Good Day,

My laptop has had terrible battery life since upgrading to Slackware 14.2 64 bit from 14.1/32.

According to top, kswapd0 is using 90-100% CPU, see below, any ideas on how to troubleshoot this condition?

Thanks.

<pre style='color:#1f1c1b;background-color:#ffffff;'>
top - 11:56:52 up 17:23, 2 users, load average: 1.58, 1.24, 1.12
Tasks: 175 total, 2 running, 173 sleeping, 0 stopped, 0 zombie
%Cpu(s): 12.3 us, 63.7 sy, 0.1 ni, 23.5 id, 0.1 wa, 0.0 hi, 0.4 si, 0.0 st
KiB Mem : 1671936 total, 477448 free, 515376 used, 679112 buff/cache
KiB Swap: 20971516 total, 20820224 free, 151292 used. 826740 avail Mem

PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
47 root 20 0 0 0 0 R 94.1 0.0 213:39.49 kswapd0
1 root 20 0 4372 664 632 S 0.0 0.0 0:00.57 init
2 root 20 0 0 0 0 S 0.0 0.0 0:00.00 kthreadd
3 root 20 0 0 0 0 S 0.0 0.0 0:00.45 ksoftirqd/0
5 root 0 -20 0 0 0 S 0.0 0.0 0:00.00 kworker/0:+
7 root 20 0 0 0 0 S 0.0 0.0 1:13.82 rcu_sched
8 root 20 0 0 0 0 S 0.0 0.0 0:00.00 rcu_bh
9 root rt 0 0 0 0 S 0.0 0.0 0:00.01 migration/0
10 root rt 0 0 0 0 S 0.0 0.0 0:00.01 migration/1
11 root 20 0 0 0 0 S 0.0 0.0 0:00.12 ksoftirqd/1
13 root 0 -20 0 0 0 S 0.0 0.0 0:00.00 kworker/1:+
14 root 20 0 0 0 0 S 0.0 0.0 0:00.00 kdevtmpfs
15 root 0 -20 0 0 0 S 0.0 0.0 0:00.00 netns
</pre>

Hello,

I found this thread and this kernel bug report about this issue.


As stated in this post you can try to workaround this by running the command below :
If this does not work, you can also try this workaround.

--
SeB

Either you have no swap partition or it's not created/formatted correctly.

zk1234,

I tried:

swapoff /dev/sda2

mkswap /dev/sda2 with no errors and

swapon /dev/sda2

kswapd0 is still running full steam ahead.

phenixia2013,

The drop_caches setteing does not work. I will have to try the other cure next.

Just in case, here are the results of a free command after reformatting the swap partition:

total used free shared buff/cache available
Mem: 1671936 1176192 148088 253008 347656 79216
Swap: 20971516 0 20971516


and I am running the stock 64 bit kernel vmlinuz-generic-4.4.14 as shipped with slackware.

After reading through the link about other workarounds, I decided to try passing "mem=1920M" as an argument to the kernel since I also have a laptop with 2048M of memory. So far this seems to be working.