On 06/24/2020 08:10 PM, Alexander Gordeev wrote: > On Wed, Jun 24, 2020 at 01:48:08PM +0200, Gerald Schaefer wrote: >> On Wed, 24 Jun 2020 13:05:39 +0200 >> Alexander Gordeev <agord...@linux.ibm.com> wrote: >> >>> On Wed, Jun 24, 2020 at 08:43:10AM +0530, Anshuman Khandual wrote: >>> >>> [...] >>> >>>> Hello Gerald/Christophe/Vineet, >>>> >>>> It would be really great if you could give this series a quick test >>>> on s390/ppc/arc platforms respectively. Thank you. >>> >>> That worked for me with the default and debug s390 configurations. >>> Would you like to try with some particular options or combinations >>> of the options? >> >> It will be enabled automatically on all archs that set >> ARCH_HAS_DEBUG_VM_PGTABLE, which we do for s390 unconditionally. >> Also, DEBUG_VM has to be set, which we have only in the debug config. >> So only the s390 debug config will have it enabled, you can check >> dmesg for "debug_vm_pgtable" to see when / where it was run, and if it >> triggered any warnings. > > Yes, that is what I did ;) > > I should have been more clear. I wonder whether Anshuman has in > mind other options which possibly makes sense to set or unset > and check how it goes with non-standard configurations. After enabling CONFIG_DEBUG_VM either explicitly or via DEBUG_VM, ideally any memory config combination on s390 which can change platform page table helpers (validated with CONFIG_DEBUG_VM) should also get tested. Recently, there was a kernel crash on ppc64 [1] and a build failure on ppc32 [2] for some particular configs. Hence it will be great if you could run this test on multiple s390 configurations. [1] 787d563b8642f35c5 ("mm/debug_vm_pgtable: fix kernel crash by checking for THP support") [2] 9449c9cb420b249eb ("mm/debug_vm_pgtable: fix build failure with powerpc 8xx") - Anshuman