Messages in this thread | | | Subject | Re: [RFC][PATCH] perf: sysfs type id | From | Peter Zijlstra <> | Date | Tue, 09 Nov 2010 23:22:27 +0100 |
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On Tue, 2010-11-09 at 23:11 +0100, Kay Sievers wrote: > On Tue, Nov 9, 2010 at 22:45, Peter Zijlstra <peterz@infradead.org> wrote: > > The below is a RFC patch adding dynamic type ids to perf. > > > > We need to represent PMUs in sysfs because we want to allow multiple > > (loadable) PMUs and need a way to identify them. > > > > This patch creates a new device class "pmu" and adds a single attribute > > "type" to it. This device attribute will expose the dynamic type id as > > required by perf_event_attr::type. > > > > The sysfs layout looks like: > > > > [root@westmere ~]# cd /sys/class/pmu/ > > Please use a 'bus_type' instead of 'class'. > > I'm very sure, some day, you'll need global attributes for the pmu > stuff, and class -- unlike bus -- has its own subdir where you can go > wild, without mixing things with the list-of-devices. :)
Having its own subdir sounds like a pro, so I'm somewhat confused. Also the pmu (or event_source as Ingo would like it getting called) seems like a class of devices not a bus.
USB/PCI/I2C/ISA are all buses.. pmu/event_source not so much, they are very different (sometimes even pure software) things that provide a common interface -- they generate events which we can count and sample.
/me dazed & confused, please do explain.
> No new stuff should use 'class', it's not extensible.
Hrm.. when I introduced the bdi stuff class was _the_ thing to use.
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