It turns out that copying a 16-byte area at ~800k times a second
can be really expensive :) This patch redesigns the frags GRO
interface to avoid copying that area twice.
The two disciples of the frags interface have been converted.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Hi:
gro: Normalise skb before bypassing GRO on netpoll VLAN path
When we detect netpoll RX on the GRO VLAN path we bail out and
call the normal VLAN receive handler. However, the packet needs
to be normalised by calling eth_type_trans since that's what the
normal path expects (normally the GRO path does the fixup).
This patch adds the necessary call to vlan_gro_frags.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Thanks,
Signed-off-by: David S. Miller <davem@davemloft.net>
Jarek Poplawski pointed out that my previous fix is broken for
VLAN+netpoll as if netpoll is enabled we'd end up in the normal
receive path instead of the VLAN receive path.
This patch fixes it by calling the VLAN receive hook.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
As my netpoll fix for net doesn't really work for net-next, we
need this update to move the checks into the right place. As it
stands we may pass freed skbs to netpoll_receive_skb.
This patch also introduces a netpoll_rx_on function to avoid GRO
completely if we're invoked through netpoll. This might seem
paranoid but as netpoll may have an external receive hook it's
better to be safe than sorry. I don't think we need this for
2.6.29 though since there's nothing immediately broken by it.
This patch also moves the GRO_* return values to netdevice.h since
VLAN needs them too (I tried to avoid this originally but alas
this seems to be the easiest way out). This fixes a bug in VLAN
where it continued to use the old return value 2 instead of the
correct GRO_DROP.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
The netpoll entry checks are required to ensure that we don't
receive normal packets when invoked via netpoll. Unfortunately
it only ever worked for the netif_receive_skb/netif_rx entry
points. The VLAN (and subsequently GRO) entry point didn't
have the check and therefore can trigger all sorts of weird
problems.
This patch adds the netpoll check to all entry points.
I'm still uneasy with receiving at all under netpoll (which
apparently is only used by the out-of-tree kdump code). The
reason is it is perfectly legal to receive all data including
headers into highmem if netpoll is off, but if you try to do
that with netpoll on and someone gets a printk in an IRQ handler
you're going to get a nice BUG_ON.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch optimises the Ethernet header comparison to use 2-byte
and 4-byte xors instead of memcmp. In order to facilitate this,
the actual comparison is now carried out by the callers of the
shared dev_gro_receive function.
This has a significant impact when receiving 1500B packets through
10GbE.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Unfortunately simplicity isn't always the best. The fraginfo
interface turned out to be suboptimal. The problem was quite
obvious. For every packet, we have to copy the headers from
the frags structure into skb->head, even though for 99% of the
packets this part is immediately thrown away after the merge.
LRO didn't have this problem because it directly read the headers
from the frags structure.
This patch attempts to address this by creating an interface
that allows GRO to access the headers in the first frag without
having to copy it. Because all drivers that use frags place the
headers in the first frag this optimisation should be enough.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Currently VLAN still has a bit of common code handling the aftermath
of GRO that's shared with the common path. This patch moves them
into shared helpers to reduce code duplication.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
In previous kernels, any kernel module could get access to the
'real-device' and the VLAN-ID for a particular VLAN. In more recent
kernels, the code was restructured such that this is hard to do
without accessing private .h files for any module that cannot use
GPL-only symbols.
Attached is a patch to once again allow non-GPL modules the ability to
access the real-device and VLAN id for VLANs.
Signed-off-by: Ben Greear <greearb@candelatech.com>
Acked-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch adds GRO interfaces for hardware-assisted VLAN reception.
With this in place we're now at parity with LRO as far as the
interface is concerned. That is, you can now take any LRO driver
and convert it over to GRO.
As the CB memory clashes with GRO's use of CB, I've removed it
entirely by storing dev in skb->dev. This is OK because VLAN
gets called first thing in netif_receive_skb and skb->dev is
not used in between us calling netif_rx and netif_receive_skb
getting called.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
The changes to deliver hardware accelerated VLAN packets to packet
sockets (commit bc1d0411) caused a warning for non-NAPI drivers.
The __vlan_hwaccel_rx() function is called directly from the drivers
RX function, for non-NAPI drivers that means its still in RX IRQ
context:
[ 27.779463] ------------[ cut here ]------------
[ 27.779509] WARNING: at kernel/softirq.c:136 local_bh_enable+0x37/0x81()
...
[ 27.782520] [<c0264755>] netif_nit_deliver+0x5b/0x75
[ 27.782590] [<c02bba83>] __vlan_hwaccel_rx+0x79/0x162
[ 27.782664] [<f8851c1d>] atl1_intr+0x9a9/0xa7c [atl1]
[ 27.782738] [<c0155b17>] handle_IRQ_event+0x23/0x51
[ 27.782808] [<c015692e>] handle_edge_irq+0xc2/0x102
[ 27.782878] [<c0105fd5>] do_IRQ+0x4d/0x64
Split hardware accelerated VLAN reception into two parts to fix this:
- __vlan_hwaccel_rx just stores the VLAN TCI and performs the VLAN
device lookup, then calls netif_receive_skb()/netif_rx()
- vlan_hwaccel_do_receive(), which is invoked by netif_receive_skb()
in softirq context, performs the real reception and delivery to
packet sockets.
Reported-and-tested-by: Ramon Casellas <ramon.casellas@cttc.es>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
The generic packet receive code takes care of setting
netdev->last_rx when necessary, for the sake of the
bonding ARP monitor.
Signed-off-by: David S. Miller <davem@davemloft.net>
When VLAN header stripping is used, packets currently bypass packet
sockets (and other network taps) completely. For locally existing
VLANs, they appear directly on the VLAN device, for unknown VLANs
they are silently dropped.
Add a new function netif_nit_deliver() to deliver incoming packets
to all network interface taps and use it in __vlan_hwaccel_rx() to
make VLAN packets visible on the underlying device.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
The VLAN code contains multiple spots that use tag, id and tci as
identifiers for arguments and variables incorrectly and they actually
contain or are expected to contain something different. Additionally
types are used inconsistently (unsigned short vs u16) and identifiers
are sometimes capitalized.
- consistently use u16 for storing TCI, ID or QoS values
- consistently use vlan_id and vlan_tci for storing the respective values
- remove capitalization
- add kdoc comment to netif_hwaccel_{rx,receive_skb}
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Hide struct vlan_dev_info from drivers to prevent them from growing
more creative ways to use it. Provide accessors for the two drivers
that currently use it.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
The function is huge and included at least once in every VLAN acceleration
capable driver. Uninline it; to avoid having drivers depend on the VLAN
module, the function is always built in statically when VLAN is enabled.
With all VLAN acceleration capable drivers that build on x86_64 enabled,
this results in:
text data bss dec hex filename
6515227 854044 343968 7713239 75b1d7 vmlinux.inlined
6505637 854044 343968 7703649 758c61 vmlinux.uninlined
----------------------------------------------------------
-9590
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
