Messages in this thread | | | Date | Tue, 29 Apr 2008 00:44:38 +0200 | From | Ingo Molnar <> | Subject | Re: [patch 0/2] Immediate Values - jump patching update |
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* H. Peter Anvin <hpa@zytor.com> wrote:
> What I'm proposing is: > > > [ .... fastpath head ...... ] > > [ .... 5-byte CALL .......... ] ---> NOP-ed out > > [ .... fastpath tail .......... ] > > [ ............................. ] > > The call site is created with an asm() statement as opposed to a gcc > function call; it is up to the logging function to take the state and > mangle it into whatever format it wants to; the debugging information > (e.g. DWARF) should tell it all it needs to know about how the > register/memory state maps onto the C state. This mapping can either > be done online, with a small piece of dynamic code, or offline > (although offline makes it tricky to know what memory tems to gather.)
that would be rather impractical as we'd force DEBUG_INFO builds on anyone (it's HUGE) just to do some trivial tracing. Look at the ftrace plugin usage model - it wants to be widely available and easy to use.
Ingo
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