Messages in this thread | | | Subject | Re: Nick's vfs-scalability patches ported to 2.6.33-rt | From | john stultz <> | Date | Wed, 03 Mar 2010 20:05:11 -0800 |
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On Thu, 2010-03-04 at 14:33 +1100, Nick Piggin wrote: > On Wed, Mar 03, 2010 at 03:31:30PM -0800, john stultz wrote: > > On Fri, 2010-02-26 at 17:01 +1100, Nick Piggin wrote: > > > On Thu, Feb 25, 2010 at 09:53:28PM -0800, john stultz wrote: > > > > Hey Thomas, Nick, > > > > I just wanted to let you know I've just finished forward porting Nick's > > > > patches to 2.6.33-rc8-rt2. Luckily my forward port of Nick's patches to > > > > 2.6.33 applies on top of the -rt tree without any collisions, and I've > > > > added a handful of maybe sketchy fixups to get it working with -rt. > > > > > > > > You can find the patchset here: > > > > http://sr71.net/~jstultz/dbench-scalability/patches/2.6.33-rc8-rt2/vfs-scale.33-rt.tar.bz2 > > > > > > > > Here's a chart showing how much these patches help dbench numbers on > > > > ramfs: > > > > http://sr71.net/~jstultz/dbench-scalability/graphs/2.6.33/ramfs-dbench.png > > > > > > > > I've not done any serious stress testing with the patchset yet, but > > > > wanted to post it for your review. > > > > > > > > Nick: I'd appreciate any feedback as to if any of my forward porting has > > > > gone awry. I'm still very green with respect to the vfs, so I don't > > > > doubt there are some issues hiding here. > > > > > > BTW there are a few issues Al pointed out. We have to synchronize RCU > > > after unregistering a filesystem so d_ops/i_ops doesn't go away, and > > > mntput can sleep so we can't do it under RCU read lock. > > > > Does the following address this issue properly? > > As far as I could tell, yes that should solve the code reference > problem. I don't see a problem with synchronizing RCU here.
Good to hear! Thanks for the review Nick!
Thomas: I ran a number of kernel-bench and dbench stress tests on this today and I've not seen any issues, so unless Nick has other issues, I think it should be ok to pull into -rt.
You can grab the full patchset that builds ontop of 2.6.33-rt4 here: http://sr71.net/~jstultz/dbench-scalability/patches/2.6.33-rt4/vfs-scale.33-rt.tar.bz2
thanks -john
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