Date: Sun, 22 Dec 1996 12:24:35 -0500 (EST) From: "John S. Dyson" <toor@dyson.iquest.net> To: phk@freebsd.org Cc: smp@freebsd.org Subject: Re: P6 problem idea Message-ID: <199612221724.MAA07051@dyson.iquest.net> In-Reply-To: <24900.851245819@critter.tfs.com> from "Poul-Henning Kamp" at Dec 22, 96 10:10:19 am
next in thread | previous in thread | raw e-mail | index | archive | help
> > > John Dyson has enabled the "Global" bit on some parts of the kernel. > This makes the marked pages immune to TLB flushes. Could this be the > reason for the P6 Problems ? > > I belive there is a bit in a control register that will enable/disable > this, it's probably in locore.s somewhere. > If you want to test that -- all you have to do is to disable the setting of PG_G in locore and in pmap. You can also optionally turn off the capability (but you still need to disable all of the PG_G bit setting) by not setting the CR4_PGE bit in cr4 also. This *could* be the problem, because you need to do the single page updates when the PG_G bit has been set (or there are more complex ways of doing it also.) The global update will just not work... (Of course, that is much of the purpose of the PG_G bit :-)). John
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?199612221724.MAA07051>