On Wed, 25 Sep 2013 06:48:04 -0700 "Paul E. McKenney" <paul...@linux.vnet.ibm.com> wrote:
> On Tue, Sep 24, 2013 at 09:10:47PM -0700, Andrew Morton wrote: > > On Tue, 24 Sep 2013 18:29:11 -0700 "Paul E. McKenney" > > <paul...@linux.vnet.ibm.com> wrote: > > > > > --- a/mm/mlock.c > > > +++ b/mm/mlock.c > > > @@ -736,6 +736,7 @@ static int do_mlockall(int flags) > > > > > > /* Ignore errors */ > > > mlock_fixup(vma, &prev, vma->vm_start, vma->vm_end, newflags); > > > + cond_resched(); > > > } > > > out: > > > return 0; > > > > Might need one in munlock_vma_pages_range() as well - it's a matter of > > finding the right test case. This will be neverending :( > > Indeed... I suspect that Trinity running on big-memory systems will > eventually find most of them via RCU CPU stall warnings, but as you say... > > Would you like the corresponding change to munlock_vma_pages_range() > beforehand? Can't decide. If we went and poked holes in every place which looks like it loops for a long time, we'd be poking holes everywhere, some of them unnecessary. otoh if we wait around for people to say "hey" then it will take a very long time to poke all the needed holes. The best approach would be for someone to sit down, identify all the potential problem spots, attempt to craft a userspace exploit to verify that each one really is a problem, then fix it. Nobody will bother doing this. So I dunno. Stop asking difficult questions ;) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
