Jerome Glisse wrote: > On Sun, 2009-04-19 at 18:21 +0200, Thomas Hellström wrote: > >> Jerome Glisse wrote: >> >>> On Sat, 2009-04-18 at 21:06 +0200, Thomas Hellström wrote: >>> >>> >>>> Jerome Glisse wrote: >>>> >>>> >>>>> Hi Thomas >>>>> >>>>> I am getting massive error on x86_64, things like : >>>>> BUG: Bad page map in process gnome-session pte:1f1d1d1d01000000 >>>>> pmd:321a6067 >>>>> keep filling the log until very bad things happen. >>>>> Do you have any idea what might cause that in ttm ? >>>>> My assumption is that ttm vm code is guilty their. >>>>> Note that on x86 exact same code seem to run fine. >>>>> All this with 2.6.29 final. >>>>> >>>>> Cheers, >>>>> Jerome Glisse >>>>> >>>>> >>>>> >>>>> >>>> Hi, Jerome! >>>> >>>> The TTM code may well be guilty here. I haven't tested x86-64 for a >>>> while, but I can probably give it a try on openChrome next week. >>>> >>>> /Thomas >>>> >>>> >>> Okay so i really narrowed it down to asking for WC memory, so my guess >>> is that either my CPU (AMD Athlon(tm) Dual Core Processor 4450e) have >>> PAT issue either TTM PAT/WC code is wrong somehow. I haven't time yet >>> to go deeper with this but i think it worked on an Intel Core2 CPU >>> with x86-64. Also it seems other people doesn't have the issue with >>> WC on x86-64. >>> >>> PS: Sorry for all the noise, the bug didn't always showed up quickly so >>> i had false feeling. I am yet unsure it's fully fixed but so far all my >>> test case which triggered it seems to work fine. >>> >>> Cheers, >>> Jerome >>> >>> >>> >> Jerome, >> I think I missed what the fix was? >> >> Anyway, for PAT-aware kernels the drm git TTM code is always assuming >> PAT is enabled and working. >> For production kernels, the function >> >> pgprot_ttm_x86_wc >> >> should be replaced by an exported version of x86 pgprot_writecombine. >> >> FWIW x86-64 seems to work fine here on a 2.6.27 kernel Athlon-64 >> single-core on openChrome. >> >> /Thomas >> > > > Fix is to not ask for WC memory, i will look at this after i cleanup > all my hack to track down this. > > Cheers, > Jerome > > OK.
If there was an erratum causing PAT not to be enabled on your processor, then definitely that may have cause strange inconsistencies. Thanks, Thomas. ------------------------------------------------------------------------------ Stay on top of everything new and different, both inside and around Java (TM) technology - register by April 22, and save $200 on the JavaOne (SM) conference, June 2-5, 2009, San Francisco. 300 plus technical and hands-on sessions. Register today. Use priority code J9JMT32. http://p.sf.net/sfu/p -- _______________________________________________ Dri-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/dri-devel
