Re: [PATCH 15/24] x86/mm: Allow flushing for future ASID switches

From: Peter Zijlstra
Date: Thu Nov 30 2017 - 10:44:48 EST


On Mon, Nov 27, 2017 at 11:49:14AM +0100, Ingo Molnar wrote:
> @@ -338,24 +366,23 @@ static inline void __native_flush_tlb_single(unsigned long addr)
>
> static inline void __flush_tlb_all(void)
> {
> + if (boot_cpu_has(X86_FEATURE_PGE)) {
> __flush_tlb_global();
> + } else {
> __flush_tlb();
> + tlb_flush_shared_nonglobals();

I do however think this one is superfluous; if we do not have PGE we
also do not have PCID and every CR3 switch flushes everything.

> + }
> }