Date: Tue, 15 Jun 2004 01:10:01 -1000 From: juli mallett <jmallett@FreeBSD.org> To: freebsd-mips@FreeBSD.org Subject: caches and whatnot. Message-ID: <20040615111001.GA48501@FreeBSD.org>
next in thread | raw e-mail | index | archive | help
So I was having some problems getting things to work on real HW so I started looking in some possible problem areas, and sort of glossing over the problem, I got sidetracked by caches. So I decided to try running with caches on the Indigo2 and fix up the TLB abstraction to handle invalidates and whatnot, figuring it'd be pretty easy since 1) I do have the TLB abstraction 2) this is just kernel code. And Lo! An hour later, booting with caches all the way to mountroot> on my real, live Indigo2. So other than the "shiny thing" excuse, what made me do this? Well, I was looking at the emulator (ports/emulators/mips64emul) and the Indigo2 side by side, and started kernels more or less exactly at the same time, starting a little bit later with mips64emul. The emulator booted to mountroot> in about 3 seconds faster than my 250MHz Indigo2! Obscene! So I figured it was a cache issue, so now, with the exact same emulator running the same way... It takes 46 seconds to boot the emulator to mountroot>, and 6 seconds on the Indigo2 running with caches. The emulator doesn't do caches, and even if it did, I'm not sure it could run in tandem with that. Just thought I'd share those data points in case anyone else found them interesting. Unfortunately now I have no excuse to not do devices and whatnot that I've been sort of holding off on, on real hardware ;) Thanx, juli. -- juli mallett. jmallett@freebsd.org. adrift in the pacific.
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20040615111001.GA48501>