# Re: \[PATCH V3 4/5\] mm: mmap: Add mmap flag to request VM\_LOCKONFAULT

- From: Eric B Munson \<hidden\>
- Date: 2015-07-21 15:37:26 
- List: linux-api
- Page: https://ratatoskr.run/linux-api/2015/07/4539845
- Thread: https://ratatoskr.run/linux-mm/2015/07/4529312/t.md

```text
On Mon, 20 Jul 2015, Chris Metcalf wrote:

> On 07/18/2015 03:11 PM, Paul Gortmaker wrote:
> >On Tue, Jul 7, 2015 at 1:03 PM, Eric B Munson[ref]  wrote:
> >>>The cost of faulting in all memory to be locked can be very high when
> >>>working with large mappings.  If only portions of the mapping will be
> >>>used this can incur a high penalty for locking.
> >>>
> >>>Now that we have the new VMA flag for the locked but not present state,
> >>>expose it  as an mmap option like MAP_LOCKED -> VM_LOCKED.
> >An automatic bisection on arch/tile leads to this commit:
> >
> >5a5656f2c9b61c74c15f9ef3fa2e6513b6c237bb is the first bad commit
> >commit 5a5656f2c9b61c74c15f9ef3fa2e6513b6c237bb
> >Author: Eric B Munson[ref]
> >Date:   Thu Jul 16 10:09:22 2015 +1000
> >
> >     mm: mmap: add mmap flag to request VM_LOCKONFAULT
> 
> Eric, I'm happy to help with figuring out the tile issues.

Thanks for the offer, I think I have is sorted in V4 (which I am
checking one last time before I post).

Eric
```

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