Followup to: <Pine.LNX.4.33.0203081532550.4421-100000@penguin.transmeta.com>
By author: Linus Torvalds <torvalds@transmeta.com>
In newsgroup: linux.dev.kernel
>
> You don't understand. This has nothing to do with lock holders, or
> anything else.
>
> I'm saying that we map in a page at a magic offset (just above the stack),
> and that page contains the locking code.
>
> For 386 CPU's (where only UP matters), we can trivially come up with a
> lock that doesn't use cmpxchg8b and that isn't SMP-safe. It might even go
> into the kernel every time if it has to - ie it _works_, it just isn't
> optimal.
>
Okay, I'll say it and be impopular...
Perhaps it's time to drop i386 support?
It seems to me that the i386 support has been around mostly on a
"until we have a reason to do otherwise" basis, but perhaps this is
the reason?
There certainly are enough little, nagging reasons... CMPXCHG, BSWAP,
and especially WP...
-hpa
-- <hpa@transmeta.com> at work, <hpa@zytor.com> in private! "Unix gives you enough rope to shoot yourself in the foot." http://www.zytor.com/~hpa/puzzle.txt <amsp@zytor.com> - 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 : Fri Mar 15 2002 - 22:00:11 EST