On Wed, 5 Jan 2005, Andrew Morton wrote:
Rik van Riel <riel@xxxxxxxxxx> wrote:
The recent OOM kill problem has been happening:
1) with cache pressure on lowmem only, due to a block device write
2) with no block congestion at all
3) with pretty much all pageable lowmme pages in writeback state
You must have a wild number of requests configured in the queue. Is this CFQ?
Yes, it is with CFQ. Around 650MB of lowmem is in writeback
stage, which is over 99% of the active and inactive lowmem
pages...
I've done testing with "all of memory under writeback" before and it went OK. It's certainly a design objective to handle this well. But that testing was before we broke it.
I suspect something might still be broken. It may take a few
days of continuous testing to trigger the bug, though ...