Re: [PATCH 01/25] xor: assert that xor_blocks is not called from interrupt context

Christoph Hellwig <[email protected]> Wed, 4 Mar 2026 16:42:41 +0100

Newsgroups	org.kernel.vger.sparclinux,dev.linux.lists.loongarch,org.infradead.lists.linux-riscv,org.infradead.lists.linux-um,org.kernel.vger.linux-alpha,org.kernel.vger.linux-arch,org.kernel.vger.linux-btrfs,org.kernel.vger.linux-crypto,org.kernel.vger.linux-kernel,org.kernel.vger.linux-raid,org.kernel.vger.linux-s390,org.ozlabs.lists.linuxppc-dev
Message-ID	<[email protected]>

On Wed, Mar 04, 2026 at 04:15:48PM +0100, Peter Zijlstra wrote:
> On Wed, Mar 04, 2026 at 03:51:34PM +0100, Christoph Hellwig wrote:
> 
> > > How about "WARN_ON_ONCE(!preemptible())"?  I think that covers the union
> > > of the context restrictions correctly.  (Compared to in_task(), it
> > > handles the cases where hardirqs or softirqs are disabled.)
> > 
> > Good enough I guess.  Peter?
> 
> Sure. The only caveat with that is that for PREEMPT_COUNT=n this might
> not work, it unconditionally returns 0.

That's a pretty good argument for the lockdep version...