Re: [Patch v3] mm/memblock: remove empty dummy entry

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

On 6/20/24 18:07, Wei Yang wrote:
> On Thu, Jun 20, 2024 at 02:58:17PM -0700, Guenter Roeck wrote:
>> Hi,
>>
>> On Fri, Apr 05, 2024 at 01:58:21AM +0000, Wei Yang wrote:
>>> The dummy entry is introduced in the initial implementation of lmb in
>>> commit 7c8c6b9776fb ("powerpc: Merge lmb.c and make MM initialization
>>> use it.").
>>>
>>> As the comment says the empty dummy entry is to simplify the code.
>>>
>>> 	/* Create a dummy zero size LMB which will get coalesced away later.
>>>           * This simplifies the lmb_add() code below...
>>>           */
>>>
>>> While current code is reimplemented by Tejun in commit 784656f9c680
>>> ("memblock: Reimplement memblock_add_region()"). This empty dummy entry
>>> seems not benefit the code any more.
>>>
>>> Let's remove it.
>>>
>>> Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
>>> CC: Paul Mackerras <paulus@ozlabs.org>
>>> CC: Tejun Heo <tj@kernel.org>
>>> CC: Mike Rapoport <rppt@kernel.org>
>>>
>>
>> With this patch in linux-next, all microblaze qemu images fail to boot. Reverting it
>> fixes the problem.
>>
>> Bisect log is attached for reference.
>>
> 
> Thanks for the reporting.
> 
> Would you mind running the test to take a look?
> 
> It is in tools/testing/memblock. Simply make and ./main.
> 

This is a silent failure. There is no console output, so the image crashes
before it gets to that point.

Building microblaze:petalogix-s3adsp1800:initrd ... running ................R............. failed (silent)
------------
qemu log:
qemu-system-microblaze: terminating on signal 15 from pid 2343410 (/bin/bash)

Guenter