In the case where a non-MPLS packet is received and an MPLS stack is
added it may well be the case that the original skb is GSO but the
NIC used for transmit does not support GSO of MPLS packets.
The aim of this code is to provide GSO in software for MPLS packets
whose skbs are GSO.
SKB Usage:
When an implementation adds an MPLS stack to a non-MPLS packet it should do
the following to skb metadata:
* Set skb->inner_protocol to the old non-MPLS ethertype of the packet.
skb->inner_protocol is added by this patch.
* Set skb->protocol to the new MPLS ethertype of the packet.
* Set skb->network_header to correspond to the
end of the L3 header, including the MPLS label stack.
I have posted a patch, "[PATCH v3.29] datapath: Add basic MPLS support to
kernel" which adds MPLS support to the kernel datapath of Open vSwtich.
That patch sets the above requirements in datapath/actions.c:push_mpls()
and was used to exercise this code. The datapath patch is against the Open
vSwtich tree but it is intended that it be added to the Open vSwtich code
present in the mainline Linux kernel at some point.
Features:
I believe that the approach that I have taken is at least partially
consistent with the handling of other protocols. Jesse, I understand that
you have some ideas here. I am more than happy to change my implementation.
This patch adds dev->mpls_features which may be used by devices
to advertise features supported for MPLS packets.
A new NETIF_F_MPLS_GSO feature is added for devices which support
hardware MPLS GSO offload. Currently no devices support this
and MPLS GSO always falls back to software.
Alternate Implementation:
One possible alternate implementation is to teach netif_skb_features()
and skb_network_protocol() about MPLS, in a similar way to their
understanding of VLANs. I believe this would avoid the need
for net/mpls/mpls_gso.c and in particular the calls to
__skb_push() and __skb_push() in mpls_gso_segment().
I have decided on the implementation in this patch as it should
not introduce any overhead in the case where mpls_gso is not compiled
into the kernel or inserted as a module.
MPLS GSO suggested by Jesse Gross.
Based in part on "v4 GRE: Add TCP segmentation offload for GRE"
by Pravin B Shelar.
Cc: Jesse Gross <jesse@nicira.com>
Cc: Pravin B Shelar <pshelar@nicira.com>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Rename the hardware VLAN acceleration features to include "CTAG" to indicate
that they only support CTAGs. Follow up patches will introduce 802.1ad
server provider tagging (STAGs) and require the distinction for hardware not
supporting acclerating both.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Adds generic tunneling offloading support for IPv4-UDP based
tunnels.
GSO type is added to request this offload for a skb.
netdev feature NETIF_F_UDP_TUNNEL is added for hardware offloaded
udp-tunnel support. Currently no device supports this feature,
software offload is used.
This can be used by tunneling protocols like VXLAN.
CC: Jesse Gross <jesse@nicira.com>
Signed-off-by: Pravin B Shelar <pshelar@nicira.com>
Acked-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Following patch adds GRE protocol offload handler so that
skb_gso_segment() can segment GRE packets.
SKB GSO CB is added to keep track of total header length so that
skb_segment can push entire header. e.g. in case of GRE, skb_segment
need to push inner and outer headers to every segment.
New NETIF_F_GRE_GSO feature is added for devices which support HW
GRE TSO offload. Currently none of devices support it therefore GRE GSO
always fall backs to software GSO.
[ Compute pkt_len before ip_local_out() invocation. -DaveM ]
Signed-off-by: Pravin B Shelar <pshelar@nicira.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
No need to check if ethtool_ops == NULL since it can't be.
Use local variable "ops" in functions where it is present
instead of dev->ethtool_ops
Introduce local variable "ops" in functions where dev->ethtool_ops is used
many times.
Signed-off-by: Jiri Pirko <jiri@resnulli.us>
Reviewed-by: Ben Hutchings <bhutchings@solarflare.com>
Reviewed-by: Flavio Leitner <fbl@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Allow an unpriviled user who has created a user namespace, and then
created a network namespace to effectively use the new network
namespace, by reducing capable(CAP_NET_ADMIN) and
capable(CAP_NET_RAW) calls to be ns_capable(net->user_ns,
CAP_NET_ADMIN), or capable(net->user_ns, CAP_NET_RAW) calls.
Settings that merely control a single network device are allowed.
Either the network device is a logical network device where
restrictions make no difference or the network device is hardware NIC
that has been explicity moved from the initial network namespace.
