In message <Pine.LNX.4.44.0201301259520.11802-100000@waste.org> you write:
> I still think that tracking per_cpu_offset in task struct to eventually
> replace current->processor is a win. Basically everyone except Sparc goes
> through current anyway for smp_processor_id and Sparc caches current in a
> register. Please elucidate your reference to "arch-specific tradeoffs".
Placing useful information in the task struct is a hack. A useful
hack on the register-starved x86, of course. PPC64 will probably use
a register, too.
BTW, apologies for my previous accusations of not reading the
thread. Your reply predated mine by 12 hours:
http://www.ozlabs.org/~rusty/Stupidity.html#9
> Also, it'd be nice to unmap the original copy of the area or at least
> poison it to catch silent references to var without going through
> this_cpu, which will probably prove very hard to find. If there were a way
> to do this at the C source level and catch such things at compile time,
> that'd be even better, but I can't see a way to do it without grotty
> macros.
My first cut did this, with a macro:
DECLARE_PER_CPU(int x);
This allows you to munge x into x__per_cpu, to catch "bare"
references. But I decided against it for two reasons: firstly
__per_cpu_data is nicer, and secondly my proc/sys rewrite can handle
per-cpu data easily if the name is valid.
In practice, grep should be sufficient.
Cheers!
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/
This archive was generated by hypermail 2b29 : Thu Jan 31 2002 - 21:01:27 EST