From mboxrd@z Thu Jan  1 00:00:00 1970
From: erik quanstrom <quanstro@quanstro.net>
Date: Sat,  6 Feb 2010 11:16:56 -0500
To: 9fans@9fans.net
Message-ID: <8958c1578747eede379d83afdf918114@ladd.quanstro.net>
In-Reply-To: <20100206161207.GA31545@centaur.acm.jhu.edu>
References: <20100206161207.GA31545@centaur.acm.jhu.edu>
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Subject: Re: [9fans] kenfs question?
Topicbox-Message-UUID: ce88c0b4-ead5-11e9-9d60-3106f5b1d025

> ilock() (pc/lock.c) calls splhi() and then calls lock(). If that lock were contended,
> how would the system not stop? And on a UP system, if you're inside an splhi() block,
> why would you need to take an uncontended lock?

good question.  on a up system, splhi() is sufficient.  on a mp
system, the losing process will spin until the winning process
is finished.

ken fs does need to return to its mp roots.

- erik