On Thu, 13 Nov 2008 12:10:19 +0900 (JST) Ryo Tsuruta <ryov@xxxxxxxxxxxxx> wrote: > Hi everyone, > > This is a new release of dm-ioband and bio-cgroup. With this release, > the overhead of bio-cgroup is significantly reduced and the accuracy > of block I/O tracking is much improved. These patches are for > 2.6.28-rc2-mm1. > >From my point of view, a way to record bio_cgroup_id to page_cgroup is quite neat and nice. My concern is "bio_cgroup_id". It's provided only for bio_cgroup. In this summer, I tried to add swap_cgroup_id only for mem+swap controller but commenters said "please provide "id and lookup" in cgroup layer, it should be useful." And I agree them. (and postponed it ;) Could you try "id" in cgroup layer ? How do you think, Paul and others ? That's my only concern and if I/O controller people decides to live with this bio tracking infrastracture, == page -> page_cgroup -> bio_cgroup_id == I have no objections. And enqueue necessary changes to my queue. Thanks, -Kame > Enjoy it! > > dm-ioband > ========= > > Dm-ioband is an I/O bandwidth controller implemented as a > device-mapper driver, which gives specified bandwidth to each job > running on the same block device. A job is a group of processes > or a virtual machine such as KVM or Xen. > I/O throughput on dm-ioband is excellent not only on SATA storage > but on SDD, which as good as the one without dm-ioband. > > Changes from the previous release: > - Fix a bug that create_workqueue() is called during spin lock > when creating a new ioband group. > - A new tunable parameter "carryover" is added, which specifies > how many tokens an ioband group can keep for the future use > when the group isn't so active. > > TODO: > - Other policies to schedule BIOs. > - Policies which fits SSD. > e.g.) > - Guarantee response time. > - Guarantee throughput. > - Policies which fits Highend Storage or hardware raid storage. > - Some LUNs may share the same bandwidth. > - Support WRITE_BARRIER when the device-mapper layer supports it. > - Implement the algorithm of dm-ioband in the block I/O layer > experimentally. > > bio-cgroup > ========== > > Bio-cgroup is a BIO tracking mechanism, which is implemented on the > cgroup memory subsystem. With the mechanism, it is able to determine > which cgroup each of bio belongs to, even when the bio is one of > delayed-write requests issued from a kernel thread such as pdflush. > > Changes from the previous release: > - This release is a new implementation. > - This is based on the new design of the cgroup memory controller > framework, which pre-allocates all cgroup-page data structures to > reduce the overhead. > - The overhead to trace block I/O requests is much smaller than that > of the previous one. This is done by making every page have the id > of its corresponding bio-cgroup instead of the pointer to it and > most of spin-locks and atomic operations are gone. > - This implementation uses only 4 bytes per page for I/O tracking > while the previous version uses 12 bytes on a 32 bit machine and 24 > bytes on a 64 bit machine. > - The accuracy of I/O tracking is improved that it can trace I/O > requests even when the processes which issued these requests get > moved into another bio-cgroup. > - Support bounce buffers tracking. They will have the same bio-cgroup > owners as the original I/O requests. > > TODO: > - Support to track I/O requests that will be generated in Linux > kernel, such as those of RAID0 and RAID5. > > A list of patches > ================= > > The following is a list of patches: > > [PATCH 0/8] I/O bandwidth controller and BIO tracking > [PATCH 1/8] dm-ioband: Introduction > [PATCH 2/8] dm-ioband: Source code and patch > [PATCH 3/8] dm-ioband: Document > [PATCH 4/8] bio-cgroup: Introduction > [PATCH 5/8] bio-cgroup: The new page_cgroup framework > [PATCH 6/8] bio-cgroup: The body of bio-cgroup > [PATCH 7/8] bio-cgroup: Page tracking hooks > [PATCH 8/8] bio-cgroup: Add a cgroup support to dm-ioband > > Please see the following site for more information: > Linux Block I/O Bandwidth Control Project > http://people.valinux.co.jp/~ryov/bwctl/ > > Thanks, > Ryo Tsuruta > -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
