Re: 4.19.5 and later has tons of false messages "BUG: non-zero pgtables_bytes on freeing mm: -16384"

Sasha Levin
2018-12-27T21:01:36Z

On Thu, Dec 27, 2018 at 10:28:56AM +0100, Christian Borntraeger wrote:
>
>
>On 27.12.2018 10:13, Christian Borntraeger wrote:
>> Martin,
>>
>> Right now you get a message
>> "BUG: non-zero pgtables_bytes on freeing mm: -16384"
>> for EVERY process that exits in 4.19.5 and later.
>>
>> bisect points to
>> commit 4136161d676a93fc8df6bdb80d720c15522d6c24
>> Author: Martin Schwidefsky <schwidefsky@de.ibm.com>
>> Date: Mon Oct 15 11:09:16 2018 +0200
>>
>> s390/mm: fix mis-accounting of pgtable_bytes
>>
>> [ Upstream commit e12e4044aede97974f2222eb7f0ed726a5179a32 ]
>>
>> Turns out that this patch requires several dependencies so the autoselection of this
>> patch was missing that.
>>
>> Can we either revert this patch or add the dependencies?
>>
>> Christian
>>
>
>It seems that adding
>
>commit 6d212db11947ae5464e4717536ed9faf61c01e86 ("mm: add mm_pxd_folded checks to pgtable_bytes accounting functions")
>fixes the issue.

I've queued 6d212db11947 for 4.19 for now, thank you.

--
Thanks,
Sasha