From: Stephen Hemminger <shemminger@vyatta.com>
To: David Miller <davem@davemloft.net>
Cc: netdev@vger.kernel.org
Subject: ethtool physical identify vs netlink locking?
Date: Tue, 29 Mar 2011 13:52:52 -0700 [thread overview]
Message-ID: <20110329135252.116bf5e0@s6510> (raw)
Right now if an administrator uses the ethtool function to identify network
interface, the netlink lock can be held indefinitely. In other words, doing
"ethtool -p eth1" will stop all other netlink activity. This is bad, imagine
the case of an operator doing that to find a NIC in a rack, and because of
the netlink lockout all routing daemon activity stops.
There are several possible solutions but most involve fixing all the device
drivers (24). Options:
1. Have device driver drop and reacquire rtnl() while blinking
2. Have ethtool core drop rtnl before calling device driver
3. Add per-device ethtool rtnl lock
#1 is the least disruption
#2 means additional locking maybe required for each device driver
#3 seems like excessive overhead.
Comments?
next reply other threads:[~2011-03-29 20:52 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-03-29 20:52 Stephen Hemminger [this message]
2011-03-30 0:07 ` ethtool physical identify vs netlink locking? Ben Hutchings
2011-03-30 0:13 ` David Miller
2011-03-30 0:23 ` Stephen Hemminger
2011-03-30 1:35 ` Michał Mirosław
2011-03-30 6:29 ` Stephen Hemminger
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