Re: [PATCH] mm: kill kmemcheck

On 03/11/2015 10:26 AM, Steven Rostedt wrote:

quoted

There's no real hurry to kill kmemcheck right now, but we do want to stop

quoted

supporting that in favour of KASan.

Understood, but the kernel is suppose to support older compilers.
Perhaps we can keep kmemcheck for now and say it's obsoleted if you
have a newer compiler. Because it will be a while before I upgrade my
compilers. I don't upgrade unless I have a good reason to do so. Not
sure KASan fulfills that requirement.

It's not that there's a performance overhead with kmemcheck, it's the
maintenance effort that we want to get rid of.

The kernel should keep supporting old kernels, and after this kmemcheck
removal your kernel will still keep working - this is more of a removal
of a mostly unused feature that had hooks everywhere in the kernel.

Did you actually find anything recently with kmemcheck? How do you deal
with the 1 CPU limit and the massive performance hit?

Could you try KASan for your use case and see if it potentially uncovers
anything new?


Thanks,
Sasha