[PATCH v4 00/13] mm/debug_vm_pgtable fixes

[Aneesh Kumar K.V]

On 10/14/20 2:28 AM, Andrew Morton wrote:
> On Wed,  2 Sep 2020 17:12:09 +0530 "Aneesh Kumar K.V" <aneesh.kumar at linux.ibm.com> wrote:
> 
>> This patch series includes fixes for debug_vm_pgtable test code so that
>> they follow page table updates rules correctly. The first two patches introduce
>> changes w.r.t ppc64. The patches are included in this series for completeness. We can
>> merge them via ppc64 tree if required.
> 
> Do you think this series is ready to be merged?

Hopefully, except for the Riscv crash.

> 
> Possibly-unresolved issues which I have recorded are
> 
> Against
> mm-debug_vm_pgtable-locks-move-non-page-table-modifying-test-together.patch:
> 
> https://lkml.kernel.org/r/56830efb-887e-0000-a46e-ae015e5854cd@arm.com

I guess the full series do boot fine on arm.

> https://lkml.kernel.org/r/20200910075752.GC26874@shao2-debian

This should be fixed by

https://ozlabs.org/~akpm/mmots/broken-out/mm-debug_vm_pgtable-avoid-doing-memory-allocation-with-pgtable_t-mapped.patch

> 
> Against mm-debug_vm_pgtable-avoid-none-pte-in-pte_clear_test.patch:
> 
> https://lkml.kernel.org/r/87zh5wx51b.fsf@linux.ibm.com


yes this one we should get fixed. I was hoping someone familiar with 
Riscv pte updates rules would pitch in. IIUC we need to update 
RANDON_ORVALUE similar to how we updated it for s390 and ppc64.


  Alternatively we can do this

modified   mm/debug_vm_pgtable.c
@@ -548,7 +548,7 @@ static void __init pte_clear_tests(struct mm_struct 
*mm, pte_t *ptep,
  	pte_t pte = pfn_pte(pfn, prot);

  	pr_debug("Validating PTE clear\n");
-	pte = __pte(pte_val(pte) | RANDOM_ORVALUE);
+//	pte = __pte(pte_val(pte) | RANDOM_ORVALUE);
  	set_pte_at(mm, vaddr, ptep, pte);
  	barrier();
  	pte_clear(mm, vaddr, ptep);

till we get that feedback from RiscV team?

> https://lkml.kernel.org/r/37a9facc-ca36-290f-3748-16c4a7a778fa@arm.com

same as the above.

> https://lkml.kernel.org/r/20201011200258.GA91021@roeck-us.net
> 

same as the above.

-aneesh