Re: [PATCH 0/18] change mmap_sem taken for write killable

From: Michal Hocko
Date: Mon Feb 29 2016 - 09:16:36 EST


On Mon 29-02-16 17:04:16, Kirill A. Shutemov wrote:
[...]
> > Most of the patches are really trivial because the lock is help from a
> > shallow syscall paths where we can return EINTR trivially. Others seem
> > to be easy as well as the callers are already handling fatal errors and
> > bail and return to userspace which should be sufficient to handle the
> > failure gracefully. I am not familiar with all those code paths so a
> > deeper review is really appreciated.
>
> What about effect on userspace? IIUC, we would have now EINTR returned
> from bunch of syscall, which haven't had this errno on the table before.
> Should we care?

Those function will return EINTR only when the current was _killed_ when
we do not return to the userspace. So there shouldn't be any visible
effect.
--
Michal Hocko
SUSE Labs