Re: something really screwed up with mmap+ffs on 5.0_STABLE

[Antti Kantee <pooka%cs.hut.fi@localhost>]

On Wed Sep 01 2010 at 15:23:42 +0200, Thomas Klausner wrote:
> On Tue, Aug 17, 2010 at 11:52:31PM +0300, Antti Kantee wrote:
> > It would be great if someone could confirm or debunk this on -current
> > and for archs beyond i386.  Just get the latest sources, go to
> > sys/rump/net/lib/libshmif, comment out line 61 (the one with PREFAULT_RW)
> > from if_shmif.c, "make && make install", and run tests/net/icmp/t_ping
> > floodping in a loop.  You should see a coredump within a few thousand
> > iteratios (few minutes) if the problem is there.
> 
> I think you mean if_shmem.c.

Something like that with a fuzzy match.

> I just tested this on 5.99.39/amd64.
> # ./t_ping floodping
> got 0/10000
> passed
> # while true; do ./t_ping floodping; done
> panic: kernel diagnostic assertion "busmem->shm_magic == SHMIF_MAGIC" failed: 
> file "if_shmem.c", line 287
> panic: kernel diagnostic assertion "busmem->shm_magic == SHMIF_MAGIC" failed: 
> file "if_shmem.c", line 287

Thanks.  This has been analyzed and fixed by chuq already.  He said he
just needs more time to verify the fix is correct.  It's essentially
kern/40389, but it turns out the hack I wrote to get 5.0 out wasn't
quite complete.  What goes around comes around ...