Paul Gofman [off-list ref] writes:

On 5/31/20 20:31, Matthew Wilcox wrote:

quoted

If it's the cost of the syscall that's the problem, there are ways
around that.  We'd still want a personality() call to indicate that
the syscall handler should look (somewhere) to determine the current
personality, but that could be issued at the start of execution rather
than when we switch between Windows & Linux code.

Sure, we can call personality() at start and specify the location to
look at, the only thing is that the location should be thread specific,
that is, based on fs: or gs: or whatever else which would allow us to
have different threads in different "personality" state. If anything
needs to be set up at thread start we can do that also of course.

If there will be any proof of concept solution I will be happy to make a
proof of concept Wine patch using that and do some testing.

Let me give that a try and share the patches with you, so we can look at
how this implementation would look like.

-- 
Gabriel Krisman Bertazi