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Subject: Re: ppc elf_map breakage with MAP_FIXED_NOREPLACE
To:     Michal Hocko <mhocko@kernel.org>,
        Anshuman Khandual <khandual@linux.vnet.ibm.com>
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Cc:     Michael Ellerman <mpe@ellerman.id.au>, akpm@linux-foundation.org,
        mm-commits@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-mm@kvack.org, linux-fsdevel@vger.kernel.org,
        linux-next@vger.kernel.org, sfr@canb.auug.org.au,
        broonie@kernel.org
From:   Anshuman Khandual <khandual@linux.vnet.ibm.com>
Date:   Tue, 23 Jan 2018 16:55:18 +0530
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On 01/17/2018 01:37 PM, Michal Hocko wrote:
> On Thu 11-01-18 15:38:37, Anshuman Khandual wrote:
>> On 01/09/2018 09:43 PM, Michal Hocko wrote:
> [...]
>>> Did you manage to catch _who_ is requesting that anonymous mapping? Do
>>> you need a help with the debugging patch?
>>
>> Not yet, will get back on this.
> 
> ping?

Hey Michal,

Missed this thread, my apologies. This problem is happening only with
certain binaries like 'sed', 'tmux', 'hostname', 'pkg-config' etc. As
you had mentioned before the map request collision is happening on
[10030000, 10040000] and [10030000, 10040000] ranges only which is
just a single PAGE_SIZE. You asked previously that who might have
requested the anon mapping which is already present in there ? Would
not that be the same process itself ? I am bit confused. Would it be
helpful to trap all the mmap() requests from any of the binaries
and see where we might have created that anon mapping ?