On Mon, Jan 16, 2017 at 12:27:55PM +0000, Yao Qi wrote:

On 17-01-12 11:26:06, Dave Martin wrote:

quoted

Currently the vector length is inherited across both fork() and
exec().

Inheritance across fork() is desirable both for creating a copy of
a process (traditional fork) or creating a thread (where we want
all threads to share the same VL by default).

Inheritance across exec() is less desirable, because of the ABI
impact of large vector lengths on the size of the signal frame --
when running a new binary, there is no guarantee that the new
binary is compatible with these ABI changes.

This flag makes the vector length non-inherited by default.

Can we make vector length inherited across fork but non-inherited
across exec by default?

That is the behaviour: I always inherit across fork/clone, since
you are still running the same binary after those.

I could word the commit message a bit more clearly here.

Cheers
---Dave