On 2020/3/25 21:32, Peter Zijlstra wrote:

On Wed, Mar 25, 2020 at 12:49:45PM +0800, Zhenyu Ye wrote:

quoted

Hi Peter,

On 2020/3/24 23:01, Peter Zijlstra wrote:

quoted

On Tue, Mar 24, 2020 at 09:45:28PM +0800, Zhenyu Ye wrote:

quoted

In order to reduce the cost of TLB invalidation, the ARMv8.4 TTL
feature allows TLBs to be issued with a level allowing for quicker
invalidation.  This series provide support for this feature. 

Patch 1 and Patch 2 was provided by Marc on his NV series[1] patches,
which detect the TTL feature and add __tlbi_level interface.

I realy hate how it makes vma->vm_flags more important for tlbi.

Thanks for your review.

The tlbi interfaces only have two parameters: vma and addr. If we
try to not use vma->vm_flags, we may should have to add a parameter
to some of these interfaces(such as flush_tlb_range), which are
common to all architectures.

I'm not sure if this is feasible, because this feature is only
supported by ARM64 currently.

Power (p9-radix) also has level dependent invalidation instructions, so
at the very least you can hook them up as well.

.

Thanks, I will push my next version soon.

Zhenyu
.