From: Stefan Rompf <srompf@isg.de>
To: Michal Ostrowski <mostrows@watson.ibm.com>, netdev@oss.sgi.com
Subject: Re: Deadlock in sungem/ip_auto_config/linkwatch
Date: Mon, 5 Jan 2004 15:50:50 +0100 [thread overview]
Message-ID: <200401051550.51063.srompf@isg.de> (raw)
In-Reply-To: <1073307882.2041.98320.camel@brick.watson.ibm.com>
Am Montag, 05. Januar 2004 14:07 schrieb Michal Ostrowski:
> ic_open_devs grabs rtnl_sem with an rtnl_shlock() call.
>
> The sungem driver at some point calls gem_init_one, which calls
> netif_carrier_*, which in turn calls schedule_work (linkwatch_event).
>
> linkwatch_event in turn needs rtnl_sem.
Good catch! The sungem driver shows clearly that we need some way to remove
queued work without scheduling and waiting for other events.
I will change the linkwatch code to use rtnl_shlock_nowait() and backoff and
retry in case of failure this week. Call it a workaround, but it increases
overall system stability.
Btw, what is the planned difference between rtnl_shlock() and rtnl_exlock()?
Even though the later is a null operation right now, I don't want to hold
more locks than needed in the linkwatch code.
Stefan
--
"doesn't work" is not a magic word to explain everything.
next prev parent reply other threads:[~2004-01-05 14:50 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-01-05 13:07 Deadlock in sungem/ip_auto_config/linkwatch Michal Ostrowski
2004-01-05 14:50 ` Stefan Rompf [this message]
2004-01-05 16:19 ` Michal Ostrowski
2004-01-05 16:50 ` Stefan Rompf
2004-01-05 19:02 ` David S. Miller
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