On Thursday 26 January 2006 07:27, Robert Watson wrote: > On Thu, 26 Jan 2006, Ceri Davies wrote: > > On Thu, Jan 26, 2006 at 09:57:12AM +0000, Murray Stokely wrote: > >> murray 2006-01-26 09:57:12 UTC > >> > >> FreeBSD doc repository > >> > >> Modified files: > >> en/releases/6.1R todo.sgml > >> Log: > >> Add kbdmux and sysinstall smp kernel install items from the ideas page > >> to the 6.1 Desired Features list. > > > > I think it's a little late to mess with sysinstall to that extent for > > 6.1. Sounds like the kind of thing that could sit in -CURRENT for months, > > but hardly anyone would actually be using it. It seems that the main > > problem with sysinstall is that hardly any of our developers use it. > > > > On to the question: how often does an SMP kernel fail to boot where a UP > > one might work? I remember that this used to be a problem, but if it's > > still "too often", can we have just the bits that probe for an mptable > > (or however we determine that there is more that one processor) in the UP > > kernel without suffering that instability? > > > > What I'm basically asking is how much of the SMP code is really required > > just to detect MP hardware? > > SMP kernels now pretty much universally run on UP systems, thanks to work > John did a couple of years ago. The problem has historically been a > performance once: the overhead of all the atomic instructions to run an SMP > kernel on a UP system is significant. We're working gradually to improve > that, but it's still quite noticeable. There has been talk of run-time > compiling/relinking to use different versions of mutexes (and all that), > but no progress as far as I know. I can't speak to how much information > the loader has/needs to decide if it should auto-load an SMP kernel. A > simpler version of the world says that you have an SMP kernel in > sysinstall, and based on it probing CPUs, it sets the default kernel in the > install to GENERIC or SMP.
Yes, I would very much prefer that the install just use an SMP kernel. Note that on all the non-i386 architectures we just have SMP on in GENERIC if it is supported. -- John Baldwin <[EMAIL PROTECTED]> <>< http://www.FreeBSD.org/~jhb/ "Power Users Use the Power to Serve" = http://www.FreeBSD.org _______________________________________________ [email protected] mailing list http://lists.freebsd.org/mailman/listinfo/cvs-all To unsubscribe, send any mail to "[EMAIL PROTECTED]"
