Merge branch 'Avoid-local_irq_save-and-use-napi_alloc_frag-where-possible'

Sebastian Andrzej says:

====================
Avoid local_irq_save() and use napi_alloc_frag() where possible

The first two patches remove local_irq_save() around
`netdev_alloc_cache' which does not work on -RT. Besides helping -RT it
whould benefit the users of the function since they can avoid disabling
interrupts and save a few cycles.
The remaining patches are from a time when I tried to remove
`netdev_alloc_cache' but then noticed that we still have non-NAPI
drivers using netdev_alloc_skb() and I dropped that idea. Using
napi_alloc_frag() over netdev_alloc_frag() would skip the not required
local_bh_disable() around the allocation.

v1…v2:
  - 1/7 + 2/7 use now "(in_irq() || irqs_disabled())" instead just
    "irqs_disabled()" to align with __dev_kfree_skb_any(). Pointed out
    by Eric Dumazet.

  - 6/7 has a typo less. Pointed out by Sergei Shtylyov.

  - 3/7 + 4/7 added acks from Ioana Radulescu.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>