Messages in this thread | | | Date | Sat, 05 Jan 2008 12:02:37 -0800 | From | Arjan van de Ven <> | Subject | Re: [patch 1/3] move WARN_ON() out of line |
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Jeremy Fitzhardinge wrote: > > Yeah, that seems reasonable if you're optimising for overall size. Did > you count the difference of including the function name? We decided not > to include it for BUG because its usefulness/size tradeoff didn't seem > terribly important.
in the WARN_ON case it's not there either, based on Ingo's idea we do a kallsyms lookup of __builtin_return_address(0) .. same data, less memory.
> But my goal was actually to reduce icache pollution, so by my reckoning > code bytes were much more expensive than data ones, so putting all BUG > information in a separate section makes those bytes much less > significant than putting anything inline in code. Also, the trap for > WARN_ON would be smaller than BUG, because it wouldn't need the spurious > infinite loop needed to make gcc understand the control flow of a BUG. > > On the other hand, you could put the call to out of line warning > function in a separate section to achieve the same effect.
yeah and gcc even has a compiler option for that. Doubt it's really worth it, we're still talking a few bytes here ;)
> > J
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