Messages in this thread | | | Date | Wed, 2 Mar 2011 10:48:42 -0500 | From | Nick Bowler <> | Subject | Re: [PATCH 4/7] ufs: remove the BKL |
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On 2011-03-02 16:08 +0100, Arnd Bergmann wrote: > On Wednesday 02 March 2011, Nick Bowler wrote: > > On 2011-03-02 00:13 +0100, Arnd Bergmann wrote: > > > 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. > > I'll updated the comment. Can I add your Tested-by tag?
Sure.
> > > 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. > > I agree it is strange, but the mutex has some serious performance impact > that I wanted to minimize on the systems where we know it is not needed. > The BKL was only active on those systems, so we know that non-SMP > non-preempt kernels don't need the mutex.
Fair enough. If it hurts too much to run this code when it's not needed, then I guess it makes sense to leave it out.
-- Nick Bowler, Elliptic Technologies (http://www.elliptictech.com/)
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