Messages in this thread | | | Date | Thu, 20 Nov 2008 18:20:53 +0900 (JST) | Subject | Re: [patch 0/4] [RFC] Another proportional weight IO controller | From | Ryo Tsuruta <> |
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Hi Vivek,
Sorry for late reply.
> > > Do you have any benchmark results? > > > I'm especially interested in the followings: > > > - Comparison of disk performance with and without the I/O controller patch. > > > > If I dynamically disable the bio control, then I did not observe any > > impact on performance. Because in that case practically it boils down > > to just an additional variable check in __make_request(). > > > > Oh.., I understood your question wrong. You are looking for what's the > performance penalty if I enable the IO controller on a device.
Yes, that is what I want to know.
> I have not done any extensive benchmarking. If I run two dd commands > without controller, I get 80MB/s from disk (roughly 40 MB for each task). > With bio group enabled (default token=2000), I was getting total BW of > roughly 68 MB/s. > > I have not done any performance analysis or optimizations at this point of > time. I plan to do that once we have some sort of common understanding about > a particular approach. There are so many IO controllers floating, right now > I am more concerned if we can all come to a common platform.
I understood the reason of posting the patch well.
> Ryo, do you still want to stick to two level scheduling? Given the problem > of it breaking down underlying scheduler's assumptions, probably it makes > more sense to the IO control at each individual IO scheduler.
I don't want to stick to it. I'm considering implementing dm-ioband's algorithm into the block I/O layer experimentally.
Thanks, Ryo Tsuruta
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