[plug] 2.4.24 mremap root exploit

[Bernard Blackham]

On Thu, Feb 19, 2004 at 07:38:30AM +0800, Craig Ringer wrote:
> > I'm currently playing with Bonnie++ to see what thrashing the system
> > turns up. As it's running live services, the benchmarks won't be fair,
> > but should be somewhat informative nonetheless.
> 
> *gack*
> 
> I had to abort the Bonnie++ run on the RAID 5 array, because the system
> was crawling to a halt. Load avg >15, ls blocking for 30 seconds, etc.
> Bad stuff.
> 
> Something is clearly not right here. Whether it's LVM2/device-mapper (if
> so, LVM1 had the same problem), the kernel I/O scheduler, the 3ware
> driver, the 3ware card firmware, or something else I do not know.

The anticipatory IO scheduler in 2.6 doesn't like heavy solid I/O
loads at all - it optimises for scattered random accesses. Try
booting the kernel with 'elevator=deadline' on the kernel
commandline and see if it helps.

Bernard.

-- 
 Bernard Blackham <bernard at blackham dot com dot au>