In general policy and network stack state changes are allowed
while resource control is left unchanged.
Allow ethtool ioctls.
Allow binding to network devices.
Allow setting the socket mark.
Allow setting the socket priority.
Allow setting the network device alias via sysfs.
Allow setting the mtu via sysfs.
Allow changing the network device flags via sysfs.
Allow setting the network device group via sysfs.
Allow the following network device ioctls.
SIOCGMIIPHY
SIOCGMIIREG
SIOCSIFNAME
SIOCSIFFLAGS
SIOCSIFMETRIC
SIOCSIFMTU
SIOCSIFHWADDR
SIOCSIFSLAVE
SIOCADDMULTI
SIOCDELMULTI
SIOCSIFHWBROADCAST
SIOCSMIIREG
SIOCBONDENSLAVE
SIOCBONDRELEASE
SIOCBONDSETHWADDR
SIOCBONDCHANGEACTIVE
SIOCBRADDIF
SIOCBRDELIF
SIOCSHWTSTAMP
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Instead of forcing device drivers to provide empty ethtool_ops or tweak
net/core/ethtool.c again, we could provide a generic ethtool_ops.
This occurred to me when I wanted to add GSO support to GRE tunnels.
ethtool -k support should be generic for all drivers.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Ben Hutchings <bhutchings@solarflare.com>
Cc: Maciej Żenczykowski <maze@google.com>
Reviewed-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
'Get' commands should generally not require CAP_NET_ADMIN, with
the exception of those that expose internal state.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch extends the kernel's ethtool interface by adding support
for 2 new EEE commands - get_eee and set_eee.
Thanks goes to Giuseppe Cavallaro for his original patch adding this support.
Signed-off-by: Yuval Mintz <yuvalmin@broadcom.com>
Signed-off-by: Eilon Greenstein <eilong@broadcom.com>
Reviewed-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
ETHTOOL_GMODULEINFO returns a new struct ethtool_modinfo that will return the
type and size of plug-in module eeprom (such as SFP+) for parsing
by userland program.
ETHTOOL_GMODULEEEPROM returns the raw eeprom information
using the existing ethtool_eeprom structture to return the data
Signed-off-by: Stuart Hodgson <smhodgson@solarflare.com>
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
We want to support reading module (SFP+, XFP, ...) EEPROMs as well as
NIC EEPROMs. They will need a different command number and driver
operation, but the structure and arguments will be the same and so we
can share most of the code here.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Currently, most drivers do not support transmit SO_TIMESTAMPING. For those
that do support it, there is one appropriate response to the get_ts_info
query. This patch adds a common function providing this response.
Signed-off-by: Richard Cochran <richardcochran@gmail.com>
Reviewed-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit adds a new ethtool ioctl that exposes the SO_TIMESTAMPING
capabilities of a network interface. In addition, user space programs
can use this ioctl to discover the PTP Hardware Clock (PHC) device
associated with the interface.
Since software receive time stamps are handled by the stack, the generic
ethtool code can answer the query correctly in case the MAC or PHY
drivers lack special time stamping features.
Signed-off-by: Richard Cochran <richardcochran@gmail.com>
Reviewed-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This flag requests that network devices pass all
received frames up the stack, even ones with errors
such as invalid FCS (frame check sum). This will
allow sniffers to see bad packets and perhaps
give the user some idea how to fix the problem.
Signed-off-by: Ben Greear <greearb@candelatech.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
When set on hardware that supports the feature,
this causes the Ethernet FCS to be appended
to the end of the skb.
Useful for sniffing packets.
Signed-off-by: Ben Greear <greearb@candelatech.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
The parameters for ETHTOOL_FLASHDEV include a filename, which ought to
be null-terminated. Currently the only driver that implements
ethtool_ops::flash_device attempts to add a null terminator if
necessary, but does it wrongly. Do it in the ethtool core instead.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Allow ETHTOOL_GSSET_INFO ethtool ioctl() for unprivileged users.
ETHTOOL_GSTRINGS is already allowed, but is unusable without this one.
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Acked-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
All implementations have been converted to implement set_rxnfc
instead.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Define special location values for RX NFC that request the driver to
select the actual rule location. This allows for implementation on
devices that use hash-based filter lookup, whereas currently the API is
more suited to devices with TCAM lookup or linear search.
