On Sat, 2011-05-28 at 03:56 +0800, Peter Zijlstra wrote: > On Fri, 2011-05-27 at 16:26 +0800, Zhang Rui wrote: > > > > > Currently there isn't a way to expose the events in sysfs, but we do > > > want that, its mostly a matter of getting all involved parties to agree > > > on a format and implementing it. > > > > > I talked with Lin Ming just now, and he said that it should work in this > > way: > > First, only one pmu for RAPL interfaces, with four different kinds of > > events, pkg/core/uncore/dram, > > and the sysfs I/F is: > > /sys/bus/event_source/devices/rapl/---|---type > > |---pkg > > |---core > > |---uncore > > |---dram > > Actually something like: > > /sys/bus/.../rapl/ -- | -- type > | -- events -- | -- pkg > | -- core > | ... > > was one of the latest proposals, but then someone (can't remember who) > offered the opinion that having sub-groups of event might also be > wanted. > > Furthermore a 'format' file was proposed which ought to contain a > description of how to compose a ::config value, but we never got around > to discussing a valid/useful syntax that could express all existing > cases (let alone be future proof). > > > to use it, users can issue something like: > > perf stat -P rapl -e pkg/core/uncore/dram foo > > so that event->attr.type equals rapl_pmu.type and event->attr.config > > equals one of the rapl_domain_id. > > Right, something like that, or simply something like -e rapl:pkg, which > again reminds me that people were working on a full EBNF syntax for the > -e argument. > > > This sounds good. I can rewrite the code to work in this way, but it > > doesn't work for now, until both sysfs I/F and perf tool being ready, > > right? > > Right, so the only thing missing is the event bits (and some userspace > bits to use it all). The hardest part of it is getting those definitions > sorted, writing the patches shouldn't be too hard. > Okay. So should I finish the kernel code first, which just checks the event->attr.type/config value, no matter how they are passed to kernel? thanks, rui > > _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
