Re: [PATCH v2 3/4] sparc64: remove mm_cpumask clearing to fix kthread_use_mm race
From: David Miller
Date: Mon Sep 14 2020 - 15:59:57 EST
From: Nicholas Piggin <npiggin@xxxxxxxxx>
Date: Mon, 14 Sep 2020 14:52:18 +1000
...
> The basic fix for sparc64 is to remove its mm_cpumask clearing code. The
> optimisation could be effectively restored by sending IPIs to mm_cpumask
> members and having them remove themselves from mm_cpumask. This is more
> tricky so I leave it as an exercise for someone with a sparc64 SMP.
> powerpc has a (currently similarly broken) example.
>
> Signed-off-by: Nicholas Piggin <npiggin@xxxxxxxxx>
Sad to see this optimization go away, but what can I do:
Acked-by: David S. Miller <davem@xxxxxxxxxxxxx>