Bug 12464
Summary: | PAT: duplicated lines in /sys/kernel/debug/x86/pat_memtype_list | ||
---|---|---|---|
Product: | Platform Specific/Hardware | Reporter: | Frans Pop (elendil) |
Component: | x86-64 | Assignee: | platform_x86_64 (platform_x86_64) |
Status: | CLOSED INVALID | ||
Severity: | low | CC: | suresh.b.siddha, venki, yinghai |
Priority: | P1 | ||
Hardware: | All | ||
OS: | Linux | ||
Kernel Version: | 2.6.28 | Subsystem: | |
Regression: | --- | Bisected commit-id: | |
Attachments: |
Contents of /sys/kernel/debug/x86/pat_memtype_list (after X.Org crash)
Contents of /proc/mtrr (does not change) Full X.Org log Kernel config |
Description
Frans Pop
2009-01-17 03:09:05 UTC
Created attachment 19846 [details]
Contents of /sys/kernel/debug/x86/pat_memtype_list (after X.Org crash)
Created attachment 19847 [details]
Contents of /proc/mtrr (does not change)
Created attachment 19848 [details]
Full X.Org log
Created attachment 19850 [details]
Kernel config
Reassigned to x86_64. Is this a regression? Was any previous kernel OK? I don't have any data for previous kernel versions, so I cannot say if it is a regression or not. I could try .27 if I find a reliable way to reproduce. I've now found a way to reproduce this and the good news is that it is unrelated to PAT: I can also reproduce it after booting with 'nopat'. The way to reproduce it is: - boot with laptop docked - log in to KDE and activate dual display with: xrandr --output VGA --left-of LVDS --mode 1280x1024 - disable the laptop display: xrandr --output LVDS --off - undock the laptop, which results in: xrandr --output LVDS --auto --output VGA --off - start VirtualBox virtual machine If I dock the laptop again before starting VirtualBox, the X.Org crash does not happen. It also does not happen if the laptop display is enabled before I undock it. Also, the display corruption on VT1 only happens after the X.Org crash, not if I switch consoles before starting VirtualBox. The added line in pat_memtype_list looks to be unrelated, and is even somewhat "normal". Even after I have just booted my laptop (with KDE running and dual-display active), I see a number of duplicate lines in that file: # cat /sys/kernel/debug/x86/pat_memtype_list | sort | uniq -c 1 PAT memtype list: 1 uncached-minus @ 0x7e7b0000-0x7e7b1000 1 uncached-minus @ 0x7e7c4000-0x7e7c5000 1 uncached-minus @ 0x7e7c5000-0x7e7c7000 1 uncached-minus @ 0x7e7c5000-0x7e7c8000 !! 7 uncached-minus @ 0x7e7c8000-0x7e7c9000 1 uncached-minus @ 0x7e7c8000-0x7e7dc000 1 uncached-minus @ 0x7e7db000-0x7e7dc000 !! 3 uncached-minus @ 0x7e7dc000-0x7e7dd000 !! 2 uncached-minus @ 0x7e7e7000-0x7e7e8000 1 uncached-minus @ 0x7e7e9000-0x7e7ea000 1 uncached-minus @ 0x88000000-0x88001000 1 uncached-minus @ 0xd0000000-0xd0020000 1 uncached-minus @ 0xd0000000-0xd0300000 1 uncached-minus @ 0xd0000000-0xe0000000 1 uncached-minus @ 0xe0000000-0xe0002000 1 uncached-minus @ 0xe0100000-0xe0101000 1 uncached-minus @ 0xe0101000-0xe0102000 1 uncached-minus @ 0xe0102000-0xe0103000 !! 3 uncached-minus @ 0xe0400000-0xe0480000 1 uncached-minus @ 0xe0400000-0xe0500000 !! 2 uncached-minus @ 0xe0480000-0xe0500000 1 uncached-minus @ 0xe0620000-0xe0640000 1 uncached-minus @ 0xe0640000-0xe0641000 1 uncached-minus @ 0xe0641000-0xe0642000 1 uncached-minus @ 0xe0644000-0xe0648000 1 uncached-minus @ 0xe0648000-0xe0649000 1 uncached-minus @ 0xf8000000-0xfc000000 1 uncached-minus @ 0xfed00000-0xfed01000 !! 2 uncached-minus @ 0xfed93000-0xfed94000 The first time I undock and redock the laptop just adds one extra duplicate line. Is this something that should be looked into? I've just tested this with 2.6.26.3 and with that kernel I can also reproduce the X.Org crash, so it is definitely not a recent kernel regression. I have also found that the X.Org crash does not happen if after undocking I first enable the laptop display and only then disable the external monitor. So if instead of: xrandr --output LVDS --auto --output VGA --off I do: xrandr --output LVDS --auto xrandr --output VGA --off Looks to me like this is an X.Org issue, and not a kernel bug. So if the duplicated lines in pat_memtype_list are not an issue, this BR can be closed. Duplicate lines in pat_memtype_list doesn't really indicate an issue. It just indicates that more than one user has mapped that address range with the corresponding attribute. OK, let's close it then. JFTR, the X.Org issue is now: http://bugs.freedesktop.org/show_bug.cgi?id=19643 |