On Fri, Sep 09, 2011 at 10:38:16PM +0200, roberth wrote: > Hi, > > got around to upgrade my Thinkpad X200 (amd64) to 8GB RAM from 2GB. > Since then after resume from sleep X is very laggy. > Not just talking about apps that were open before the sleep/resume > cycle, but also newly started. > > After rebooting the system every thing is dandy. > > Anyone? > Ideas where to start investigating? > > - Robert >
This is a known issue with MTRRs on that model and a few others. The MTRRs are not being reprogrammed properly on resume, and the result is a large range of memory resuming as non-cacheable. It is on the radar to be fixed (a few of us have looked at this but no fix has come yet). Here's what I did: 1. memconfig list - note the non-bios memory ranges at the end of the list 2. make yourself a script that you can run as root after resume. Mine looks like this: memconfig set -b 0x0 -l 0x80000000 write-back memconfig set -b 0x80000000 -l 0x40000000 write-back memconfig set -b 0x100000000 -l 0x100000000 write-back memconfig set -b 0x200000000 -l 0x40000000 write-back You'll need to get the base and length values from step 1. Basically, you're just resetting the cacheability bits to whatever 'memconfig list' says they should be. This will probably be fixed at some point, but for now, it's not. -ml
