Kernel Bug Tracker – Bug 18162
userspace software suspend hangs at "s2disk: Snapshotting system"
Last modified: 2011-03-03 01:33:47 UTC
Created attachment 29442 [details]
hardware of my ThinkPad T42
Last kernel that worked:
- 188.8.131.52-tp42-toi-184.108.40.206-05125-ga817cb9 for sure. Absolutely stable.
- I am not sure whether I tested 2.6.34 with userspace software suspend as with that one those freezes I reported in bug #16376 "random - possibly Radeon DRM KMS related - freezes" appeared.
This is with Nigel'c TuxOnIce tree 2.6.36-rc3 + TOI 3.2-rc1. Rafael, if you have a founded suspicion that this might be related to some TOI change, I can test with Linus tree as well.
Please bear with me when I take my time tough, cause after compiling a kernel for a zillion times for bisecting bug #16376, while having holidays and with that radeon drm/kms kernel that works with TuxOnIce - 2.6.33 did only work stably with userspace software supend - I just want to enjoy that kernel for a while, before rebooting and compiling a whole lot again.
If you have some other debug tips I can try, please let me know. AFAIR there is some test stuff that could be activated via sysfs.
It would be good to know in what time frame exactly it regressed. There's
quite a distance from 2.6.33 to 2.6.36-rc3.
Still, can you try (as root)
# echo devices > /sys/power/pm_test && echo disk > /sys/power/state
with the current Linus' tree and see if that freezes too (if not, it will
return to the command prompt after 5 - 10 seconds)?
I tested with with 220.127.116.11-tp42-vmembase-0, which is a plain vanilla 18.104.22.168 from Greg's stable tree. I forgot to include the vmembase-0 patch to "fix" bug #16376, so its really 100% 22.214.171.124.
It hangs as well. No matter whether I use hibernate - which I normally use, cause I find pm-utils utterly overengineered and error prone, for example when it doesn't let me hibernate when I just upgraded a kernel that I am actually not even used - and hibernate:
martin@shambhala:~> apt-show-versions | egrep "(hibernate|pm-utils)"
hibernate/squeeze uptodate 1.99-1.1
pm-utils/squeeze uptodate 1.3.0-2
I also tried the test thing, but /sys/power/pm_test doesn't exist. Thus I just tried:
echo disk > /sys/power/state
It hangs as well. Before it printed:
PM: Syncing filesystems ... done.
Freezing user space processes ... (elapsed 0.01 seconds) done.
Freezing remaining freezable tasks ... (elapsed 0.01 seconds) done.
PM: Preallocating image memory...
I waited over a minute with nothing apparent happening.
But: It worked once from KDM with hibernate script. So it doesn't seem to work anymore once the KDE Desktop has started and initialized OpenGL composoting. I once tried with full KDE 4.5.1 nepomuk/virtuoso desktop search scan activity. The other time I paused scanning for new files. On both attempts it hung.
So plain result is: With plain 126.96.36.199 userspace software suspend and even the kernel based variant just doesn't work. FWIW TuxOnIce currently doesn't work nicely with 2.6.36-rc3 and 188.8.131.52 as well, thus I just downgraded once again to the last known fully working kernel 184.108.40.206 with userspace software suspend.
And now I don't get how to remove that "NEEDINFO" flag.
TuxOnIce made at least *some* cycles with a started KDE desktop, while userspace software suspend hung on every attempt. TuxOnice shows problems on some resumes instead, so I think thats an different TuxOnIce related issue, thus I chose tuxonice-devel for reporting them.
This appears to be the issue fixed by this commit:
Can you please try to apply it on top of 2.6.35.y and see if it helps?
220.127.116.11-tp42-vmembase-0-pm-avoid-oom-dirty works here. Tried two times, one tim with some applications open - a situation where it sometimes doesn't suspend cause it could not free enough low mem pages, just the same issue I have with TuxOnIce after switching to Radeon KMS. Thanks.
Hopefully Nigel can take some time soon to look into fixing up TuxOnIce. Its just faster and more responsive after a cycle.
Userspace software suspend basically seems to swap out lots of stuff prior to creating the image - it takes about a minute from "returned to userspace" before I can basically use the desktop again:
martin@shambhala:~/Computer/Shambhala/Kernel/2.6.35> free -m
total used free shared buffers cached
Mem: 2024 791 1232 0 56 212
-/+ buffers/cache: 523 1500
Swap: 3906 361 3545
(This is after two cycles with a fresh system which usually doesn't yet swap. KDE + applications can go into swap with 2 GiB, but not with just Kontact and a Konqueror window.)
Anyway, it works and if it continues to do so, I finally have an usable 2.6.35 on my ThinkPad T42. So thanks again.