[PATCH 1/1] ARM: thumb: Have the machine name indicate operation in thumb mode.

On Wed, 18 May 2011, Russell King - ARM Linux wrote:

On Wed, May 18, 2011 at 06:27:56PM -0400, Nicolas Pitre wrote:

quoted

On Wed, 18 May 2011, Vadim Bendebury (??) wrote:

quoted

On Mon, May 16, 2011 at 7:43 AM, Dave Martin [off-list ref] wrote:

quoted

On Mon, May 16, 2011 at 10:32:16AM -0400, Nicolas Pitre wrote:

quoted

I think this can be useful to know how the kernel was compiled for bug
tracking purposes, just like we record the Git commit ID of the checked
out source tree, the gcc version, the build date, etc. ?Which pretty
much indicates that the thumbness of the kernel should probably be
stored in the kernel banner not the platform name.

That seems a reasonable approach to me.

guys, thank you for your comments. Indeed, this is meant to be just a
convenience to allow to quickly tell what kind of kernel a system is
running, comes handy when there are many systems around with
differently compiled kernels.

So, would it be acceptable if I move this information into the kernel
banner (namely, add it to the machine hardware name part of the output
included in 'uname -m' and 'uname -a')?

Yes, I think that would be the most sensible place.  Looking at 
scripts/mkcompile_h which is used to create include/generated/compile.h, 
it appears that $CONFIG_FLAGS would be the most appropriate place for 
this, however it is not currently set up to allow architecture specific 
flags to be passed in.

We already have a way of adding stuff for bug tracking purposes.  The
"Internal error" line is perpended with 'PREEMPT' or 'SMP' depending
on what build options were enabled.  We just need to do the same with
T2.  IOW, something like this:

[...]

This is indeed useful if the kernel oopses.  However this doesn't help 
for those cases where the kernel doesn't crash but still exhibits 
unexpected behaviors.  Having the thumbness of the kernel also displayed 
in dmesg and uname -a would also be good to have.


Nicolas