Commit 6e11d157 authored Feb 24, 2020 by Amritha Nambiar Committed by David S. Miller Feb 26, 2020

net: Fix Tx hash bound checking

Fixes the lower and upper bounds when there are multiple TCs and
traffic is on the the same TC on the same device.

The lower bound is represented by 'qoffset' and the upper limit for
hash value is 'qcount + qoffset'. This gives a clean Rx to Tx queue
mapping when there are multiple TCs, as the queue indices for upper TCs
will be offset by 'qoffset'.

v2: Fixed commit description based on comments.

Fixes: 1b837d48 ("net: Revoke export for __skb_tx_hash, update it to just be static skb_tx_hash")
Fixes: eadec877 ("net: Add support for subordinate traffic classes to netdev_pick_tx")
Signed-off-by: Amritha Nambiar <amritha.nambiar@intel.com>
Reviewed-by: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Reviewed-by: Sridhar Samudrala <sridhar.samudrala@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent a8e41f60

net/core/dev.c

+2 −0

Original line number	Diff line number	Diff line
		@@ -3076,6 +3076,8 @@ static u16 skb_tx_hash(const struct net_device *dev,

		if (skb_rx_queue_recorded(skb)) {
		hash = skb_get_rx_queue(skb);
		if (hash >= qoffset)
		hash -= qoffset;
		while (unlikely(hash >= qcount))
		hash -= qcount;
		return hash + qoffset;

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