These functions compile to 60 bytes of machine code each.
With this .config: http://busybox.net/~vda/kernel_config
there are 617 calls of netif_tx_stop_queue()
and 49 calls of netif_tx_stop_all_queues() in vmlinux.

To fix this, remove WARN_ON in netif_tx_stop_queue()
as suggested by davem, and deinline netif_tx_stop_all_queues().

Change in code size is about 20k:

   text      data      bss       dec     hex filename
82426986 22255416 20627456 125309858 77813a2 vmlinux.before
82406248 22255416 20627456 125289120 777c2a0 vmlinux

gcc-4.7.2 still creates deinlined version of netif_tx_stop_queue
sometimes:

$ nm --size-sort vmlinux | grep netif_tx_stop_queue | wc -l
190

ffffffff81b558a8 <netif_tx_stop_queue>:
ffffffff81b558a8:       55                      push   %rbp
ffffffff81b558a9:       48 89 e5                mov    %rsp,%rbp
ffffffff81b558ac:       f0 80 8f e0 01 00 00    lock orb $0x1,0x1e0(%rdi)
ffffffff81b558b3:       01
ffffffff81b558b4:       5d                      pop    %rbp
ffffffff81b558b5:       c3                      retq

This needs additional fixing.
Signed-off-by: NDenys Vlasenko <dvlasenk@redhat.com>
CC: Alexei Starovoitov <alexei.starovoitov@gmail.com>
CC: Alexander Duyck <alexander.duyck@gmail.com>
CC: Joe Perches <joe@perches.com>
CC: David S. Miller <davem@davemloft.net>
CC: Jiri Pirko <jpirko@redhat.com>
CC: linux-kernel@vger.kernel.org
CC: netdev@vger.kernel.org
CC: netfilter-devel@vger.kernel.org
Acked-by: NAlexei Starovoitov <ast@plumgrid.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The macvtap driver tries to emulate all the ioctls supported by a normal
tun/tap driver, however it was missing the generic SIOCGIFHWADDR and
SIOCSIFHWADDR ioctls to get and set the mac address that are supported
by tun/tap. This patch adds these.
Signed-off-by: NJustin Cormack <justin@netbsd.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Scott Feldman says:

====================
switchdev: spring cleanup

v7:

Address review comments:

 - [Jiri] split the br_setlink and br_dellink reverts into their own patches
 - [Jiri] some parameter cleanup of rocker's memory allocators
 - [Jiri] pass trans mode as formal parameter rather than hanging off of
     rocker_port.

v6:

Address review comments:

 - [Jiri] split a couple of patches into one-logical-change per patch
 - [Joe Perches] revert checkpatch -f changes for wrapped lines with long
     symbols.

v5:

Address review comments:

 - [Jiri] include Jiri's s/swdev/switchdev rename patches up front.
 - [Jiri] squash some patches.  Now setlink/dellink/getlink patches are in
     three parts: new implementation, convert drivers to new, delete old impl.
 - [Jiri] some minor variable renames
 - [Jiri] use BUG_ON rather than WARN when COMMIT phase fails when PREPARE
     phase said it was safe to come into the water.
 - [Simon] rocker: fix a few transaction prepare-commit cases that were wrong.
     This was the bulk of the changes in v5.

v4:

Well, it was a lot of work, but now prepare-commit transaction model is how
davem advises: if prepare fails, abort the transaction.  The driver must do
resource reservations up front in prepare phase and return those resources if
aborting.  Commit phase would use reserved resources.  The good news is the
driver code (for rocker) now handles resource allocation failures better by not
leaving partially device or driver states.  This is a side-effect of the
prepare phase where state isn't modified; only validation of inputs and
resource reservations happen in the prepare phase.  Since we're supporting
setting attrs and add objs across lower devs in the stacked case, we need to
hold rtnl_lock (or ensure rtnl_lock is held) so lower devs don't move on us
during the prepare-commit transaction.  DSA driver code skips the prepare phase
and goes straight for the commit phase since no up-front allocations are done
and no device failures (that could be detected in the prepare phase) can
happen.

Remove NETIF_F_HW_SWITCH_OFFLOAD from rocker and the swdev_attr_set/get
wrappers.  DSA doesn't set NETIF_F_HW_SWITCH_OFFLOAD, so it can't be in
swdev_attr_set/get.  rocker doesn't need it; or rather can't support
NETIF_F_HW_SWITCH_OFFLOAD being set/cleared at run-time after the device
port is already up and offloading L2/L3.  NETIF_F_HW_SWITCH_OFFLOAD is still
left as a feature flag for drivers that can use it.

