Messages in this thread | | | Subject | Re: [PATCH RFC 0/3] Static calls | From | Andy Lutomirski <> | Date | Fri, 9 Nov 2018 11:05:51 -0800 |
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> On Nov 9, 2018, at 10:42 AM, Steven Rostedt <rostedt@goodmis.org> wrote: > > On Fri, 9 Nov 2018 10:41:37 -0600 > Josh Poimboeuf <jpoimboe@redhat.com> wrote: > >>> On Fri, Nov 09, 2018 at 09:21:39AM -0600, Josh Poimboeuf wrote: >>>> On Fri, Nov 09, 2018 at 07:16:17AM -0800, Andy Lutomirski wrote: >>>>> On Thu, Nov 8, 2018 at 11:28 PM Ingo Molnar <mingo@kernel.org> wrote: >>>>> >>>>> >>>>> All other usecases are bonus, but it would certainly be interesting to >>>>> investigate the impact of using these APIs for tracing: that too is a >>>>> feature enabled everywhere but utilized only by a small fraction of Linux >>>>> users - so literally every single cycle or instruction saved or hot-path >>>>> shortened is a major win. >>>> >>>> For tracing, we'd want static_call_set_to_nop() or something like that, right? >>> >>> Are we talking about tracepoints? Or ftrace? >> >> Since ftrace changes calls to nops, and vice versa, I assume you meant >> ftrace. I don't think ftrace is a good candidate for this, as it's >> inherently more flexible than this API would reasonably allow. >> > > Not sure what Andy was talking about, but I'm currently implementing > tracepoints to use this, as tracepoints use indirect calls, and are a > prime candidate for static calls, as I showed in my original RFC of > this feature. > >
Indeed.
Although I had assumed that tracepoints already had appropriate jump label magic.
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