Messages in this thread | | | Date | Mon, 19 Oct 2009 00:52:35 +0200 | From | Pavel Machek <> | Subject | Re: [rp] Userspace RCU 0.2.3 |
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On Sun 2009-10-18 18:02:43, Mathieu Desnoyers wrote: > * Pavel Machek (pavel@ucw.cz) wrote: > > On Thu 2009-10-15 13:40:54, Pierre-Marc Fournier wrote: > > > Josh Triplett wrote: > > > > > > > > Even Debian has given up on real 386 systems at this point, primarily > > > > because system libraries like glibc have; 486 and better represents the > > > > bare minimum required at this point. I don't know of any distributions > > > > supporting real 386 systems at this point, and doing so would represent > > > > a major undertaking. > > > > > > > > > > What about embedded systems? Anyone know if some 386 chips, perhaps even > > > in smp configurations, are still in use in those? > > > > smp 386: definitely not. > > Hrm, so for UP 386, I wonder what's the best approach. > > One would be to encapsulate all write accesses to the RCU pointers. If > we detect that the architecture lacks cmpxchg, _all_ update operations > (rcu_assign_pointer, rcu_xchg_pointer and rcu_cmpxchg_pointer) would > have to use the signal-disabled+mutex fall-back. > > Does it make sense ?
Yep, but it sounds expensive. Another option is to ignore the issue and see how many people still have 386s :-). Few embedded systems may be affected, but...
Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
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