System behaved as if OOM when it had plenty to spare
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
linux (Ubuntu) |
Expired
|
Medium
|
Unassigned |
Bug Description
Had the weirdest behaviour today, current karmic kernel. I haven't got a swap partition or swap file configured, because I was playing with swapd and stuff earlier and hadn't turned them back on again.
The system suddenly became extremely slow and unresponsive, with massive amounts of disk activity
The thing is, here was the output of free at the time:
total used free shared buffers cached
Mem: 1534944 1490160 44784 0 18396 1078164
-/+ buffers/cache: 393600 1141344
Swap: 0 0 0
In other words, while it had actually 44MB free (which is still quite a lot, even though I was doing things in Firefox) - there was 1GB of cached pages sitting there - and I was doing much so most of them can't have been dirty!
So why was the machine even touching the disk? It should have been able to simply purge non-dirty pages from its cache and carry on
Or am I grossly missing something?
Changed in linux (Ubuntu): | |
importance: | Undecided → Medium |
status: | New → Triaged |
Plot thickens a bit... looks like even the OOM killer got involved
is there any way to debug why the kernel was so keen on keeping that 1GB of page cache around that it killed other things instead?