Re: [PATCH] arch/{mips,sparc,microblaze,powerpc}: Don't enable pagefault/preempt twice

[Guenter Roeck <linux@roeck-us.net>]

On 5/19/20 10:13 PM, Ira Weiny wrote:
> On Tue, May 19, 2020 at 12:42:15PM -0700, Guenter Roeck wrote:
>> On Tue, May 19, 2020 at 11:40:32AM -0700, Ira Weiny wrote:
>>> On Tue, May 19, 2020 at 09:54:22AM -0700, Guenter Roeck wrote:
>>>> On Mon, May 18, 2020 at 11:48:43AM -0700, ira.weiny@intel.com wrote:
>>>>> From: Ira Weiny <ira.weiny@intel.com>
>>>>>
>>>>> The kunmap_atomic clean up failed to remove one set of pagefault/preempt
>>>>> enables when vaddr is not in the fixmap.
>>>>>
>>>>> Fixes: bee2128a09e6 ("arch/kunmap_atomic: consolidate duplicate code")
>>>>> Signed-off-by: Ira Weiny <ira.weiny@intel.com>
>>>>
>>>> microblazeel works with this patch,
>>>
>>> Awesome...  Andrew in my rush yesterday I should have put a reported by on the
>>> patch for Guenter as well.
>>>
>>> Sorry about that Guenter,
>>
>> No worries.
>>
>>> Ira
>>>
>>>> as do the nosmp sparc32 boot tests,
>>>> but sparc32 boot tests with SMP enabled still fail with lots of messages
>>>> such as:
>>>>
>>>> BUG: Bad page state in process swapper/0  pfn:006a1
>>>> page:f0933420 refcount:0 mapcount:1 mapping:(ptrval) index:0x1
>>>> flags: 0x0()
>>>> raw: 00000000 00000100 00000122 00000000 00000001 00000000 00000000 00000000
>>>> page dumped because: nonzero mapcount
>>>> Modules linked in:
>>>> CPU: 0 PID: 1 Comm: swapper/0 Tainted: G    B             5.7.0-rc6-next-20200518-00002-gb178d2d56f29 #1
>>>> [f00e7ab8 :
>>>> bad_page+0xa8/0x108 ]
>>>> [f00e8b54 :
>>>> free_pcppages_bulk+0x154/0x52c ]
>>>> [f00ea024 :
>>>> free_unref_page+0x54/0x6c ]
>>>> [f00ed864 :
>>>> free_reserved_area+0x58/0xec ]
>>>> [f0527104 :
>>>> kernel_init+0x14/0x110 ]
>>>> [f000b77c :
>>>> ret_from_kernel_thread+0xc/0x38 ]
>>>> [00000000 :
>>>> 0x0 ]
>>>>
>>>> Code path leading to that message is different but always the same
>>>> from free_unref_page().
> 
> Actually it occurs to me that the patch consolidating kmap_prot is odd for
> sparc 32 bit...
> 
> Its a long shot but could you try reverting this patch?
> 
> 4ea7d2419e3f kmap: consolidate kmap_prot definitions
> 

That is not easy to revert, unfortunately, due to several follow-up patches.

Guenter

> Alternately I will need to figure out how to run the sparc on qemu here...
> 
> Thanks very much for all the testing though!  :-D
> 
> Ira
> 
>>>>
>>>> Still testing ppc images.
>>>>
>>
>> ppc image tests are passing with this patch.
>>
>> Guenter