Re: [PATCH 1/2] mm/slub: Add panic function when slub leaks

[zhang fangzheng]

On Wed, Sep 25, 2024 at 4:10 PM Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> wrote:
>
> On Wed, Sep 25, 2024 at 11:22:55AM +0800, Fangzheng Zhang wrote:
> > Perform real-time memory usage monitoring on the slub page
> > allocation paths, ie, kmalloc_large_alloced and alloc_slab_page.
> > When the usage exceeds the set threshole value, the panic function
> > will be triggered.
> >
> > Signed-off-by: Fangzheng Zhang <fangzheng.zhang@xxxxxxxxxx>
> > ---
> >  mm/Kconfig | 11 ++++++++
> >  mm/slub.c  | 76 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
> >  2 files changed, 87 insertions(+)
> >
> > diff --git a/mm/Kconfig b/mm/Kconfig
> > index 09aebca1cae3..60cf72d4f0da 100644
> > --- a/mm/Kconfig
> > +++ b/mm/Kconfig
> > @@ -255,6 +255,17 @@ config SLUB_TINY
> >
> >          If unsure, say N.
> >
> > +config SLUB_LEAK_PANIC
> > +     bool "Trigger panic when slub leaks"
> > +     default y
>
> "default y" is only there if the feature is required to boot the machine
> properly.  That's not the case here, sorry.
>
> thanks,
>
> greg k-h

Hi Greg,

The reason why the "default y" is set here is that config is only valid for
the functional code that works. To truly implement slub_leak_panic, the
parameters must be set effectively. And, the current parameters are all
in the default n.

Thanks.