bpf: cpumap use ptr_ring_consume_batched

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Move ptr_ring dequeue outside loop, that allocate SKBs and calls network
stack, as these operations that can take some time. The ptr_ring is a
communication channel between CPUs, where we want to reduce/limit any
cacheline bouncing.

Do a concentrated bulk dequeue via ptr_ring_consume_batched, to shorten the
period and times the remote cacheline in ptr_ring is read

Batch size 8 is both to (1) limit BH-disable period, and (2) consume one
cacheline on 64-bit archs. After reducing the BH-disable section further
then we can consider changing this, while still thinking about L1 cacheline
size being active.

Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

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Jesper Dangaard Brouer 2019-04-12 17:07:32 +02:00 • committed by Alexei Starovoitov

parent 00967e84f7

commit 77361825bb

1 changed files with 11 additions and 10 deletions

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kernel/bpf/cpumap.c

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