On Tue, Oct 13, 2020 at 12:25:44PM +0100, Christoph Hellwig wrote: > > - kaddr = kmap(pp); > > + kaddr = kmap_thread(pp); > > memcpy(kaddr, vip->vii_immed.vi_immed + offset, PAGE_SIZE); > > - kunmap(pp); > > + kunmap_thread(pp); > > You only Cced me on this particular patch, which means I have absolutely > no idea what kmap_thread and kunmap_thread actually do, and thus can't > provide an informed review. Sorry the list was so big I struggled with who to CC and on which patches. > > That being said I think your life would be a lot easier if you add > helpers for the above code sequence and its counterpart that copies > to a potential hughmem page first, as that hides the implementation > details from most users. Matthew Wilcox and Al Viro have suggested similar ideas. https://lore.kernel.org/lkml/20201013205012.GI2046448@xxxxxxxxxxxxxxxxxxxxxxxxx/ Ira