> I ran "iozone -s 4000m" again with a new kernel (your attached patch).
> I'm getting the same errors and have attached a slab.out.gz file showing
> slabinfo every 1s during the test. The __alloc_pages: error shows up a
> few seconds into the test. buffer_head values seem to ramp up
> quickly with iozone...
One more question, are you running on top of md/lvm? I see you have a lot of
disk hardware connected to the box, just wondering if iozone is getting
to access lots of it, or just one device out of all the ones you have.
The fundamental issue appears to be dirtying memory way faster than it can
be cleaned, and not throttling the dirtying of memory correctly. You have
12000 pages worth of buffer heads allocated, which may be a bit excessive!