Messages in this thread | | | Subject | Re: [RFC][PATCH 2/3] perf: Take a hot regs snapshot for trace events | From | Peter Zijlstra <> | Date | Wed, 03 Mar 2010 18:16:35 +0100 |
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On Wed, 2010-03-03 at 12:07 -0500, Steven Rostedt wrote: > oops, my bad :-), I thought this was in the x86 arch directory. For the > University, I was helping them with adding trace points for page faults > when I came across this in arch/x86/mm/fault.c: > > perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, 0, regs, address); > > > This is what I actually was wondering about. Why is it a "perf only" > trace point instead of a TRACE_EVENT()?
Because I wanted to make perf usable without having to rely on funny tracepoints. That is, I am less worried about committing software counters to ABI than I am about TRACE_EVENT(), which still gives me a terribly uncomfortable feeling.
Also, building with all CONFIG_TRACE_*=n will still yield a usable perf, which is something the embedded people might fancy, all that TRACE stuff adds lots of code.
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