Messages in this thread | | | Date | Wed, 14 Mar 2007 18:57:01 -0700 | From | Jeremy Fitzhardinge <> | Subject | Re: [PATCH 0/8] x86 boot, pda and gdt cleanups |
| |
Rusty Russell wrote: > Hmm, this invalidated my assumption that write_gdt_entry is always a > write to this cpu's active gdt. Better fix is not to call it twice > anyway... >
No, I don't think that's true. I implemented the write_*_entry functions with the assumption they could be called either on setup or on an in-use entry. I think its good policy to use it all the time anyway, since the pv_ops backend might want to fiddle with the values on the way through.
I tried to avoid calling init_gdt twice, but it seemed cleaner to just let it happen.
> Getting rid of the call in smp_prepare_boot_cpu currently works, but > it's fragile: __get_cpu_var(x) && per_cpu(x, smp_processor_id()) will > differ, and changes made to __get_cpu_var(x) will vanish... >
Yes. I think its definitely a good idea to call init_gdt asap after doing the percpu setup.
> Fortunately, UP doesn't have to call init_gdt at all, so I think it's > better to place it in smp_prepare_boot_cpu only and then clean up the UP > code. I'll try now... > It doesn't? The per-cpu gdt is the same as the boot gdt?
J - 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/
| |