On Wed, Aug 22, 2012 at 11:26:47AM +0100, Ian Campbell wrote: >> On Wed, 2012-08-08 at 23:50 +0100, David Miller wrote: >> > Just use something like a call to __pskb_pull_tail(skb, len) and all >> > that other crap around that area can simply be deleted. >> >> I think you mean something like this, which works for me, although I've >> only lightly tested it. >> > > I've tested it heavily and works great. > > Tested-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> > and I took a look at it too and: > > Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Applied, thanks everyone. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c index 3089990..650f79a 100644 --- a/drivers/net/xen-netfront.c +++ b/drivers/net/xen-netfront.c @@ -57,8 +57,7 @@ static const struct ethtool_ops xennet_ethtool_ops; struct netfront_cb { - struct page *page; - unsigned offset; + int pull_to; }; #define NETFRONT_SKB_CB(skb) ((struct netfront_cb *)((skb)->cb)) @@ -867,15 +866,9 @@ static int handle_incoming_queue(struct net_device *dev, struct sk_buff *skb; while ((skb = __skb_dequeue(rxq)) != NULL) { - struct page *page = NETFRONT_SKB_CB(skb)->page; - void *vaddr = page_address(page); - unsigned offset = NETFRONT_SKB_CB(skb)->offset; - - memcpy(skb->data, vaddr + offset, - skb_headlen(skb)); + int pull_to = NETFRONT_SKB_CB(skb)->pull_to; - if (page != skb_frag_page(&skb_shinfo(skb)->frags[0])) - __free_page(page); + __pskb_pull_tail(skb, pull_to - skb_headlen(skb)); /* Ethernet work: Delayed to here as it peeks the header. */ skb->protocol = eth_type_trans(skb, dev); @@ -913,7 +906,6 @@ static int xennet_poll(struct napi_struct *napi, int budget) struct sk_buff_head errq; struct sk_buff_head tmpq; unsigned long flags; - unsigned int len; int err; spin_lock(&np->rx_lock); @@ -955,24 +947,13 @@ err: } } - NETFRONT_SKB_CB(skb)->page = - skb_frag_page(&skb_shinfo(skb)->frags[0]); - NETFRONT_SKB_CB(skb)->offset = rx->offset; - - len = rx->status; - if (len > RX_COPY_THRESHOLD) - len = RX_COPY_THRESHOLD; - skb_put(skb, len); + NETFRONT_SKB_CB(skb)->pull_to = rx->status; + if (NETFRONT_SKB_CB(skb)->pull_to > RX_COPY_THRESHOLD) + NETFRONT_SKB_CB(skb)->pull_to = RX_COPY_THRESHOLD; - if (rx->status > len) { - skb_shinfo(skb)->frags[0].page_offset = - rx->offset + len; - skb_frag_size_set(&skb_shinfo(skb)->frags[0], rx->status - len); - skb->data_len = rx->status - len; - } else { - __skb_fill_page_desc(skb, 0, NULL, 0, 0); - skb_shinfo(skb)->nr_frags = 0; - } + skb_shinfo(skb)->frags[0].page_offset = rx->offset; + skb_frag_size_set(&skb_shinfo(skb)->frags[0], rx->status); + skb->data_len = rx->status; i = xennet_fill_frags(np, skb, &tmpq); @@ -999,7 +980,7 @@ err: * receive throughout using the standard receive * buffer size was cut by 25%(!!!). */ - skb->truesize += skb->data_len - (RX_COPY_THRESHOLD - len); + skb->truesize += skb->data_len - RX_COPY_THRESHOLD; skb->len += skb->data_len; if (rx->flags & XEN_NETRXF_csum_blank)