What's up with the swapping since 10/stable

[Mike Jakubik]

Hello,

I just wanted to mention that i have also observed this behavior. Since 
i updated from 9 to 10 my swap usage has increased dramatically, but 
workload has remained the same. This is my desktop pc at work, about a 
day or two after a reboot swap will be around 50% in use.

FreeBSD 10.0-STABLE #0 r263513

Mem: 789M Active, 3842M Inact, 1003M Wired, 115M Cache, 820M Buf, 2156M Free
Swap: 1024M Total, 450M Used, 574M Free, 43% Inuse

Thanks.

On 04/04/14 04:09, Steven Hartland wrote:
> We've noticed that swapping is much more agressive in 10.0 than
> in 8.3 and have indeed seen it swap processes out when there is
> 10GB+ free memory.
>
>    Regards
>    Steve
> ----- Original Message ----- From: "Johan Broman" <johan at bridgenet.se>
> To: "stable-list freebsd" <freebsd-stable at freebsd.org>
> Cc: "Matthias Gamsjager" <mgamsjager at gmail.com>
> Sent: Thursday, April 03, 2014 8:32 PM
> Subject: Re: What's up with the swapping since 10/stable
>
>
> Hi!
>
> I’m seeing the same thing since upgrading to 10/stable. Things seems 
> to need swap although there is still available memory. I tend not to 
> use swap on my virtual instances but I’ve seen error messages like 
> this since upgrading to 10/stable:
>
> pid 3028 (mysqld), uid 88, was killed: out of swap space
>
> Mem: 24M Active, 8012K Inact, 109M Wired, 2176K Cache, 69M Buf, 433M Free
>
>
> Looks like there should be enough memory to start mysql… (the above 
> instance is a t1.micro FreeBSD AMI running on AWS EC2, created by 
> Colin Percival)
>
> Something seems to have changed since FreeBSD 9 in terms of memory 
> manager / page eviction.
>
> Anyone else seeing this? Is it now impossible to run FreeBSD without a 
> swap partition (and or file)? This happens on my server as well which 
> has 8GB RAM and plenty of free RAM…
>
> I don’t want to start guessing, but perhaps this happens when there is 
> some memory fragmentation…? I need to verify if this is the case though.
>
> Thanks
> Johan
>