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