On Tue, 25.06.13 08:31, Brian Bockelman (bbock...@cse.unl.edu) wrote: > > On Jun 25, 2013, at 4:56 AM, Lennart Poettering <lenn...@poettering.net> > wrote: > > > On Tue, 25.06.13 02:21, Brian Bockelman (bbock...@cse.unl.edu) wrote: > > > >> A few questions came to mind which may provide interesting input > >> to your design process: > >> 1) I use cgroups heavily for resource accounting. Do you envision > >> me querying via dbus for each accounting attribute? Or do you > >> envision me querying for the cgroup name, then accessing the > >> controller statistics directly? > > > > Good question. Tejun wants systemd to cover that too. I am not entirely > > sure. I don't like the extra roundtrip for measuring the accounting > > bits. But maybe we can add a library that avoids the roundtrip, and > > simply provides you with high-level accounting values for cgroups. That > > way, for *changing* things you'd need to go via the bus, for *reading* > > things we'd give you a library that goes directly to the cgroupfs and > > avoids the roundtrip. > > I like this idea. Hopefully single-writer, multiple-reader is more > sustainable path forward. > > What about the notification APIs? We currently use the > memory.oom_control to get a notification when a job hits limits (this > allows us to know the job died due to memory issues, as the user code > itself typically just SIGSEGV's). Is subscribing to notifications > considered reading or writing in this case?
That sounds like another case for the library, i.e. is more considered reading. That said I think the current notification infrastructure of cgroup attributes is really really awful, so I am not to keen to support that right-away. Lennart -- Lennart Poettering - Red Hat, Inc. _______________________________________________ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel