On Thu, Nov 13, 2008 at 10:58:34AM -0500, Vivek Goyal wrote: > On Thu, Nov 13, 2008 at 06:05:58PM +0900, Ryo Tsuruta wrote: > > Hi, > > > > From: vgoyal@xxxxxxxxxx > > Subject: [patch 0/4] [RFC] Another proportional weight IO controller > > Date: Thu, 06 Nov 2008 10:30:22 -0500 > > > > > Hi, > > > > > > If you are not already tired of so many io controller implementations, here > > > is another one. > > > > > > This is a very eary very crude implementation to get early feedback to see > > > if this approach makes any sense or not. > > > > > > This controller is a proportional weight IO controller primarily > > > based on/inspired by dm-ioband. One of the things I personally found little > > > odd about dm-ioband was need of a dm-ioband device for every device we want > > > to control. I thought that probably we can make this control per request > > > queue and get rid of device mapper driver. This should make configuration > > > aspect easy. > > > > > > I have picked up quite some amount of code from dm-ioband especially for > > > biocgroup implementation. > > > > > > I have done very basic testing and that is running 2-3 dd commands in different > > > cgroups on x86_64. Wanted to throw out the code early to get some feedback. > > > > > > More details about the design and how to are in documentation patch. > > > > > > Your comments are welcome. > > > > 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. 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. Thanks Vivek > > - Put uneven I/O loads. Processes, which belong to a cgroup which is > > given a smaller weight than another cgroup, put heavier I/O load > > like the following. > > > > echo 1024 > /cgroup/bio/test1/bio.shares > > echo 8192 > /cgroup/bio/test2/bio.shares > > > > echo $$ > /cgroup/bio/test1/tasks > > dd if=/somefile1-1 of=/dev/null & > > dd if=/somefile1-2 of=/dev/null & > > ... > > dd if=/somefile1-100 of=/dev/null > > echo $$ > /cgroup/bio/test2/tasks > > dd if=/somefile2-1 of=/dev/null & > > dd if=/somefile2-2 of=/dev/null & > > ... > > dd if=/somefile2-10 of=/dev/null & > > I have not tried this case. > > 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 have had a very brief look at BFQ's hierarchical proportional > weight/priority IO control and it looks good. May be we can adopt it for > other IO schedulers also. > > Thanks > Vivek _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/virtualization
