System freezes when doing heavy IO in Jaunty with ext4

[Leon Nardella]

I am experiencing frequent lock-ups/hangs/freezes with the Jaunty Desktop Beta version, using ext4.
Every now and then it'll freeze, no matter if I just booted or if I've been logged in for 5 hours.
I have experimented a lot of things to trigger these freezes what I could come up with was:

1- Install Jaunty Desktop Beta
2- Install svn ++ build-essentials
3- Check out llvm's trunk
3- ( Usually in llvm/tools ) Check out clang's trunk
4- ( Usually in llvm/tools ) Check out llvm-gcc' trunk
5- Build it ( ./configure --enable-optimized )
6- Delete llvm's folder ( rm -rf llvm/ )

Although this procedure will take a lot of time, it consistently triggers the freeze on my system.
After de first freeze, it'll sometimes freeze again if you do a 'make clean' in llvm's folder or you try to svn update.

I'd like to reinforce that this is reproducible without installing any other packages or updates (although it will keep on freezing even on a fully updated system).

I checked some logs in /var/logs and couldn't really find anything suspicious.

I'm eager to hear back from you guys and expecting more instructions what I can do to help.

( I'm usually hanging around in #ubuntu and can test whatever is needed )

ProblemType: Bug
Architecture: i386
DistroRelease: Ubuntu 9.04
Lsusb:
 Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
 Bus 005 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
 Bus 004 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
 Bus 003 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
 Bus 002 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
MachineType: Dell Inc. Latitude 120L
Package: linux-image-2.6.28-11-generic 2.6.28-11.37
ProcCmdLine: root=UUID=ee19bc76-4354-4c7a-bebb-ff8f669b79b2 ro quiet splash
ProcEnviron:
 LANG=en_US.UTF-8
 SHELL=/bin/bash
ProcVersionSignature: Ubuntu 2.6.28-11.37-generic
SourcePackage: linux

[Leon Nardella (leon.nardella)]

I forgot to say that when the system freezes, I can't even kill X ( even after installing dontzap and doing 'dontzap --disable' ).

[Leon Nardella (leon.nardella)]

As somebody on #ubuntu-kernel ( I think it was maco ) suggested, I checked out two little things:
1- When the systems freezes, I can't ping it.
2- When I'm reproducing this bug per the instructions in the bug report, the last process (from 'top') is 'rm'.

[Leon Nardella (leon.nardella)]

So... I've been doing some tests and it seems kernel http://kernel.ubuntu.com/~kernel-ppa/mainline/v2.6.29.1/linux-image-2.6.29-02062901-generic_2.6.29-02062901_i386.deb fixes this bug.

I'd greatly appreciate if other people encountering this bug could test that kernel and report how it goes.

[Leon Nardella (leon.nardella)]

So... I was reproducing this again via the root shell from the Ubuntu rescue mode menu and some time after LLVM's compilation starts, I start to see lots of these:

BUG: soft lockup - CPU#0 stuck for 61s [cc1plus3655]

[Leon Nardella (leon.nardella)]

Marking as a duplicate of #330824.