netif_tx_queue_stopped(txq) is most of the time false.
Yet its cost is very expensive on SMP.
static inline int netif_tx_queue_stopped(const struct netdev_queue *dev_queue)
{
return test_bit(__QUEUE_STATE_XOFF, &dev_queue->state);
}
I saw this on oprofile hunting and bnx2 driver bnx2_tx_int().
We probably should split "struct netdev_queue" in two parts, one
being read mostly.
__netif_tx_lock() touches _xmit_lock & xmit_lock_owner, these
deserve a separate cache line.
Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
On a brand new GRO skb, we cannot call ip_hdr since the header
may lie in the non-linear area. This patch adds the helper
skb_gro_network_header to handle this.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
The skb_gro_* code fails to handle the case where a header starts
in the linear area but ends in the frags area. Since the goal
of skb_gro_* is to optimise the case of completely non-linear
packets, we can simply bail out if we have anything in the linear
area.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
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>
The inline function skb_gro_mac_header defined in include/linux/netdevice.h
makes use of page_address(). Depending on configuration options, the latter
is either defined as a macro or is declared as a function in another header
file, namely include/linux/mm.h. However, include/linux/netdevice.h does not
include include/linux/mm.h.
On MIPS, this has produced the following build error:
CC kernel/sysctl_check.o
In file included from include/linux/icmpv6.h:173,
from include/linux/ipv6.h:208,
from include/net/ip_vs.h:26,
from kernel/sysctl_check.c:6:
include/linux/netdevice.h: In function 'skb_gro_mac_header':
include/linux/netdevice.h:1132: error: implicit declaration of function
'page_address'
include/linux/netdevice.h:1133: warning: pointer/integer type mismatch
in conditional expression
make[1]: *** [kernel/sysctl_check.o] Error 1
make: *** [kernel] Error 2
The patch adds the missing include and fixes the build error.
Signed-off-by: Dmitri Vorobiev <dmitri.vorobiev@movial.com>
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>
This adds support to provide Fiber Channel over Ethernet (FCoE) offload
through net_device's net_device_ops struct. The offload through net_device
for FCoE is enabled in kernel as built-in or module driver.
Signed-off-by: Yi Zou <yi.zou@intel.com>
Acked-by: David Miller <davem@davemloft.net>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
As analyzed by Patrick McHardy, vlan needs to reset it's
netdev_ops pointer in it's ->init() function but this
leaves the compat method pointers stale.
Add a netdev_resync_ops() and call it from the vlan code.
Any other driver which changes ->netdev_ops after register_netdevice()
will need to call this new function after doing so too.
With help from Patrick McHardy.
Tested-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Base versions handle constant folding now. For headers exposed to
userspace, we must only expose the __ prefixed versions.
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
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>
This patch prepares for the move of the same_flow checks out of
dev_gro_receive. As such we need to remember the number of held
packets since doing a loop just to count them every time is silly.
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>
Following the removal of the unused struct net_device * parameter from
the NAPI functions named *netif_rx_* in commit 908a7a1, they are
exactly equivalent to the corresponding *napi_* functions and are
therefore redundant.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This adds an init_dummy_netdev() function that gets a network device
structure (allocation and lifetime entirely under caller's control) and
initialize the minimum amount of fields so it can be used to schedule
NAPI polls without registering a full blown interface. This is to be
used by drivers that need to tie several hardware interfaces to a single
NAPI poll scheduler due to HW limitations.
It also updates the ibm_newemac driver to use that, this fixing the
oops on 2.6.29 due to passing NULL as "dev" to netif_napi_add()
Symbol is exported GPL only a I don't think we want binary drivers doing
that sort of acrobatics (if we want them at all).
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Tested-by: Geert Uytterhoeven <Geert.Uytterhoeven@sonycom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
David S. Miller
Eric Dumazet
Jesse Brandeburg
Mike Rapoport
Herbert Xu
Adrian Bunk
Patrick McHardy
Linus Torvalds
Dmitri Vorobiev
Yi Zou
Chris Leech
Harvey Harrison
Graf Yang
Ben Hutchings
Benjamin Herrenschmidt