Re: icache_is_aliasing and big.LITTLE
From: Salman Qazi
Date: Thu May 09 2019 - 14:15:35 EST
On Thu, May 9, 2019 at 1:50 AM Catalin Marinas <catalin.marinas@xxxxxxx> wrote:
> On Wed, May 08, 2019 at 11:45:03AM -0700, Salman Qazi wrote:
> > What is the intention behind icache_is_aliasing on big.LITTLE systems
> > where some icaches are VIPT and others are PIPT? Is it meant to be
> > conservative in some sense or should it be made per-CPU?
> It needs to cover the worst case scenario across all CPUs, i.e. aliasing
> VIPT if one of the CPUs has this. We can't make it per-CPU because a
> thread performing cache maintenance might be migrated to another CPU
> with different cache policy (e.g. sync_icache_aliases()).