On Fri, Oct 12, 2018 at 11:18:36AM -0700, David Miller wrote: > From: Joel Fernandes <joel@xxxxxxxxxxxxxxxxx> [...] > > Also, do we not flush the caches from any path when we munmap > > address space? We do call do_munmap on the old mapping from mremap > > after moving to the new one. > > Sparc makes sure that shared mapping have consistent colors. Therefore > all that's left are private mappings and those will be initialized by > block stores to clear the page out or similar. > > Also, when creating new mappings, we flush the D-cache when necessary > in update_mmu_cache(). > > We also maintain a bit in the page struct to track when a page which > was potentially written to on one cpu ends up mapped into another > address space and flush as necessary. > > The cache is write-through, which simplifies the preconditions we have > to maintain. Makes sense, thanks. For the moment I sent patches to enable this on arm64 and x86. We can enable it on sparc as well at a later time as it sounds it could be a safe optimization to apply to that architecture as well. thanks, - Joel
