Messages in this thread | | | From | Rusty Russell <> | Subject | Re: [PATCH] per-cpu areas for 2.5.3-pre6 | Date | Thu, 31 Jan 2002 09:45:45 +1100 |
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In message <20020130002204.A4480@are.twiddle.net> you write: > Have we already forgotten the ppc reloc flamefest? Better > written as > > #define per_cpu(var, cpu) \ > ({ __typeof__(&(var)) __ptr; \ > __asm__ ("" : "=g"(__ptr) \ > : "0"((void *)&(var) + per_cpu_offset(cpu))); \ > *__ptr; })
"better". Believe me, I was fully aware, but I refuse to write such crap unless *proven* to be required.
> > +/* Created by linker magic */ > > +extern char __per_cpu_start, __per_cpu_end; > [...] > > + per_cpu_size = ((&__per_cpu_end - &__per_cpu_start) + PAGE_SIZE-1) > > Will fail on targets (e.g. alpha and mips) that have a notion of a > "small data area" that can be addressed with special relocs. > > Better written as > > extern char __per_cpu_start[], __per_cpu_end[]; > per_cpu_size = (__per_cpu_end - __per_cpu_start) ...
I agree that this is much better. But do not understand what small relocs have to do with simple address arithmetic? You've always been right before: what am I missing?
Rusty. -- Anyone who quotes me in their sig is an idiot. -- Rusty Russell. - 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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