|Summary:||userspace software suspend hangs at "s2disk: Snapshotting system"|
|Product:||Power Management||Reporter:||Martin Steigerwald (Martin)|
|Kernel Version:||2.6.36-rc3 and 126.96.36.199||Tree:||Mainline|
|Bug Depends on:|
|Attachments:||hardware of my ThinkPad T42|
Description Martin Steigerwald 2010-09-09 12:04:35 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.
Comment 1 Rafael J. Wysocki 2010-09-09 20:46:17 UTC
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)?
Comment 2 Martin Steigerwald 2010-09-14 12:40:38 UTC
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.
Comment 3 Martin Steigerwald 2010-09-14 13:19:49 UTC
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.
Comment 4 Rafael J. Wysocki 2010-09-14 18:12:27 UTC
This appears to be the issue fixed by this commit: http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=6715045ddc7472a22be5e49d4047d2d89b391f45 Can you please try to apply it on top of 2.6.35.y and see if it helps?
Comment 5 Martin Steigerwald 2010-09-15 09:31:23 UTC
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.