In ethtool_set_rxnfc() and the compat wrapper ethtool_ioctl(), copy
the structure back to user-space after insertion so that the actual
location is returned.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
All drivers that support modification of the RX flow hash indirection
table initialise it in the same way: RX rings are assigned to table
entries in rotation. Make that default policy explicit by having them
call a ethtool_rxfh_indir_default() function.
In the ethtool core, add support for a zero size value for
ETHTOOL_SRXFHINDIR, which resets the table to this default.
Partly-suggested-by: Matt Carlson <mcarlson@broadcom.com>
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Acked-by: Shreyas N Bhatewara <sbhatewara@vmware.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add a new ethtool operation (get_rxfh_indir_size) to get the
indirectional table size. Use this to validate the user buffer size
before calling get_rxfh_indir or set_rxfh_indir. Use get_rxnfc to get
the number of RX rings, and validate the contents of the new
indirection table before calling set_rxfh_indir. Remove this
validation from drivers.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Acked-by: Dimitris Michailidis <dm@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add missing spaces around multiplication operator.
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: David S. Miller <davem@davemloft.net>
Only distinct use is checking if NETIF_F_NOCACHE_COPY should be
enabled by default. The check heuristics is altered a bit here,
so it hits other people than before. The default shouldn't be
trusted for performance-critical cases anyway.
For all other uses NETIF_F_NO_CSUM is equivalent to NETIF_F_HW_CSUM.
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: David S. Miller <davem@davemloft.net>
v2: changed loop in ethtool_set_features() per Ben's suggestion
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: David S. Miller <davem@davemloft.net>
v2: add couple missing conversions in drivers
split unexporting netdev_fix_features()
implemented %pNF
convert sock::sk_route_(no?)caps
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: David S. Miller <davem@davemloft.net>
This is the only place left where dev->features are directly
exposed to userspace.
I know checkpatch.pl complains about __ethtool_{get,set}_flags(), but
the code is easier to read this way.
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Acked-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
As all drivers are converted, we may now remove discrete offload setting
callback handling.
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Acked-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch does several things:
- introduces __ethtool_get_settings which is called from ethtool code and
from drivers as well. Put ASSERT_RTNL there.
- dev_ethtool_get_settings() is replaced by __ethtool_get_settings()
- changes calling in drivers so rtnl locking is respected. In
iboe_get_rate was previously ->get_settings() called unlocked. This
fixes it. Also prb_calc_retire_blk_tmo() in af_packet.c had the same
problem. Also fixed by calling __dev_get_by_index() instead of
dev_get_by_index() and holding rtnl_lock for both calls.
- introduces rtnl_lock in bnx2fc_vport_create() and fcoe_vport_create()
so bnx2fc_if_create() and fcoe_if_create() are called locked as they
are from other places.
- use __ethtool_get_settings() in bonding code
Signed-off-by: Jiri Pirko <jpirko@redhat.com>
v2->v3:
-removed dev_ethtool_get_settings()
-added ASSERT_RTNL into __ethtool_get_settings()
-prb_calc_retire_blk_tmo - use __dev_get_by_index() and lock
around it and __ethtool_get_settings() call
v1->v2:
add missing export_symbol
Reviewed-by: Ben Hutchings <bhutchings@solarflare.com> [except FCoE bits]
Acked-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Some drivers (ab)use the ethtool_ops::get_regs operation to expose
only a hardware revision ID. Commit
a77f5db361 ('ethtool: Allocate register
dump buffer with vmalloc()') had the side-effect of breaking these, as
vmalloc() returns a null pointer for size=0 whereas kmalloc() did not.
For backward-compatibility, allow zero-length dumps again.
Reported-by: Kalle Valo <kvalo@qca.qualcomm.com>
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Cc: stable@kernel.org [2.6.37+]
Signed-off-by: David S. Miller <davem@davemloft.net>
This change is meant to remove all support for displaying an ntuple as
strings via ETHTOOL_GRXNTUPLE. The reason for this change is due to the
fact that multiple issues have been found including:
- Multiple buffer overruns for strings being displayed.
- Incorrect filters displayed, cleared filters with ring of -2 are displayed
- Setting get_rx_ntuple displays no rules if defined.
- Endianess wrong on displayed values.
