Created attachment 115841 [details] dmesg Since I am using Dracut, my system stucks the most time on boot, shortly after extracting the initramfs. Sometimes the notebook is able to boot, but mostly it stucks. So I need 5 - 10 tries to make my Linux run. After enabling the dracut debug functions, it seems to be a udev problem: [4.359394] systemd-udevd[1147]: error reading /etc/udev/hwdb.bin: No such file or directory This causes a Null Pointer Exception: [0.770990] BUG: unable to handle kernel NULL pointer dereference at (null) The file (hwdb.bin) becomes available later in boot process. I am not 100% sure if this is the real reason for the boot problem, but i guess it is. (I am not the only one who has this problem - http://forums.gentoo.org/viewtopic-t-934308-highlight-.html) I attach my dmesg output including the dracut debug messages.
It seems like this is the same bug: https://bugs.gentoo.org/show_bug.cgi?id=462928
Just to add/summarize some information: - I am also using Gentoo Linux, but with the pure (vanilla) kernel sources. - I tried out different kernel, dracut and udev versions (also "eudev") - but the problem always persists - According to the discussion in the Gentoo Bugzilla, my assumption is probably wrong and the missing "hwdb.bin" file is not the reason for the problem - maybe this is just a side effect - The Gentoo developer Tom Wijsman presumes: "This happens in match_futex where one of the parameters given to it is null. This call is made from kernel/futex.c:2154, where I assume this->key to be the problematic parameter as the other parameter is set properly at the start of that function. This apparently comes from a list of waiters. One of the waiters to be problematic, not sure how to know which one."
I have solved the problem on my Gentoo system by replacing (e)udev with systemd.