On Mon, May 17 2021 at 18:26, Robin Murphy wrote:

On 2021-05-17 17:57, Nitesh Lal wrote:
I'm not implying that there isn't a bug, or that this code ever made 
sense in the first place, just that fixing it will unfortunately be a 
bit more involved than a simple revert. This patch as-is *will* subtly 
break at least the system PMU drivers currently using

s/using/abusing/

irq_set_affinity_hint() - those I know require the IRQ affinity to 
follow whichever CPU the PMU context is bound to, in order to meet perf 
core's assumptions about mutual exclusion.

Which driver is that?

Thanks,

        tglx