Re: [PATCH V2] xfs: introduce CONFIG_XFS_WARN

Chandra Seetharaman
2013-04-25T22:30:10Z

Thanks Dave.

On Fri, 2013-04-26 at 07:44 +1000, Dave Chinner wrote:
> On Thu, Apr 25, 2013 at 09:07:49AM -0500, Chandra Seetharaman wrote:
> > On Thu, 2013-04-25 at 08:58 +1000, Dave Chinner wrote:
> > > On Wed, Apr 24, 2013 at 01:39:52PM -0500, Chandra Seetharaman wrote:
> > > > Hi Dave,
> > > >
> > > > Since this solution is for production environment, would it be valuable
> > > > to have a sysctl variable to allow enabling/disabling XFS_WARN, as
> > > > opposed to needing to recompile the module afresh ?
> > >
> > > The idea is that distros enable it on the debug kernel packages
> > > rather than using CONFIG_XFS_DEBUG=y. Hence if someone has a
> > > problem, they just install the debug kernel and they get all this
> > > additional checking.
> >
> > Thanks for the clarification.
> >
> > I was thinking that CONFIG_XFS_DEBUG would be enabled in the distro's
> > debug kernel and this new option is in addition to that. Hence, my
> > question.
>
> If you are shipping a debug kernel with CONFIG_XFS_DEBUG, then you
> don't want your customers running that debug kernel for very long.
> CONFIG_XFS_DEBUG changes allocation algorithms to improve test
> coverage and this causes accelerated filesystem aging....
>
> CONFIG_XFS_WARN is designed to be used instead of CONFIG_XFS_DEBUG
> in these situations - we get more verbose checking, but without the
> down sides associated with all the algorithmic changes in
> XFS_DEBUG...
>
> > So, with this new config option, CONFIG_XFS_DEBUG will only be used in
> > development environment, correct ?
>
> That's what I has always been intended for.
>
> Cheers,
>
> Dave.