Re: [ofa-general] Re: [GIT PULL] please pull ummunotify

Roland Dreier
2009-09-15T14:57:56Z

> I don't remember seeing discussion of this on lkml. Yes it is in
> -next...

eg http://lkml.org/lkml/2009/7/31/197 and followups, or search for v2
and earlier patches.

> Basically it allows app to 'trace itself'? ...with interesting mmap()
> interface, exporting int to userspace, hoping it behaves atomically...?

Yes, it allows app to trace what the kernel does to memory mappings. I
don't believe there's any real issue to atomicity of mmap'ed memory,
since userspace really just tests whether read value is == to old read
value or not.

- R.