Messages in this thread | | | Date | Mon, 05 Aug 2013 11:51:28 -0700 | From | "H. Peter Anvin" <> | Subject | Re: [RFC] gcc feature request: Moving blocks into sections |
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On 08/05/2013 11:49 AM, Steven Rostedt wrote: > On Mon, 2013-08-05 at 11:29 -0700, H. Peter Anvin wrote: > >> Traps nest, that's why there is a stack. (OK, so you don't want to take >> the same trap inside the trap handler, but that code should be very >> limited.) The trap instruction just becomes very short, but rather >> slow, call-return. >> >> However, when you consider the cost you have to consider that the >> tracepoint is doing other work, so it may very well amortize out. > > Also, how would you pass the parameters? Every tracepoint has its own > parameters to pass to it. How would a trap know what where to get "prev" > and "next"? >
How do you do that now?
You have to do an IP lookup to find out what you are doing.
(Note: I wonder how much the parameter generation costs the tracepoints.)
-hpa
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