Re: [RFC PATCH 2/7] mm/vmalloc: Track which page-table levels were modified

Joerg Roedel
2020-05-08T21:23:27Z

On Fri, May 08, 2020 at 09:10:48PM +0200, Peter Zijlstra wrote:
> On Fri, May 08, 2020 at 04:40:38PM +0200, Joerg Roedel wrote:
> > + if (mask & ARCH_PAGE_TABLE_SYNC_MASK)
> > + arch_sync_kernel_mappings(start, end);
>
> So you're relying on the compiler DCE'ing the call in the 'normal' case.
>
> Works I suppose, but I went over the patches twice to look for a default
> implementation of it before I figured that out ...

Yes, works on all architectures I compile-tested this on, with gcc-9.3.
I should probably add a comment about that.

Joerg