Drop the renaming patch for netdev_switch_notifier.  Other renames are a
result of moving to the attr get/set or obj add/del model.  Everything
but the netdev_switch_notifier is still prefixed with "swdev_".

v3:

Move to two-phase prepare-commit transaction model for attr set and obj add.
Driver gets a change in prepare phase to NACK transaction if lack of resources
or support in device.

v2:

Address review comments:

 - [Jiri] squash a few related patches
 - [Roopa] don't remove NETIF_F_HW_SWITCH_OFFLOAD
 - [Roopa] address VLAN setlink/dellink
 - [Ronen] print warning is attr set revert fails

Not address:

 - Using something other than "swdev_" prefix
 - Vendor extentions

The patch set grew a bit to not only support port attr get/set but also add
support for port obj add/del.  Example of port objs are VLAN, FDB entries, and
FIB entries.  The VLAN support now allows the swdev driver to get VLAN ranges
and flags like PVID and "untagged".  Sridhar will be adding FDB obj support
in follow-on patch.

v1:

The main theme of this patch set is to cleanup swdev in preparation for
new features or fixes to be added soon.  We have a pretty good idea now how
to handle stacked drivers in swdev, but there where some loose ends.  For
example, if a set failed in the middle of walking the lower devs, we would
leave the system in an undefined state...there was no way to recover back to
the previous state.  Speaking of sets, also recognize a pattern that most
swdev API accesses are gets or sets of port attributes, so go ahead and make
port attr get/set the central swdev API, and convert everything that is
set-ish/get-ish to this new API.

Features/fixes that should follow from this cleanup:

 - solve the duplicate pkt forwarding issue
 - get/set bridge attrs, like ageing_time, from/to device
 - get/set more bridge port attrs from/to device

There are some rename cleanups tagging along at the end, to give swdev
consistent naming.

And finally, some much needed updates to the switchdev.txt documentation to
hopefully capture the state-of-the-art of swdev.  Hopefully, we can do a better
job keeping this document up-to-date.

Tested with rocker, of course, to make sure nothing functional broke.  There
are a couple minor tweaks to DSA code for getting switch ID and setting STP
updates to use new API, but not expecting amy breakage there.
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Much need updated of switchdev documentation to cover what's been
implmented to-date.  There are some XXX comments in the text for
unimplemented or broken items.  I'd like to keep these in there (poor-man's
TODO list) and update the document once each issue is resolved.
Signed-off-by: NScott Feldman <sfeldma@gmail.com>
Acked-by: NJiri Pirko <jiri@resnulli.us>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Well almost clean: ignore the CHECKs for space after cast operator and some
longer-than-80 char cases where for readability it's better to keep as-is.
Signed-off-by: NScott Feldman <sfeldma@gmail.com>
Acked-by: NJiri Pirko <jiri@resnulli.us>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Roopa said remove the feature flag for this series and she'll work on
bringing it back if needed at a later date.
Signed-off-by: NScott Feldman <sfeldma@gmail.com>
Acked-by: NJiri Pirko <jiri@resnulli.us>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The IPv4 FIB ops convert nicely to the switchdev objs and we're left with
only four switchdev ops: port get/set and port add/del.  Other objs will
follow, such as FDB.  So go ahead and convert IPv4 FIB over to switchdev
obj for consistency, anticipating more objs to come.
Signed-off-by: NScott Feldman <sfeldma@gmail.com>
Acked-by: NJiri Pirko <jiri@resnulli.us>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NScott Feldman <sfeldma@gmail.com>
Acked-by: NJiri Pirko <jiri@resnulli.us>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Like bridge_setlink, add switchdev wrapper to handle bridge_getlink and
call into port driver to get port attrs.  For now, only BR_LEARNING and
BR_LEARNING_SYNC are returned.  To add more, we'll probably want to break
away from ndo_dflt_bridge_getlink() and build the netlink skb directly in
the switchdev code.
Signed-off-by: NScott Feldman <sfeldma@gmail.com>
Acked-by: NJiri Pirko <jiri@resnulli.us>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This is revert of:

commit 68e331c7 ("bridge: offload bridge port attributes to switch asic
if feature flag set")

Restore br_dellink back to original and don't call into SELF port driver.
rtnetlink.c:bridge_dellink() already does a call into port driver for SELF.

bridge vlan add/del cmd defaults to MASTER.  From man page for bridge vlan
add/del cmd:

       self   the vlan is configured on the specified physical device.
              Required if the device is the bridge device.

