Re: 2.5.46: kernel BUG at kernel/timer.c:333!

[Miquel van Smoorenburg]

According to Andrew Morton:
> Miquel van Smoorenburg wrote:
> > 
> > I've booted 2.5.46bk5 on the machine, and it has been running for over
> > 2 hours with extra heavy diskio. That reliably crashed the machine
> > in about 45 minutes with 2.4.45 and 2.5.46, machine is still up now.
> 
> OK, thanks.

It survived the night and is still up. Looks like it runs slightly
faster than 2.4.20-X.

> This is a blockdev which was under mmap(), yes?  No, I haven't looked at
> that yet.  It'll be a matter of just killing the warning.

OK.

> mmapping a blockdev is a pretty dopey thing to do, btw.  It doesn't
> allow the use of highmem, the IO uses tiny BIOs (in fact I think
> it uses 512-byte or 1k blocksize too) and there are buffer_heads
> all over the place.  You'll get better results from mmapping a
> regular file.

It's just that the news server uses its own 'filesystem'. It does
normal read/write i/o on it, but the allocation bitmap at the
beginning of the 'file' is mmap()ed. Using a regular file means
creating a 160 GB file, the triple indirect blocks will probably
kill performance.

I guess that means I have to resurrect rawfs, then (a filesystem
I wrote for 2.2 that shows partitions as fixed-size files). But
that seems so .. unnecessary.

Mike.