Commit 6342ca64 authored Dec 11, 2018 by Prashant Bhole Committed by David S. Miller Dec 14, 2018

tun: replace get_cpu_ptr with this_cpu_ptr when bh disabled



tun_xdp_one() runs with local bh disabled. So there is no need to
disable preemption by calling get_cpu_ptr while updating stats. This
patch replaces the use of get_cpu_ptr() with this_cpu_ptr() as a
micro-optimization. Also removes related put_cpu_ptr call.

Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Prashant Bhole <bhole_prashant_q7@lab.ntt.co.jp>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent c2c79a32

drivers/net/tun.c

+4 −2

Original line number	Diff line number	Diff line
		@@ -2495,12 +2495,14 @@ build:
		skb_record_rx_queue(skb, tfile->queue_index);
		netif_receive_skb(skb);

		stats = get_cpu_ptr(tun->pcpu_stats);
		/* No need for get_cpu_ptr() here since this function is
		* always called with bh disabled
		*/
		stats = this_cpu_ptr(tun->pcpu_stats);
		u64_stats_update_begin(&stats->syncp);
		stats->rx_packets++;
		stats->rx_bytes += datasize;
		u64_stats_update_end(&stats->syncp);
		put_cpu_ptr(stats);

		if (rxhash)
		tun_flow_update(tun, rxhash, tfile);

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