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. Sebastian