       master the vlan is configured on the software bridge (default).
Signed-off-by: NScott Feldman <sfeldma@gmail.com>
Acked-by: NJiri Pirko <jiri@resnulli.us>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Now we can remove old wrappers for dellink.
Signed-off-by: NScott Feldman <sfeldma@gmail.com>
Acked-by: NJiri Pirko <jiri@resnulli.us>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Rocker, bonding and team and switch over to the new
switchdev_port_bridge_dellink to avoid duplicating code in each driver.
Signed-off-by: NScott Feldman <sfeldma@gmail.com>
Acked-by: NJiri Pirko <jiri@resnulli.us>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Same change as setlink.  Provide the wrapper op for SELF ndo_bridge_dellink
and call into the switchdev driver to delete afspec VLANs.
Signed-off-by: NScott Feldman <sfeldma@gmail.com>
Acked-by: NJiri Pirko <jiri@resnulli.us>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This is revert of:

commit 68e331c7 ("bridge: offload bridge port attributes to switch asic
if feature flag set")

Restore br_setlink back to original and don't call into SELF port driver.
rtnetlink.c:bridge_setlink() already does a call into port driver for SELF.

bridge set link cmd defaults to MASTER.  From man page for bridge link set
cmd:

       self   link setting is configured on specified physical device

       master link setting is configured on the software bridge (default)

The link setting has two values: the device-side value and the software
bridge-side value.  These are independent and settable using the bridge
link set cmd by specifying some combination of [master] | [self].
Furthermore, the device-side and bridge-side settings have their own
initial value, viewable from bridge -d link show cmd.

Restoring br_setlink back to original makes rocker (the only in-kernel user
of SELF link settings) work as first implement: two-sided values.

It's true that when both MASTER and SELF are specified from the command,
two netlink notifications are generated, one for each side of the settings.
The user-space app can distiquish between the two notifications by
observing the MASTER or SELF flag.
Signed-off-by: NScott Feldman <sfeldma@gmail.com>
Acked-by: NJiri Pirko <jiri@resnulli.us>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

New attr-based bridge_setlink can recurse lower devs and recover on err, so
remove old wrapper (including ndo_dflt_switchdev_port_bridge_setlink).
Signed-off-by: NScott Feldman <sfeldma@gmail.com>
Acked-by: NJiri Pirko <jiri@resnulli.us>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Rocker, bonding, and team can now use the switchdev bridge setlink to parse
raw netlink; no need to duplicate this code in each driver.
Signed-off-by: NScott Feldman <sfeldma@gmail.com>
Acked-by: NJiri Pirko <jiri@resnulli.us>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add new switchdev_port_bridge_setlink that can be used by drivers
implementing .ndo_bridge_setlink to set switchdev bridge attributes.
Basically turn the raw rtnl_bridge_setlink netlink into switchdev attr
sets.  Proper netlink attr policy checking is done on the protinfo part of
the netlink msg.

Currently, for protinfo, only bridge port attrs BR_LEARNING and
BR_LEARNING_SYNC are parsed and passed to port driver.

For afspec, VLAN objs are passed so switchdev driver can set VLANs assigned
to SELF.  To illustrate with iproute2 cmd, we have:

	bridge vlan add vid 10 dev sw1p1 self master

To add VLAN 10 to port sw1p1 for both the bridge (master) and the device
(self).
Signed-off-by: NScott Feldman <sfeldma@gmail.com>
Acked-by: NJiri Pirko <jiri@resnulli.us>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

rocker: use switchdev get/set attr for bridge port flags
Signed-off-by: NScott Feldman <sfeldma@gmail.com>
Acked-by: NJiri Pirko <jiri@resnulli.us>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NScott Feldman <sfeldma@gmail.com>
Acked-by: NJiri Pirko <jiri@resnulli.us>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

VLAN obj has flags (PVID and untagged) as well as start and end vid ranges.
The switchdev driver can optimize programing the device using the ranges.
Signed-off-by: NScott Feldman <sfeldma@gmail.com>
Acked-by: NJiri Pirko <jiri@resnulli.us>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Like switchdev attr get/set, add new switchdev obj add/del.  switchdev objs
will be things like VLANs or FIB entries, so add/del fits better for
objects than get/set used for attributes.

Use same two-phase prepare-commit transaction model as in attr set.
Signed-off-by: NScott Feldman <sfeldma@gmail.com>
Acked-by: NSridhar Samudrala <sridhar.samudrala@intel.com>
Acked-by: NJiri Pirko <jiri@resnulli.us>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

STP update is just a settable port attribute, so convert
switchdev_port_stp_update to an attr set.

