Messages in this thread | | | Date | Tue, 18 Nov 2008 10:02:50 +0800 | From | Li Zefan <> | Subject | Re: [patch 0/4] [RFC] Another proportional weight IO controller |
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Vivek Goyal wrote: > On Fri, Nov 14, 2008 at 02:44:22PM -0800, Nauman Rafique wrote: >> In an attempt to make sure that this discussion leads to >> something useful, we have summarized the points raised in this >> discussion and have come up with a strategy for future. >> The goal of this is to find common ground between all the approaches >> proposed on this mailing list. >> >> 1 Start with Satoshi's latest patches. > > I have had a brief look at both Satoshi's patch and bfq. I kind of like > bfq's patches for keeping track of per cgroup, per queue data structures. > May be we can look there also. > >> 2 Do the following to support propotional division: >> a) Give time slices in proportion to weights (configurable >> option). We can support both priorities and weights by doing >> propotional division between requests with same priorities. >> 3 Schedule time slices using WF2Q+ instead of round robin. >> Test the performance impact (both throughput and jitter in latency). >> 4 Do the following to support the goals of 2 level schedulers: >> a) Limit the request descriptors allocated to each cgroup by adding >> functionality to elv_may_queue() >> b) Add support for putting an absolute limit on IO consumed by a >> cgroup. Such support exists in dm-ioband and is provided by Andrea >> Righi's patches too. > > Does dm-iobnd support abosolute limit? I think till last version they did > not. I have not check the latest version though. >
No, dm-ioband still provides weight/share control only. Only Andrea Righi's patches support absolute limit.
>> c) Add support (configurable option) to keep track of total disk >> time/sectors/count >> consumed at each device, and factor that into scheduling decision >> (more discussion needed here) >> 5 Support multiple layers of cgroups to align IO controller behavior >> with CPU scheduling behavior (more discussion?) >> 6 Incorporate an IO tracking approach which re-uses memory resource >> controller code but is not dependent on it (may be biocgroup patches from >> dm-ioband can be used here directly) >> 7 Start an offline email thread to keep track of progress on the above >> goals. >> >> Please feel free to add/modify items to the list >> when you respond back. Any comments/suggestions are more than welcome. >>
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