On Thu, Jul 22, 2021, 11:20 PM Michal Hocko <mhocko@xxxxxxxx> wrote:
On Thu 22-07-21 21:47:56, Suren Baghdasaryan wrote:
> On Thu, Jul 22, 2021, 7:04 PM Shakeel Butt <shakeelb@xxxxxxxxxx> wrote:
>
> > On Thu, Jul 22, 2021 at 6:14 PM Suren Baghdasaryan <surenb@xxxxxxxxxx>
> > wrote:
> > >
> > [...]
> > > +
> > > + mmap_read_lock(mm);
> >
> > How about mmap_read_trylock(mm) and return -EAGAIN on failure?
> >
>
> That sounds like a good idea. Thanks! I'll add that in the next respin.
Why is that a good idea? Can you do anything meaningful about the
failure other than immediately retry the syscall and hope for the best?
I was thinking if this syscall implements "best effort without blocking" approach then for a more strict usage user can simply retry. However retrying means issuing another syscall, so additional overhead...
I guess such "best effort" approach would be unusual for a syscall, so maybe we can keep it as it is now and if such "do not block" mode is needed we can use flags to implement it later?
--
Michal Hocko
SUSE Labs
