Re: [RFC PATCH v2 0/6] kcov: per-task dataflow extraction at kernel function boundaries

Peter Zijlstra <[email protected]> Fri, 12 Jun 2026 09:38:58 +0200

Newsgroups	org.kernel.vger.workflows,dev.linux.lists.llvm,org.kernel.vger.linux-doc,org.kernel.vger.linux-kbuild,org.kernel.vger.linux-kernel,org.kernel.vger.rust-for-linux
Message-ID	<[email protected]>

On Fri, Jun 12, 2026 at 09:37:40AM +0200, Yunseong Kim wrote:
> Hi Peter,
> 
> > On Wed, Jun 03, 2026 at 07:43:27PM +0200, Yunseong Kim wrote:
> >> CONFIG_KCOV_DATAFLOW_INSTRUMENT_ALL instruments every function in the
> >> kernel. 
> > 
> > Well, I would hope it would very much not instrument noinstr functions.
> 
> Thank you for your guidance. I updated the default
> CONFIG_KCOV_DATAFLOW_NO_INLINE to n.

That's not really the point. The compiler extension *must* respect
noinstr. If there it no function attribute to suppress this kcov stuff,
then its an absolute non-starter.