Ubuntu
linux-source-2.6.22 package

nanosleep never returns

Bug #131230 reported by Kees Cook
2
Affects Status Importance Assigned to Milestone
linux-source-2.6.22 (Ubuntu)
Invalid
Undecided
Kees Cook

Bug Description

Binary package hint: initramfs-tools

The "sleep 0.1" in /usr/share/initramfs-tools/scripts/local never returns. (As a result, my delayed root filesystem is never noticed.) An alt-sysrq-F to kill the sleep causes the boot to finish.

Testing during a "break=mount", this hang is 100% reproduceable on my amd64 machine. Even when rebuilding the initramfs with both the regular "sleep" and a recompiled klibc-utils sleep all show the same behavior of a hanging nanosleep. After bootup is finish, nanosleep behaves normally. (!?)

Revision history for this message
Brian Murray (brian-murray) wrote :

I have been unable to reproduce this using kernel version 2.6.22-9. What version of the kernel are you running?

Changed in initramfs-tools:
assignee: nobody → brian-murray
status: New → Incomplete
Revision history for this message
Kees Cook (kees) wrote :

This is with Ubuntu 2.6.22-9.25-generic but has likely been a problem for this machine since 2.6.22-8 at least (prior to this, the md/lvm situation caused the system to be unbootable, so I never hit the "sleep" before...). I cannot reproduce it under (single CPU) i386 or amd64 in vmware. I'm going to try booting single CPU locally to see if it has any impact.

Revision history for this message
Kees Cook (kees) wrote :

I've gathered additional details here: http://outflux.net/nanosleep/

Tried clocksource=tsc without success

Looks like getnstimeofday() is hanging. (?!)

Revision history for this message
Kees Cook (kees) wrote :

nolapic_timer didn't help. Attached output of dmesg, where I stopped at "break=mount" and ran "sleep 1 &" (pid 2741) which was gone after I finished booting.

Revision history for this message
Kees Cook (kees) wrote :

hpet-disable didn't fix it, nolapic didn't fix it, but acpi=off did. clocksource=jiffies didn't fix it.

On a recommendation from the folk on #powertop, I update the BIOS and that fixed it too. /me bangs head on desk

Changed in linux-source-2.6.22:
assignee: brian-murray → keescook
status: Incomplete → Invalid
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