On Thu, 23 Dec 2010 12:07:22 +0000, Chris Wilson <[email protected]> wrote: > I tweaked the patch to pass the watermark structs through to the check > routine. The box survives s2ram, but I have now also experienced the > mysterious slow down after resuming.
As Eric first said the cause for the slow down is that writing through the GTT becomes very slow: Before suspending: Time to pwrite 16k through the CPU: 0.000004s Time to read 16k through a GTT map: 0.000901s Time to write 16k through a GTT map: 0.000023s Time to read 16k (again) through a GTT map: 0.000900s Time to pwrite 16k through the GTT: 0.000007s After resume: Time to pwrite 16k through the CPU: 0.000004s Time to read 16k through a GTT map: 0.000900s Time to write 16k through a GTT map: 0.000876s Time to read 16k (again) through a GTT map: 0.000899s Time to pwrite 16k through the GTT: 0.000431s The implication being that our mapping goes from write-combining to uncached? -Chris -- Chris Wilson, Intel Open Source Technology Centre _______________________________________________ Intel-gfx mailing list [email protected] http://lists.freedesktop.org/mailman/listinfo/intel-gfx
