[dpdk-stable] [PATCH v2] net/ixgbe: fix busy polling while fiber link update

[Zhang, Qi Z]

> -----Original Message-----
> From: Ilya Maximets [mailto:i.maximets at samsung.com]
> Sent: Thursday, November 1, 2018 11:05 AM
> To: dev at dpdk.org; Zhang, Qi Z <qi.z.zhang at intel.com>
> Cc: Lu, Wenzhuo <wenzhuo.lu at intel.com>; Ananyev, Konstantin
> <konstantin.ananyev at intel.com>; Laurent Hardy
> <laurent.hardy at 6wind.com>; Wei Dai <wei.dai at intel.com>; Yigit, Ferruh
> <ferruh.yigit at intel.com>; Ilya Maximets <i.maximets at samsung.com>;
> stable at dpdk.org
> Subject: [PATCH v2] net/ixgbe: fix busy polling while fiber link update
> 
> If the multispeed fiber link is in DOWN state, ixgbe_setup_link could take
> around a second of busy polling. This is highly inconvenient for the case
> where single thread periodically checks the link statuses. For example, OVS
> main thread periodically updates the link statuses and hangs for a really long
> time busy waiting on ixgbe_setup_link() for a DOWN fiber ports. For case
> with 3 down ports it hangs for a 3 seconds and unable to do anything
> including packet processing.
> Fix that by shifting that workaround to a separate thread by alarm handler
> that will try to set up link if it is DOWN.
> 
> Fixes: c12d22f65b13 ("net/ixgbe: ensure link status is updated")
> CC: stable at dpdk.org
> 
> Signed-off-by: Ilya Maximets <i.maximets at samsung.com>

Applied to dpdk-next-net-intel.

Thanks
Qi