- Hard limit of 1024 filters makes display functionality extremely limited
The only driver that had supported this interface was ixgbe. Since it no
longer uses the interface and due to the issues mentioned above I am
submitting this patch to remove it.
v2:
Updated based on comments from Ben Hutchings
- Left ETH_SS_NTUPLE_FILTERS in code but commented on it being deprecated
- Removed ethtool_rx_ntuple_list and ethtool_rx_ntuple_flow_spec_container
- Left ETHTOOL_GRXNTUPLE but commented it as deprecated
Also cleaned up set_rx_ntuple since there is no flow spec container to
maintain we can drop all the code for the alloc and free of it and just
return ops->set_rx_ntuple().
Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Acked-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Current code squashes flags to bool - this makes set_flags fail whenever
some ETH_FLAG_* equivalent features are set. Fix this.
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: David S. Miller <davem@davemloft.net>
Added code to take FW dump via ethtool. Dump level can be controlled via setting the
dump flag. A get function is provided to query the current setting of the dump flag.
Dump data is obtained from the driver via a separate get function.
Changes from v3:
Fixed buffer length issue in ethtool_get_dump_data function.
Updated kernel doc for ethtool_dump struct and get_dump_flag function.
Changes from v2:
Provided separate commands for get flag and data.
Check for minimum of the two buffer length obtained via ethtool and driver and
use that for dump buffer
Pass up the driver return error codes up to the caller.
Added kernel doc comments.
Signed-off-by: Anirban Chakraborty <anirban.chakraborty@qlogic.com>
Reviewed-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The issue was introduced in commit eed2a12f1e.
Signed-off-by: Franco Fichtner <franco@lastsummer.de>
Acked-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Acked-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch enables ethtool to set the loopback mode on a given interface.
By configuring the interface in loopback mode in conjunction with a policy
route / rule, a userland application can stress the egress / ingress path
exposing the flows of the change in progress and potentially help developer(s)
understand the impact of those changes without even sending a packet out
on the network.
Following set of commands illustrates one such example -
a) ip -4 addr add 192.168.1.1/24 dev eth1
b) ip -4 rule add from all iif eth1 lookup 250
c) ip -4 route add local 0/0 dev lo proto kernel scope host table 250
d) arp -Ds 192.168.1.100 eth1
e) arp -Ds 192.168.1.200 eth1
f) sysctl -w net.ipv4.ip_nonlocal_bind=1
g) sysctl -w net.ipv4.conf.all.accept_local=1
# Assuming that the machine has 8 cores
h) taskset 000f netserver -L 192.168.1.200
i) taskset 00f0 netperf -t TCP_CRR -L 192.168.1.100 -H 192.168.1.200 -l 30
Signed-off-by: Mahesh Bandewar <maheshb@google.com>
Acked-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
After that all the upstream kernel drivers now use phys_id,
and the old ethtool_ops interface (phys_id) can be removed.
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
__ethtool_set_flags() was not taking into account features set but not
user-toggleable.
Since GFLAGS returns masked dev->features, EINVAL is returned when
passed flags differ to it, and not to wanted_features.
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: David S. Miller <davem@davemloft.net>
When physical identification of an adapter is done by toggling the
mechanism on and off through software utilizing the set_phys_id operation,
it is done with a fixed duration for both on and off states. Some drivers
may want to set a custom duration for the on/off intervals. This patch
changes the API so the return code from the driver's entry point when it
is called with ETHTOOL_ID_ACTIVE can specify the frequency at which to
cycle the on/off states, and updates the drivers that have already been
converted to use the new set_phys_id and use the synchronous method for
identifying an adapter.
The physical identification frequency set in the updated drivers is based
on how it was done prior to the introduction of set_phys_id.
Compile tested only. Also fixes a compiler warning in sfc.
v2: drivers do not return -EINVAL for ETHOOL_ID_ACTIVE
v3: fold patchset into single patch and cleanup per Ben's feedback
Signed-off-by: Bruce Allan <bruce.w.allan@intel.com>
Cc: Ben Hutchings <bhutchings@solarflare.com>
Cc: Sathya Perla <sathya.perla@emulex.com>
Cc: Subbu Seetharaman <subbu.seetharaman@emulex.com>
Cc: Ajit Khaparde <ajit.khaparde@emulex.com>
Cc: Michael Chan <mchan@broadcom.com>
Cc: Eilon Greenstein <eilong@broadcom.com>
Cc: Divy Le Ray <divy@chelsio.com>
Cc: Don Fry <pcnet32@frontier.com>
Cc: Jon Mason <jdmason@kudzu.us>
Cc: Solarflare linux maintainers <linux-net-drivers@solarflare.com>
Cc: Steve Hodgson <shodgson@solarflare.com>
Cc: Stephen Hemminger <shemminger@linux-foundation.org>
Cc: Matt Carlson <mcarlson@broadcom.com>
Acked-by: Jon Mason <jdmason@kudzu.us>
Acked-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Ethtool support to configure RX, TX and other channels. combined field
in struct ethtool_channels to reflect set of channel (RX, TX or other).