For DSA, the prepare phase is skipped and STP updates are only done in the
commit phase.  This is because currently the DSA drivers don't need to
allocate any memory for STP updates and the STP update will not fail to HW
(unless something horrible goes wrong on the MDIO bus, in which case the
prepare phase wouldn't have been able to predict anyway).
Signed-off-by: NScott Feldman <sfeldma@gmail.com>
Acked-by: NJiri Pirko <jiri@resnulli.us>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

For rocker, support prepare-commit transaction model for setting attributes
(and for adding objects).  This requires rocker to preallocate memory
needed for the commit up front in the prepare phase.  Since rtnl_lock is
held between prepare-commit, store the allocated memory on a queue hanging
off of the rocker_port.  Also, in prepare phase, do everything right up to
calling into HW.  The same code paths are tranversed in the driver for both
prepare and commit phases.  In some cases, any state modified in the
prepare phase must be reverted before returning so the commit phase makes
the same decisions.

As a consequence of holding rtnl_lock in process context for all attr sets
(and obj adds), all memory is GFP_KERNEL allocated and we don't need to
busy spin waiting for the device to complete the command.  So the bulk of
this patch is simplifying the memory allocations to only use GFP_KERNEL and
to remove the nowait flag and busy spin loop.
Signed-off-by: NScott Feldman <sfeldma@gmail.com>
Acked-by: NJiri Pirko <jiri@resnulli.us>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Switch ID is just a gettable port attribute.  Convert switchdev op
switchdev_parent_id_get to a switchdev attr.

Note: for sysfs and netlink interfaces, SWITCHDEV_ATTR_PORT_PARENT_ID is
called with SWITCHDEV_F_NO_RECUSE to limit switch ID user-visiblity to only
port netdevs.  So when a port is stacked under bond/bridge, the user can
only query switch id via the switch ports, but not via the upper devices
Signed-off-by: NScott Feldman <sfeldma@gmail.com>
Acked-by: NJiri Pirko <jiri@resnulli.us>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add two new swdev ops for get/set switch port attributes.  Most swdev
interactions on a port are gets or sets on port attributes, so rather than
adding ops for each attribute, let's define clean get/set ops for all
attributes, and then we can have clear, consistent rules on how attributes
propagate on stacked devs.

Add the basic algorithms for get/set attr ops.  Use the same recusive algo
to walk lower devs we've used for STP updates, for example.  For get,
compare attr value for each lower dev and only return success if attr
values match across all lower devs.  For sets, set the same attr value for
all lower devs.  We'll use a two-phase prepare-commit transaction model for
sets.  In the first phase, the driver(s) are asked if attr set is OK.  If
all OK, the commit attr set in second phase.  A driver would NACK the
prepare phase if it can't set the attr due to lack of resources or support,
within it's control.  RTNL lock must be held across both phases because
we'll recurse all lower devs first in prepare phase, and then recurse all
lower devs again in commit phase.  If any lower dev fails the prepare
phase, we need to abort the transaction for all lower devs.

If lower dev recusion isn't desired, allow a flag SWITCHDEV_F_NO_RECURSE to
indicate get/set only work on port (lowest) device.
Signed-off-by: NScott Feldman <sfeldma@gmail.com>
Acked-by: NJiri Pirko <jiri@resnulli.us>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Turned out that "switchdev" sticks. So just unify all related terms to use
this prefix.
Signed-off-by: NJiri Pirko <jiri@resnulli.us>
Signed-off-by: NScott Feldman <sfeldma@gmail.com>
Acked-by: NRoopa Prabhu <roopa@cumulusnetworks.com>
Acked-by: NAndy Gospodarek <gospo@cumulusnetworks.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Turned out that "switchdev" sticks. So just unify all related terms to use
this prefix.
Signed-off-by: NJiri Pirko <jiri@resnulli.us>
Signed-off-by: NScott Feldman <sfeldma@gmail.com>
Acked-by: NRoopa Prabhu <roopa@cumulusnetworks.com>
Acked-by: NAndy Gospodarek <gospo@cumulusnetworks.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In a GRED qdisc, if the default "virtual queue" (VQ) does not have drop
parameters configured, then packets for the default VQ are not subjected
to RED and are only dropped if the queue is larger than the net_device's
tx_queue_len. This behavior is useful for WRED mode, since these packets
will still influence the calculated average queue length and (therefore)
the drop probability for all of the other VQs. However, for some drivers
tx_queue_len is zero. In other cases the user may wish to make the limit
the same for all VQs (including the default VQ with no drop parameters).

