Re: [PATCH] mm/vmalloc: a slight change of compare target in __insert_vmap_area()

[Wei Yang <richard.weiyang@gmail.com>]

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On Fri, May 26, 2017 at 09:55:31AM +0800, zhong jiang wrote:
>On 2017/5/26 9:36, Wei Yang wrote:
>> On Thu, May 25, 2017 at 11:04:44AM +0800, zhong jiang wrote:
>>> I hit the overlap issue, but it  is hard to reproduced. if you think it is safe. and the situation
>>> is not happen. AFAIC, it is no need to add the code.
>>>
>>> if you insist on the point. Maybe VM_WARN_ON is a choice.
>>>
>> Do you have some log to show the overlap happens?
> Hi  wei
>
>cat /proc/vmallocinfo
>0xf1580000-0xf1600000  524288 raw_dump_mem_write+0x10c/0x188 phys=8b901000 ioremap
>0xf1638000-0xf163a000    8192 mcss_pou_queue_init+0xa0/0x13c [mcss] phys=fc614000 ioremap
>0xf528e000-0xf5292000   16384 n_tty_open+0x10/0xd0 pages=3 vmalloc
>0xf5000000-0xf9001000 67112960 devm_ioremap+0x38/0x70 phys=40000000 ioremap

These two ranges overlap.

This is hard to say where is the problem. From the code point of view, I don't
see there is possibility to allocate an overlapped range.

Which version of your kernel?
Hard to reproduce means just see once? 

>0xfe001000-0xfe002000    4096 iotable_init+0x0/0xc phys=20001000 ioremap
>0xfe200000-0xfe201000    4096 iotable_init+0x0/0xc phys=1a000000 ioremap
>0xff100000-0xff101000    4096 iotable_init+0x0/0xc phys=2000a000 ioremap
>
>I hit the above issue, but the log no more useful info. it just is found by accident.
>and it is hard to reprodeced. no more info can be supported for further investigation.
>therefore, it is no idea for me. 
>
>Thanks
>zhongjinag
>

-- 
Wei Yang
Help you, Help me

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