From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: From: jmk@plan9.bell-labs.com To: 9fans@cse.psu.edu Subject: Re: [9fans] acme, rio workalike available in plan 9 ports In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Date: Tue, 20 Apr 2004 13:39:32 -0400 Topicbox-Message-UUID: 63a6460c-eacd-11e9-9e20-41e7f4b1d025 It is flushed entirely at other times (like on a page fault) when it doesn't need to be. The instructions to do that didn't exist on the original 386. On Tue Apr 20 13:35:46 EDT 2004, eli@cs.wisc.edu wrote: > > On Tue, 20 Apr 2004 jmk@plan9.bell-labs.com wrote: > > > > > On Tue Apr 20 11:53:45 EDT 2004, rminnich@lanl.gov wrote: > > > On Tue, 20 Apr 2004, Eli Collins wrote: > > > > > > > Regarding the TLB and SOs, I can't figure out all the fuss either since > > > > the TLB is flushed on context switch (on x86 at least). > > > > > > and that's the problem. > > > > > > ron > > > > Plan 9 on the x86 does not do a very good job of managing the TLB, when > > the port was done there was only the option of flushing it entirely. Better > > code for the modern variants may happen. > > > > Where could it be improved? My understanding is that on x86 the TLB needs > to be flushed entirely on context switch regardless of the OS (unless you > want to carve up the 4GB linear address space among all proceses and use > segmentation registers). >