Messages in this thread | | | From | Con Kolivas <> | Subject | Re: [PATCH][2/4] sched: add discrete weighted cpu load function | Date | Wed, 15 Mar 2006 09:50:40 +1100 |
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On Wednesday 15 March 2006 09:45, Peter Williams wrote: > Con Kolivas wrote: > > I haven't checked but gcc may well inline weighted_cpuload anyway? > > It may be doing so for internal uses inside sched.c but I'm pretty sure > that it won't for external calls.
Hmm I investigated briefly and only C99 inlining (whatever that means) will allow me to locally inline and export as well. It would do so if I specified -finline-functions which is not our default at all in the kernel (we only recently disable -fnoinline-functions I believe). Anyway checking positively shows me this on gcc 4.1.0:
0xc0111283 <find_busiest_queue+83>: call 0xc0110dc0 <weighted_cpuload>
So no, it doesn't get inlined.
> > The way you're suggesting adds a function that is never used by anything > > but swap prefetch which would then need to be 'ifdef'ed out to not be > > needlessly built on every system. Adding ifdefs is frowned upon already, > > and to have an mm/ specific ifdef in sched.c would be rather ugly. > > Sometimes ugliness is the best option.
I spent quite some time trying to find the least cost way to do this without uglifying code. I don't feel strongly about just how to do it though. Comments from Andrew and Ingo would be most welcome on this matter.
Cheers, Con - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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