vmxnet3: avoid xmit reset due to a race in vmxnet3

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The field txNumDeferred is used by the driver to keep track of the number
of packets it has pushed to the emulation. The driver increments it on
pushing the packet to the emulation and the emulation resets it to 0 at
the end of the transmit.

There is a possibility of a race either when (a) ESX is under heavy load or
(b) workload inside VM is of low packet rate.

This race results in xmit hangs when network coalescing is disabled. This
change creates a local copy of txNumDeferred and uses it to perform ring
arithmetic.

Reported-by: Noriho Tanaka <ntanaka@vmware.com>
Signed-off-by: Ronak Doshi <doshir@vmware.com>
Acked-by: Shrikrishna Khare <skhare@vmware.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

...

This commit is contained in:

Ronak Doshi 2018-03-16 14:47:54 -07:00 • committed by David S. Miller

parent 78f1b04fa2

commit 7a4c003d69

2 changed files with 10 additions and 7 deletions

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13

drivers/net/vmxnet3/vmxnet3_drv.c

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4

drivers/net/vmxnet3/vmxnet3_int.h

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