Le vendredi 17 décembre 2010 à 10:26 +0100, Eric Dumazet a écrit :
>
> I think we can add this after latest Changli patch :
>
> He does one skb_clone() before calling the sniffers.
> We could set timestamp on this clone, instead of original skb.
>
> Problem solved.
>
[PATCH net-next-2.6] net: timestamp cloned packet in dev_queue_xmit_nit
Now we do one clone of skb if at least one sniffer might take packet,
we also can do the skb timestamping on the clone and let original packet
unchanged.
This is a generalization of commit 8caf153974 (net: sch_netem: Fix an
inconsistency in ingress netem timestamps.)
This way, we can have a good idea when packets are delivered to our
stack (tcpdump -i ifb0), while a tcpdump on original device gives
timestamps right before ingressing.
This also speedup our stack, avoiding taking timestamps if not needed.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Changli Gao <xiaosuo@gmail.com>
Cc: Patrick McHardy <kaber@trash.net>
Cc: Jarek Poplawski <jarkao2@gmail.com>
Acked-by: Changli Gao <xiaosuo@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In dev_queue_xmit_nit(), we have to clone skbs as we need to mangle skbs,
however, we don't need to clone skbs for all the packet_types.
Except for the first packet_type, we increase skb->users instead of
skb_clone().
Signed-off-by: Changli Gao <xiaosuo@gmail.com>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Replace skb->csum_start - skb_headroom(skb) with skb_checksum_start_offset().
Note for usb/smsc95xx: skb->data - skb->head == skb_headroom(skb).
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add dev_close_many and dev_deactivate_many to factorize another
sync-rcu operation on the netdevice unregister path.
$ modprobe dummy numdummies=10000
$ ip link set dev dummy* up
$ time rmmod dummy
Without the patch With the patch
real 0m 24.63s real 0m 5.15s
user 0m 0.00s user 0m 0.00s
sys 0m 6.05s sys 0m 5.14s
Signed-off-by: Octavian Purdila <opurdila@ixiacom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Move the calcualation of the Tx hash for a given hash range into a separate
function and define the skb_tx_hash(), which calculates a Tx hash for a
[0; dev->real_num_tx_queues - 1] hash values range, using this
function (__skb_tx_hash()).
Signed-off-by: Vladislav Zolotarov <vladz@broadcom.com>
Signed-off-by: Eilon Greenstein <eilong@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Avoid some atomic ops on dst refcount, calling dev_queue_xmit_nit()
after skb_dst_drop() in dev_hard_start_xmit().
When queueing a packet into af_packet socket, we drop dst anyway.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Le dimanche 05 décembre 2010 à 09:19 +0100, Eric Dumazet a écrit :
> Hmm..
>
> If somebody can explain why RTNL is held in arp_ioctl() (and therefore
> in arp_req_delete()), we might first remove RTNL use in arp_ioctl() so
> that your patch can be applied.
>
> Right now it is not good, because RTNL wont be necessarly held when you
> are going to call arp_invalidate() ?
While doing this analysis, I found a refcount bug in llc, I'll send a
patch for net-2.6
Meanwhile, here is the patch for net-next-2.6
Your patch then can be applied after mine.
Thanks
[PATCH] net: RCU conversion of dev_getbyhwaddr() and arp_ioctl()
dev_getbyhwaddr() was called under RTNL.
Rename it to dev_getbyhwaddr_rcu() and change all its caller to now use
RCU locking instead of RTNL.
Change arp_ioctl() to use RCU instead of RTNL locking.
Note: this fix a dev refcount bug in llc
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The dev field of ingress queue is forgot to initialized, then NULL
pointer dereference happens in qdisc_alloc().
Move inits of tx queues to netif_alloc_netdev_queues().
Signed-off-by: Changli Gao <xiaosuo@gmail.com>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
NETIF_F_HW_CSUM is a superset of NETIF_F_IP_CSUM+NETIF_F_IPV6_CSUM, but
some drivers miss the difference. Fix this and also fix UFO dependency
on checksumming offload as it makes the same mistake in assumptions.
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Acked-by: Jon Mason <jon.mason@exar.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Allocate qdisc memory according to NUMA properties of cpus included in
xps map.
To be effective, qdisc should be (re)setup after changes
of /sys/class/net/eth<n>/queues/tx-<n>/xps_cpus
I added a numa_node field in struct netdev_queue, containing NUMA node
if all cpus included in xps_cpus share same node, else -1.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Ben Hutchings <bhutchings@solarflare.com>
Cc: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch adds XPS_CONFIG option to enable and disable XPS. This is
done in the same manner as RPS_CONFIG. This is also fixes build
failure in XPS code when SMP is not enabled.
Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch implements transmit packet steering (XPS) for multiqueue
devices. XPS selects a transmit queue during packet transmission based
on configuration. This is done by mapping the CPU transmitting the
packet to a queue. This is the transmit side analogue to RPS-- where
RPS is selecting a CPU based on receive queue, XPS selects a queue
based on the CPU (previously there was an XPS patch from Eric
Dumazet, but that might more appropriately be called transmit completion
steering).
Each transmit queue can be associated with a number of CPUs which will
use the queue to send packets. This is configured as a CPU mask on a
per queue basis in:
/sys/class/net/eth<n>/queues/tx-<n>/xps_cpus
The mappings are stored per device in an inverted data structure that
maps CPUs to queues. In the netdevice structure this is an array of
num_possible_cpu structures where each structure holds and array of
queue_indexes for queues which that CPU can use.
The benefits of XPS are improved locality in the per queue data
structures. Also, transmit completions are more likely to be done
nearer to the sending thread, so this should promote locality back
to the socket on free (e.g. UDP). The benefits of XPS are dependent on
cache hierarchy, application load, and other factors. XPS would
nominally be configured so that a queue would only be shared by CPUs
which are sharing a cache, the degenerative configuration woud be that
each CPU has it's own queue.
Below are some benchmark results which show the potential benfit of
this patch. The netperf test has 500 instances of netperf TCP_RR test
with 1 byte req. and resp.
bnx2x on 16 core AMD
XPS (16 queues, 1 TX queue per CPU) 1234K at 100% CPU
No XPS (16 queues) 996K at 100% CPU
Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In dev_pick_tx, don't do work in calculating queue
index or setting
the index in the sock unless the device has more than one queue. This
allows the sock to be set only with a queue index of a multi-queue
device which is desirable if device are stacked like in a tunnel.
We also allow the mapping of a socket to queue to be changed. To
maintain in order packet transmission a flag (ooo_okay) has been
added to the sk_buff structure. If a transport layer sets this flag
on a packet, the transmit queue can be changed for the socket.
Presumably, the transport would set this if there was no possbility
of creating OOO packets (for instance, there are no packets in flight
for the socket). This patch includes the modification in TCP output
for setting this flag.
Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
ERROR: "netif_get_vlan_features" [drivers/net/xen-netfront.ko] undefined!
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch move RX queue allocation to alloc_netdev_mq and freeing of
the queues to free_netdev (symmetric to TX queue allocation). Each
kobject RX queue takes a reference to the queue's device so that the
device can't be freed before all the kobjects have been released-- this
obviates the need for reference counts specific to RX queues.
Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
TX queues are now allocated in alloc_netdev_mq and freed in
free_netdev.
Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
We currently use vlan_features to check for TSO support if there is
a vlan tag. However, it's quite likely that the NIC is not able to
do TSO when there is an arbitrary number of tags. Therefore if there
is more than one tag (in-band or out-of-band), fall back to software
emulation.
Signed-off-by: Jesse Gross <jesse@nicira.com>
CC: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
We assume that hardware TSO can't support multiple levels of vlan tags
but we allow it to be done. Therefore, enable GSO to parse these tags
so we can fallback to software.
Signed-off-by: Jesse Gross <jesse@nicira.com>
CC: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When checking if it is necessary to linearize a packet, we currently
use vlan_features if the packet contains either an in-band or out-
of-band vlan tag. However, in-band tags aren't special in any way
for scatter/gather since they are part of the packet buffer and are
simply more data to DMA. Therefore, only use vlan_features for out-
of-band tags, which could potentially have some interaction with
scatter/gather.
Signed-off-by: Jesse Gross <jesse@nicira.com>
CC: Ben Hutchings <bhutchings@solarflare.com>
Reviewed-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In dev_pick_tx recompute the queue index if the value stored in the
socket is greater than or equal to the number of real queues for the
device. The saved index in the sock structure is not guaranteed to
be appropriate for the egress device (this could happen on a route
change or in presence of tunnelling). The result of the queue index
being bad would be to return a bogus queue (crash could prersumably
follow).
Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
NETIF_F_HW_CSUM indicates the ability to update an TCP/IP-style 16-bit
checksum with the checksum of an arbitrary part of the packet data,
whereas the FCoE CRC is something entirely different.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Cc: stable@kernel.org [2.6.32+]
Signed-off-by: David S. Miller <davem@davemloft.net>
dev_can_checksum() incorrectly returns true in these cases:
1. The skb has both out-of-band and in-band VLAN tags and the device
supports checksum offload for the encapsulated protocol but only with
one layer of encapsulation.
2. The skb has a VLAN tag and the device supports generic checksumming
but not in conjunction with VLAN encapsulation.
Rearrange the VLAN tag checks to avoid these.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add __rcu annotations to :
(struct netdev_rx_queue)->rps_map
(struct netdev_rx_queue)->rps_flow_table
struct rps_sock_flow_table *rps_sock_flow_table;
And use appropriate rcu primitives.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
