Messages in this thread | | | Date | Fri, 16 Jan 2009 14:46:21 +0100 | From | Ingo Molnar <> | Subject | Re: Is 386 processor still supported? |
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* Pavel Machek <pavel@suse.cz> wrote:
> > > > * Maciej W. Rozycki <macro@linux-mips.org> wrote: > > > > > On Thu, 15 Jan 2009, Alan Cox wrote: > > > > > > > > UP emulation of CMPXCHG and XADD for userland should be rather trivial, > > > > > so why not include it like with LL/SC for MIPS? > > > > > > > > Why not just ship an additional libc with the right options ? > > > > > > Does not work for MIPS as glibc has no equivalent code for pre-LL/SC > > > CPUs and LL/SC is always used. For the i386 the situation seems worse > > > yet as for pre-i486 CPUs a generic C implementation of > > > compare-and-exchange is used guaranteeing silent thread unsafety. :( > > > > > > IMO, a kernel emulation of CMPXCHG and XADD (both are used by > > > sysdeps/i386/i486/bits/atomic.h in glibc) with an optional LOCK prefix, > > > guaranteeing UP atomicity would be a cheap way to provide long-term i386 > > > userland support with little burden for both Linux and respective user > > > software maintainers. Certainly it adds some bloat to the kernel, but I > > > think it is not an option that should be outright dismissed without > > > consideration. > > > > patches are welcome ... > > Hehe, I guess the only long-term solution is to get shiny old 386 as a > part of Ingo's test farm ;-).
hehe :) Alas, Thomas has one and occasionally boots the kernel on it.
Ingo
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