Messages in this thread | | | Date | Wed, 2 Mar 2011 09:47:05 -0500 | From | Nick Bowler <> | Subject | Re: [PATCH 4/7] ufs: remove the BKL |
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On 2011-03-02 00:13 +0100, Arnd Bergmann wrote: > This introduces a new per-superblock mutex in UFS to replace > the big kernel lock. I have been careful to avoid nested > calls to lock_ufs and to get the lock order right with > respect to other mutexes, in particular lock_super. > > I did not make any attempt to prove that the big kernel > lock is not needed in a particular place in the code, > which is very possible. > > The code is still only compile-tested,
This isn't true anymore; I've been running with this patch (well, the previous versions thereof) for some time now. On the other hand, I don't use all of this driver's features.
> but it should at least be harmless on non-SMP systems, since the new > mutex is not taken on those.
I think this part of the patch is strange. It seems like a gratuitous difference between SMP/preempt and other systems to #if out the code that takes the mutex. This might make problems with the conversion fly under the radar longer because people with older systems won't encounter them.
-- Nick Bowler, Elliptic Technologies (http://www.elliptictech.com/)
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