Re: [patch] take 2 Re: PG_swap_entry bug in recent kernels

Kanoj Sarcar
2000-04-09T00:40:45Z

>
> On Sat, 8 Apr 2000, Kanoj Sarcar wrote:
>
> >As I mentioned before, have you stress tested this to make sure grabbing
>
> I have stress tested the whole thing (also a few minutes ago to check the
> latest patch) but it never locked up so we have to think about it.

Okay good.

>
> Could you explain why you think it's the inverse lock ordering?

Let me see, if I can come up with something, I will let you know. If
it survives stress testing, it probably is not inverse locking.

Btw, I am looking at your patch with message id
<Pine.LNX.4.21.0004081924010.317-100000@alpha.random>, that does not
seem to be holding vmlist/pagetable lock in the swapdelete code (at
least at first blush). That was partly why I wanted to know what fixes
are in your patch ...

Note: I prefer being able to hold mmap_sem in the swapdelete path, that
will provide protection against fork/exit races too. I will try to port
over my version of the patch, and list the problems it fixes ...

Kanoj