Thanks... as hoped, it was very interesting... At least one of the corruptions starts at the very end of stolen memory, pagetable entry 1982.
pagetable entry 1981, value 0x87ffbd001 pagetable entry 1982, value 0x87ffbe001 <-------- Last physical page in the stolen address range? (Also mapped to 35654 other pages!) pagetable entry 1983, value 0x82fe5a001 Interstingly, the page of RAM mapped by that entry is repeated in MANY other mappings, as a scratch page to avoid crashing if a write were made to some invalid page in the page table. That page also crops up for some reason in the "middle" of stolen ram: pagetable entry 1536, value 0x87fe00001 pagetable entry 1537, value 0x87ffbe001 <--------- Why is this here?? pagetable entry 1538, value 0x87fe02001 (NB, I don't think its a coincidence that the other page address where I calculated corruption was seen was 1536.??). This is NOT the case in my page table, where the above entries are contiguous, and the last stolen page of ram is NOT used as the scratch page. Next debugging steps... figure out if this is a BIOS bug, or an AGP driver bug messing up the page table. -- screen artifacts after resume, part row of pixels in error (945GM) https://bugs.launchpad.net/bugs/91966 You received this bug notification because you are a member of Ubuntu Bugs, which is the bug contact for Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs