Re: [PATCH 1/2] ixgbe: release lock for the duration of ixgbe_suspend_close()

From: Pavel Tatashin
Date: Thu May 03 2018 - 09:31:16 EST


Hi Alex,

> I'm not a fan of dropping the mutex while we go through
> ixgbe_close_suspend. I'm concerned it will result in us having a
> number of races on shutdown.

I would agree, but ixgbe_close_suspend() is already called without this
mutex from ixgbe_close(). This path is executed also during machine
shutdown but when kexec'ed. So, it is either an existing bug or there are
no races. But, because ixgbe_close() is called from the userland, and a
little earlier than ixgbe_shutdown() I think this means there are no races.


> If anything, I think we would need to find a replacement for the mutex
> that can operate at the per-netdev level if you are wanting to
> parallelize this.

Yes, if lock is necessary, it can be replaced in this place (and added to
ixgbe_close()) with something scalable.

Thank you,
Pavel