Anshuman Khandual <khand...@linux.vnet.ibm.com> writes: > On 06/14/2017 12:12 AM, Naveen N. Rao wrote: >> On P9, trying to use data breakpoints throws the splat shown below (*). >> This is because the check for a data breakpoint in DSISR is in >> do_hash_page(). Move this check to handle_page_fault() so as to catch >> data breakpoints in both hash and radix MMU modes. > > Why cant we check for DSISR inside do_hash_page() on P9 ?
We can. But we also need to check inside handle_page_fault(), because when we're in Radix mode we don't go via do_hash_page(). So rather than doing it in two places, the patch changes the logic so we check in handle_page_fault(), and teaches the do_hash_page() code to go there if DSISR_DABRMATCH is set. cheers
