Re: [Qemu-devel] Help on TLB Flush

[Alexander Graf]

On 12.02.15 15:58, Peter Maydell wrote:
> On 12 February 2015 at 14:45, Alexander Graf <address@hidden> wrote:
>> almost nobody except x86 does global flushes
> 
> All ARM TLB maintenance operations have both "this CPU only"
> and "all TLBs in the Inner Shareable domain" [that's ARM-speak
> for "every CPU core in the cluster"] variants (the latter
> being the TLB *IS operations). Looking at Linux's
> arch/arm64/mm/tlb.S and arch/arm64/include/asm/tlbflush.h
> most of the operations defined there use the IS variants.

Wow, did anyone benchmark this? I know that PPC switched away from
global flushes and instead tracks the CPUs a task was running on to
limit the scope of CPUs that need to flush.


Alex