On Thu, 16 Sep 2021 16:52:09 +0200, Christophe Leroy wrote:

dcbz instruction shouldn't be used on non-cached memory. Using
it on non-cached memory can result in alignment exception and
implies a heavy handling.

Instead of silentely emulating the instruction and resulting in high
performance degradation, warn whenever an alignment exception is
taken in kernel mode due to dcbz, so that the user is made aware that
dcbz instruction has been used unexpectedly by the kernel.

[...]

Applied to powerpc/next.

[1/1] powerpc: warn on emulation of dcbz instruction in kernel mode
      https://git.kernel.org/powerpc/c/cbe654c779616807e1e6823c3bdbfe07a10562b8

cheers