Re: About the try to remove cross-release feature entirely by Ingo

[Byungchul Park]

On 1/3/2018 5:10 PM, Byungchul Park wrote:
> On 1/3/2018 4:05 PM, Theodore Ts'o wrote:
> > On Wed, Jan 03, 2018 at 11:10:37AM +0900, Byungchul Park wrote:
> > > > The point I was trying to drive home is that "all we have to do is
> > > > just classify everything well or just invalidate the right lock
> > >
> > > Just to be sure, we don't have to invalidate lock objects at all but
> > > a problematic waiter only.
> >
> > So essentially you are proposing that we have to play "whack-a-mole"
> > as we find false positives, and where we may have to put in ad-hoc
> > plumbing to only invalidate "a problematic waiter" when it's
> > problematic --- or to entirely suppress the problematic waiter
>
> If we have too many problematic completions(waiters) to handle it,
> then I agree with you. But so far, only one exits and it seems able
> to be handled even in the future on my own.
>
> Or if you believe that we have a lot of those kind of completions
> making trouble so we cannot handle it, the (4) by Amir would work,
> no? I'm asking because I'm really curious about your opinion..
>
> > altogether. And in that case, a file system developer might be forced
> > to invalidate a lock/"waiter"/"completion" in another subsystem.
>
> As I said, with regard to the invalidation, we don't have to
> consider locks at all. It's enough to invalidate the waiter only.
>
> > I will also remind you that doing this will trigger a checkpatch.pl
> > *error*:
>
> This is what we decided. And I think the decision is reasonable for
> original lockdep. But I wonder if we should apply the same decision
> on waiters. I don't insist but just wonder.

What if we adopt the (4) in which waiters are validated one by one
and no explicit invalidation is involved?

> > ERROR("LOCKDEP", "lockdep_no_validate class is reserved for 
> > device->mutex.\n" . $herecurr);
> >
> > ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ - Ted

--
Thanks,
Byungchul