kswapd busy but not swapping
From: Christian Kujau
Date: Tue May 20 2008 - 19:05:38 EST
I noticed that the [kswapd0] thread was eating 3-7% cpu time but no
swapspace has been used yet. This is with a just booted 188.8.131.52 system,
currently with some disk i/o going on.
So I figured that kswapd might not be responsible for "swapping" after
all, although the name suggests it. Grep'ing Documentation/ for kswapd did
not reveal much. Is the paper from Kanoj still valid for 2.6 kernels?
The SGI page referenced in Documentation/kernel-docs.txt is down, but
there's a .txt version on  which tells me:
"When memory runs low, and a process can not find a free page, it wakes
up kswapd, the memory stealer"
So, if I'd run low on memory, kswapd would be active. But I don't see that
# free -m
total used free shared buffers cached
Mem: 2023 1662 360 0 820 315
-/+ buffers/cache: 526 1496
Swap: 1505 0 1505
If you're interested, there are more details at
BOFH excuse #197:
I'm sorry a pentium won't do, you need an SGI to connect with us.
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