Other channel can be link interrupts, SR-IOV coordination etc.
ETHTOOL_GCHANNELS will report max and current number of RX channels,
max and current number of TX channels, max and current number of other channel
or max and current number of combined channel.
Number of channel can be modify upto max number of channel through
ETHTOOL_SCHANNELS command.
Ben Hutchings:
o define 'combined' and 'other' types. Most multiqueue drivers pair up RX and TX
queues so that most channels combine RX and TX work.
o Please could you use a kernel-doc comment to describe the structure.
Signed-off-by: Amit Kumar Salecha <amit.salecha@qlogic.com>
Reviewed-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When blinking for a duration set by the user, the value specified is in
seconds but it is used as the number of jiffies in the timeout after which
the Physical ID indicator is deactivated. Fix by converting the timeout
to seconds.
Signed-off-by: Bruce Allan <bruce.w.allan@intel.com>
Acked-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This change is meant to prevent a possible null pointer dereference if
NETIF_F_NTUPLE is defined but the set_rx_ntuple function pointer is not.
The main motivation behind this patch is to eventually replace the ntuple
interfaces entirely with the network flow classifier interfaces. This
allows the device drivers to maintain the ntuple check internally while
using the network flow classifier interface for setting up and displaying
rules.
Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The ethtool ETHTOOL_PHYS_ID command runs for an arbitrarily long
period of time, holding the RTNL lock. This blocks routing updates,
device enumeration, and various important operations that one might
want to keep running while hunting for the flashing LED.
We need to drop the RTNL lock during this operation, but currently the
core implementation is a thin wrapper around a driver operation and
drivers may well depend upon holding the lock.
Define a new driver operation 'set_phys_id' with an argument that sets
the ID indicator on/off/inactive/active (the last optional, for any
driver or firmware that prefers to handle blinking asynchronously).
When this is defined, the ethtool core drops the lock while waiting
and only acquires it around calls to this operation.
Deprecate the 'phys_id' operation in favour of this. It can be
removed once all in-tree drivers are converted.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
This patch uses __copy_from_user_nocache on transmit to bypass data
cache for a performance improvement. skb_add_data_nocache and
skb_copy_to_page_nocache can be called by sendmsg functions to use
this feature, initial support is in tcp_sendmsg. This functionality is
configurable per device using ethtool.
Presumably, this feature would only be useful when the driver does
not touch the data. The feature is turned on by default if a device
indicates that it does some form of checksum offload; it is off by
default for devices that do no checksum offload or indicate no checksum
is necessary. For the former case copy-checksum is probably done
anyway, in the latter case the device is likely loopback in which case
the no cache copy is probably not beneficial.
This patch was tested using 200 instances of netperf TCP_RR with
1400 byte request and one byte reply. Platform is 16 core AMD x86.
No-cache copy disabled:
672703 tps, 97.13% utilization
50/90/99% latency:244.31 484.205 1028.41
No-cache copy enabled:
702113 tps, 96.16% utilization,
50/90/99% latency 238.56 467.56 956.955
Using 14000 byte request and response sizes demonstrate the
effects more dramatically:
No-cache copy disabled:
79571 tps, 34.34 %utlization
50/90/95% latency 1584.46 2319.59 5001.76
No-cache copy enabled:
83856 tps, 34.81% utilization
50/90/95% latency 2508.42 2622.62 2735.88
Note especially the effect on latency tail (95th percentile).
This seems to provide a nice performance improvement and is
consistent in the tests I ran. Presumably, this would provide
the greatest benfits in the presence of an application workload
stressing the cache and a lot of transmit data happening.
Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Issue FEAT_CHANGE notification when features are changed by
netdev_update_features(). This will allow changes made by extra constraints
on e.g. MTU change to be properly propagated like changes via ethtool.
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: David S. Miller <davem@davemloft.net>
