On Wed, Sep 04, 2019 at 07:19:33AM +0200, Christoph Hellwig wrote: > On Tue, Sep 03, 2019 at 01:53:12PM -0700, Matthew Wilcox wrote: > > > Its enabled in all full debug session as far as I know. Fedora for > > > example has been running this for ages to find breakage in device drivers > > > etc etc. > > > > Are you telling me nobody uses the ramdisk driver on fedora? Because > > that's one of the affected drivers. > > For pmem/brd misaligned memory alone doesn't seem to be the problem. > Misaligned memory that cross a page barrier is. And at least XFS > before my log recovery changes only used kmalloc for smaller than > page size allocation, so this case probably didn't hit. BTW, does sl[aou]b guarantee that smaller than page size allocation via kmalloc() won't cross page boundary any time? Thanks, Ming
