Re: [dpdk-stable] [dpdk-dev] [PATCH v2] net/ixgbe: fix blocking system events

[Thomas Monjalon <thomas@monjalon.net>]

21/02/2020 09:19, Zhu, TaoX:
> Hi Thomas
>  
> Thank you for your correction spelling error of 'cancel'.
> 
> Indeed it is not the best solution by creating a thread. I refer to the same solution with Linux kernel driver. Linux kernel driver manages link status by using a thread. Maybe we can figure out another better solution to fix this problem but it may take much more time. At this time, 20.02 formal release is coming and this problem affect some basic library. 
> Tks for your understanding.

I understand, that's why I already accepted this patch in mainline (while fixing typo).

Please it would be really appreciated to work on a better solution.



> > -----Original Message-----
> > From: Thomas Monjalon [mailto:thomas@monjalon.net]
> > Sent: Thursday, February 20, 2020 11:37 PM
> > To: Ye, Xiaolong <xiaolong.ye@intel.com>; Zhu, TaoX <taox.zhu@intel.com>;
> > Yigit, Ferruh <ferruh.yigit@intel.com>
> > Cc: dev@dpdk.org; Ananyev, Konstantin <konstantin.ananyev@intel.com>;
> > Lu, Wenzhuo <wenzhuo.lu@intel.com>; stable@dpdk.org
> > Subject: Re: [dpdk-dev] [PATCH v2] net/ixgbe: fix blocking system events
> > 
> > 17/02/2020 14:01, Ferruh Yigit:
> > > On 2/15/2020 3:41 PM, Ye Xiaolong wrote:
> > > > On 01/15, taox.zhu@intel.com wrote:
> > > >> From: Zhu Tao <taox.zhu@intel.com>
> > > >>
> > > >> IXGBE link status task use rte alarm thread in old implementation.
> > > >
> > > > s/use/uses
> > > >
> > > >> Sometime ixgbe link status task takes up to 9 seconds. This will
> > > >> severely affect the rte-alarm-thread-dependent a task in the
> > > >> system, like interrupt or hotplug event. So replace with a
> > > >
> > > > s/a/an
> > > >
> > > >> independent thread which has the same thread affinity settings as
> > > >> rte interrupt.
> > > >>
> > > >> Fixes: 0408f47b ("net/ixgbe: fix busy polling while fiber link
> > > >> update")
> > > >
> > > > Should be:
> > > >
> > > > Fixes: 0408f47ba4d6 ("net/ixgbe: fix busy polling while fiber link
> > > > update")
> > > >
> > > >> Cc: stable@dpdk.org
> > > >>
> > > >
> > > > Applied to dpdk-next-net-intel with Konstantin's ack, Thanks.
> > > >
> > >
> > > Shared build is failing because of missing pthread library, fixing
> > > while merging to next-net:
> > 
> > One more thing looks strange in this patch:
> > 	ixgbe_dev_cannel_link_thread
> > Should it be
> > 	ixgbe_dev_cancel_link_thread
> > ?
> > 
> > Note: I looked at it because I am not sure multiplying the interrupt threads is
> > a good idea.
> > Basically the link status management is too long in this driver.
> > Instead of fixing the root cause, you move the annoying workload
> > somewhere else. But it is still there...
> > 
> > Please could you work on a long term fix?
> > 
> 
>