Re: [PATCH v3 1/5] perf_event: introduce 'inject' event and get HZ

Ingo Molnar
2009-12-30T11:30:49Z

* Peter Zijlstra <peterz@infradead.org> wrote:

> OK so there is no sysconf() syscall and its all implemented in glibc, which
> is utter suckage.. will have to come up with something saner then.

I think integrating it into the perf stream of events would be the most
desirable approach - tooling could make use of it easily.

For data record (and hierarchy) description /debug/tracing/events/ would be
useful.

We dont want to actually 'activate' them in an 'event' fashion - but we could
use event IDs and the record format and the transport to describe and recover
the values.

For transport we could use the mmap ring-buffer and it would also be nice to
add (or resurrect) some 'quick & easy' read()/write() based transport. It a
bit like a value read-out from a counter - just here it's not a regular
counter but some sort of kernel-internal value that we want to provide.

Hm?

Ingo