[dpdk-dev] [PATCH 2/2] memalloc: keep in mind a failed MAP_FIXED mmap may still perform an unmap

[Burakov, Anatoly]

On 01-Jun-18 1:51 PM, Dariusz Stojaczyk wrote:
> This isn't documented in the manuals, but a failed
> mmap(..., MAP_FIXED) may still unmap overlapping
> regions. In such case, we need to remap these regions
> back into our address space to ensure mem contiguity.
> We do it unconditionally now on mmap failure just to
> be safe.
> 
> Verified on Linux 4.9.0-4-amd64. I was getting
> ENOMEM when trying to map in hugetlbfs with no space
> left, but the previous anonymous mapping was still
> being removed.
> 
> Signed-off-by: Dariusz Stojaczyk <dariuszx.stojaczyk at intel.com>
> ---

Does this also happen with other error values?

-- 
Thanks,
Anatoly