F21 Debug Kernels

Adam Williamson adamwill at fedoraproject.org
Fri Jul 11 21:51:28 UTC 2014

On Fri, 2014-07-11 at 12:51 -0400, Shawn Starr wrote:
> On July 11, 2014 08:39:55 AM Mike Chambers wrote:
> > I forget, but isn't there a parameter to turn off debugging on kernels
> > if so desired?  Maint F21, not rawhide (cause I know about the rawhide
> > debug kernels).
> > 
> > 
> > Yes the one I have (that came installed on F21) does have it on.
> I seem to use slub_debug=- which removed all SLUB memory debugging which was 
> quite taxing.

Note that only pre-rc1 kernel builds have the slub debugging stuff
turned on. Builds of rc1 and later have it turned off. This is a
compromise from the kernel team for the issue of slub debugging being
incredibly slow. You can just keep slub_debug=- in your kernel
parameters for all kernels, it'll never break anything, but most of the
time it won't be doing anything.

You can't turn kernel debugging off entirely at runtime; if the kernel
has slub debugging enabled then turning it off will make things
noticeably faster, but a slub debugging kernel with slub debugging
turned off or a 'regular' debugging kernel will still be noticeably
slower than a release kernel.
Adam Williamson
Fedora QA Community Monkey
IRC: adamw | Twitter: AdamW_Fedora | XMPP: adamw AT happyassassin . net

More information about the test mailing list