This change adds a TCA_GRED_LIMIT attribute to set the GRED queue limit,
in bytes, during qdisc setup. (This limit is in bytes to be consistent
with the drop parameters.) The default limit is the same as for a bfifo
queue (tx_queue_len * psched_mtu). If the drop parameters of any VQ are
configured with a smaller limit than the GRED queue limit, that VQ will
still observe the smaller limit instead.
Signed-off-by: NDavid Ward <david.ward@ll.mit.edu>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NNicolas Schichan <nschichan@freebox.fr>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Alexander Duyck says:

====================
Refactor netdev page frags and move them into mm/

This patch series addresses several things.

First I found an issue in the performance of the pfmemalloc check from
build_skb.  To work around it I have provided a cached copy of pfmemalloc
to be used in __netdev_alloc_skb and __napi_alloc_skb.

Second I moved the page fragment allocation logic into the mm tree and
added functionality for freeing page fragments.  I had to fix igb before I
could do this as it was using a reference to NETDEV_FRAG_PAGE_MAX_SIZE
incorrectly.

Finally I went through and replaced all of the duplicate code that was
calling put_page and replaced it with calls to skb_free_frag.

With these changes in place a simple receive and drop test increased from a
packet rate of 8.9Mpps to 9.8Mpps.  The gains breakdown as follows:

8.9Mpps	Before			9.8Mpps	After
------------------------	------------------------
7.8%	put_compound_page	9.1%	__free_page_frag
3.9%	skb_free_head
1.1%	put_page

4.9%	build_skb		3.8%	__napi_alloc_skb
2.5%	__alloc_rx_skb
1.9%	__napi_alloc_skb
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NAlexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NAlexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NAlexander Duyck <alexander.h.duyck@redhat.com>
Acked-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NAlexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NAlexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This change adds a function called skb_free_frag which is meant to
compliment the function netdev_alloc_frag.  The general idea is to enable a
more lightweight version of page freeing since we don't actually need all
the overhead of a put_page, and we don't quite fit the model of __free_pages.
Signed-off-by: NAlexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This change moves the __alloc_page_frag functionality out of the networking
stack and into the page allocation portion of mm.  The idea it so help make
this maintainable by placing it with other page allocation functions.

Since we are moving it from skbuff.c to page_alloc.c I have also renamed
the basic defines and structure from netdev_alloc_cache to page_frag_cache
to reflect that this is now part of a different kernel subsystem.

I have also added a simple __free_page_frag function which can handle
freeing the frags based on the skb->head pointer.  The model for this is
based off of __free_pages since we don't actually need to deal with all of
the cases that put_page handles.  I incorporated the virt_to_head_page call
and compound_order into the function as it actually allows for a signficant
size reduction by reducing code duplication.
Signed-off-by: NAlexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This change makes it so that we store the virtual address of the page
in the netdev_alloc_cache instead of the page pointer.  The idea behind
this is to avoid multiple calls to page_address since the virtual address
is required for every access, but the page pointer is only needed at
allocation or reset of the page.

While I was at it I also reordered the netdev_alloc_cache structure a bit
so that the size is always 16 bytes by dropping size in the case where
PAGE_SIZE is greater than or equal to 32KB.
Signed-off-by: NAlexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This change updates igb so that it will correctly perform the descriptor
count calculation.  Previously it was taking NETDEV_FRAG_PAGE_MAX_SIZE
into account with isn't really correct since a different value is used to
determine the size of the pages used for TCP.  That is actually determined
by SKB_FRAG_PAGE_ORDER.
Signed-off-by: NAlexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

While testing I found that the testing for pfmemalloc in build_skb was
rather expensive.  I found the issue to be two-fold.  First we have to get
from the virtual address to the head page and that comes at the cost of
something like 11 cycles.  Then there is the cost for reading pfmemalloc out
of the head page which can be cache cold due to the fact that
put_page_testzero is likely invalidating the cache-line on one or more
CPUs as the fragments can be shared.

To avoid this extra expense I have added a pfmemalloc member to the
netdev_alloc_cache.  I then pushed pieces of __alloc_rx_skb into
__napi_alloc_skb and __netdev_alloc_skb so that I could rewrite them to
make use of the cached pfmemalloc value.  The result is that my perf traces
show a reduction from 9.28% overhead to 3.7% for the code covered by
build_skb, __alloc_rx_skb, and __napi_alloc_skb when performing a test with
the packet being dropped instead of being handed to napi_gro_receive.
Signed-off-by: NAlexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>