On Wed, 12 Sep 2012 13:27:10 -0700 Jesse Barnes <jbarnes at virtuousgeek.org> wrote: > This adds a module parameter, gtt_suspend_verify, that will enable a > simple GTT checksum across suspend and resume. > > We currently spend a good amount of time (>20ms) clearing all the GTT > PTEs at resume time, even though this may not be necessary on some > machines. This debug feature is intended to help determine whether > newer machines don't need the unconditional GTT clear on resume. > > Signed-off-by: Jesse Barnes <jbarnes at virtuousgeek.org> It's a cool idea, but I'd vote against adding a module parameter to verify it. Daniel's trees should be well enough tested that you could just disable it on IVB+ or whatever and let it go through QA and developer testing. Aside from that, a debugfs flag to toggle it would probably be a little better. Also, as a bikeshed you could probably get a much better detection with a CRC or something similar. I dunno, just a thought, -- Ben Widawsky, Intel Open Source Technology Center
