On Fr, 08.06.18 17:54, Zhangyanfei (YF) ([email protected]) wrote: > Hello > > The linux kernel has support all Intel RDT(Resource Director Technology)[1] > features, > via a filesystem resctrlfs [2]. > Libvirt has introduced CAT into it snice v4.1.0 [3].And Marcelo tried to post > a > patch to add CAT support into systemd before but the way the patch did > (gluing a python tool) > is not acceptable by the maintainer [4]. > > I think including RDT support in systemd is necessary because we should have a > central place to control how we use the RDT features. We should have a global > control > over the resctrlfs when applications in the system want to use RDT. > > My initial idea is: > 1. resctrlfs should be mounted/unmounted in systemd just like > cgroupfs.
sounds fine to me though this does make me wonder: what's the reason this stuff is not exposed via cgroups anyway? why is this form of resource management separate from cgroups resource mgmt? > 2. Systemd should lock/unlock resctrlfs when ncessary to avoid > contending. what do you mean by lock/unlock? Note that i have no understanding of RDT whatsoever, hence if "lock"/"unlock" is some RDT term in this context, please elaborate. > 3. Support RDT allocation control in *slice* unit instead of *service* unit. > This is > different from what Marcelo did in his patch. resctrlfs has some > limitations due to > the hardware: > a.The directory for allocation (CAT/MBA) is limited. In my machine, the > max number > is only 8, so we can only have 8 groups at most to use the RDT > allocation control. > b.We can only create directories for allocation in the root directory, no > nesting. > So if we want to use the RDT to control shared resources in the whole > system, > we must group tasks/services together. I'd probably permit these settings on all of slice, service, scope units, but preferably apply them to units close to the root. > Below is the RFC patch that adding CAT in systemd. It only including > implementations related > to 3 in the above idea. Please always submit patches through github these days, as PRs. The review tools are much much nicer there... > L3Cat=L3:1=001 We generally expose settings in normalized, readable, user friendly syntax. The above appears very cryptic and abbreviated to me. I'll take readability any day over cryptic appreviations. > + EXIT_RESCTRL, Why is this called "resctrl" btw? That's such an extremely generic name... Lennart -- Lennart Poettering, Red Hat _______________________________________________ systemd-devel mailing list [email protected] https://lists.freedesktop.org/mailman/listinfo/systemd-devel
