On Thu, Jan 05, 2017 at 11:13:57AM -0800, Dave Hansen wrote:

On 12/26/2016 05:54 PM, Kirill A. Shutemov wrote:

quoted

MM would use min(RLIMIT_VADDR, TASK_SIZE) as upper limit of virtual
address available to map by userspace.

What happens to existing mappings above the limit when this upper limit
is dropped?

Nothing: we only prevent creating new mappings. All existing are not
affected.

The semantics here the same as with other resource limits.

Similarly, why do we do with an application running with something
incompatible with the larger address space that tries to raise the
limit?  Say, legacy MPX.

It has to know what it does. Yes, it can change limit to the point where
application is unusable. But you can to the same with other limits.

-- 
 Kirill A. Shutemov

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