[ltt-dev] Unable to boot linux-2.6.34 kernel patched with patch-2.6.34-lttng-0.218 on CentOS 5.5 distro

[Rashawn Knapp]

Hi Folks,

 

I am new to this mailing list and I am working on my first build of LTTng
kernel tracer.   I have encountered a couple of obstacles, and I am not sure
what I should try next.  I am running Centos 5.5 with kernel
2.6.18-194.8.1.el5.  I have downloaded linux-2.6.34 from kernel.org and the
patch set for LTTng 0.218 (patch-2.6.34-lttng-0.218) that is compatible with
the 2.6.34 kernel.

 

I patched the vanilla kernel using Quilt.

I then configured the kernel, starting with the configuration file of the
kernel I was currently working in (the CentOS 2.6.18-194.8.1.el5
configuration).

I used make menuconfig to select LTTng options, based on instructions given
in the LTTng users' guide.  Upon inspection of the saved .config file, I
have the following LTT configuration:

CONFIG_TRACEPOINTS=y

CONFIG_MARKERS=y

...

CONFIG_LTT=y

CONFIG_LTT_FILTER=m

CONFIG_HAVE_LTT_DUMP_TABLES=y

CONFIG_LTT_TRACER=m

CONFIG_LTT_RELAY_LOCKLESS=y

# CONFIG_LTT_RELAY_IRQOFF is not set

# CONFIG_LTT_RELAY_LOCKED is not set

CONFIG_LTT_SERIALIZE=m

CONFIG_LTT_FAST_SERIALIZE=m

CONFIG_LTT_TRACEPROBES=m

CONFIG_LTT_TRACE_CONTROL=m

CONFIG_LTT_ALIGNMENT=y/

CONFIG_LTT_CHECK_ARCH_EFFICIENT_UNALIGNED_ACCESS=y

# CONFIG_LTT_DEBUG_EVENT_SIZE is not set

CONFIG_LTT_USERSPACE_EVENT=m

CONFIG_LTT_VMCORE=y

CONFIG_LTT_STATEDUMP=m

CONFIG_LTT_KPROBES=m

# CONFIG_LTT_ASCII is not set

CONFIG_HAVE_IMMEDIATE=y

CONFIG_IMMEDIATE=y

 

 

I then did the following to build and install the kernel:

make

make modules_install

make install

 

This all seemed to work - no errors. 

 

I rebooted into the new kernel, and I encountered the following errors:

1. insmod: error inserting '/lib/dm-region-hash.ko': -1 File exists

2.            Volume group "VolGroupp00" not found

                 mount: could not find filesystem 'dev/root'

                .

                ..

                kernel panic

 

Some googling helped me find the cause of error 1.  The init script in the
initrd image tries to load the module twice.  This error goes away by
unpacking the initrd image, removing the second attempt, and then repacking
the image and overwriting the old image with the new one.

 

The googling also helped me find a possible solution to the second error:
configure CONFIG_SYSFS_DEPRECATED_V2=y in the kernel.

 

OK, so I tried that; after recompiling the kernel,  the Volumes are now
found and the file systems mount.  After mounting the files systems, I see
this new error: "Cannot access the Hardware Clock via any known method".
The kernel does not appear to finish booting:  I don't see the usual list of
things scroll by.  Instead I see output similar to this, and I eventually
restart the machine (these blocks continue to repeat, with different values
in the code section):

Stack:

Call Trace:

<IRQ>

<EOI>

Code: 79 27 02 00 ...

 

 

I then tried a build and install of just the vanilla linux-2.6.34 kernel (no
lttng patches applied).  With the vanilla build, I had to make the fix to
the initrd image and I had to configure the kernel with
CONFIG_SYSFS_DEPRECATED_V2=y to get it to boot completely.  I still see the
error about the Hardware Clock, but the kernel finishes booting and I get a
login prompt.

 

My question is what should I do to get the machine to boot an lttng patched
kernel?  At this point, I am not sure what to try next (different
distribution?, different kernel config settings?, other stuff?).   I would
also be curious to know what distributions and vanilla kernel with lttng
patch set combinations are working for folks.  I looked at the mail archive
for the past couple of months, but I did not see something that addressed
this issue.  If there is an older thread that discusses this, please point
me to it.

 

Thank you,

 

Rashawn

 

 

 

 

 

 

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