Re: X server being killed a lot

[Michael <macallan%netbsd.org@localhost>]

Hello,

On Mon, 22 Oct 2018 07:34:37 +0200
Thomas Klausner <tk%giga.or.at@localhost> wrote:

> On Fri, Aug 17, 2018 at 08:20:35AM +0200, Thomas Klausner wrote:
> > On Sat, Jul 28, 2018 at 06:44:50PM +0900, Izumi Tsutsui wrote:  
> > > > When I'm running a bulk build, the X server is a likely victim.
> > > > 
> > > > UVM: pid 28091.1 (X), uid 0 killed: out of swap
> > > > 
> > > > I'm not really sure why because I have lots of swap.
> > > > 
> > > > Swap: 148G Total, 27G Used, 121G Free  
> > > 
> > > I also see the similar problem, on NetBSD/i386 8.0 with 8GB swap.
> > > 
> > > Jul 22 09:29:25 mirage /netbsd: UVM: pid 75.1 (Xorg), uid 0 killed: out of swap
> > > Jul 22 22:43:04 mirage /netbsd: UVM: pid 75.1 (Xorg), uid 0 killed: out of swap
> > > Jul 22 22:48:24 mirage /netbsd: UVM: pid 4999.1 (Xorg), uid 0 killed: out of swap
> > > Jul 22 22:50:08 mirage /netbsd: UVM: pid 14199.1 (Xorg), uid 0 killed: out of swap
> > > Jul 22 22:58:48 mirage /netbsd: UVM: pid 3339.1 (Xorg), uid 0 killed: out of swap
> > > Jul 22 23:09:28 mirage /netbsd: UVM: pid 11407.1 (Xorg), uid 0 killed: out of swap
> > > Jul 22 23:12:20 mirage /netbsd: UVM: pid 29705.1 (Xorg), uid 0 killed: out of swap
> > > Jul 22 23:21:39 mirage /netbsd: UVM: pid 1100.1 (Xorg), uid 0 killed: out of swap
> > > 
> > > It seems easily reproducible by running firefox and makefs(8)
> > > to create learge iso/ffs images.  
> > 
> > Does anyone have any insight in this?
> > 
> > This is highly annoying behaviour for me - it happens even when I'm
> > actively using the X session, so it's definitely not because it's the
> > least-used process in the system.  
> 
> It just happened again for me.
> 
> top says:
> 
> CPU states:  0.2% user,  0.0% nice, 15.4% system, 17.4% interrupt, 66.8% idle
> Memory: 14G Act, 6984M Inact, 10M Wired, 1758M Exec, 18G File, 59M Free
> Swap: 148G Total, 148G Free
> 
> so there is some pressure on the I/O system for file data, but no swap
> use.
> 
> It looks to me like the priority of the File section is too high, if X
> is killed for that...

Possibly related:
I've had firefox starting to get swapped out ( and everything slowing
to a crawl because of it ) while in active use, with more than half of
RAM being used as file cache, and nothing hammering the filesystem
either.
One would think the OS would shrink the cache first, especially if it's
several gigabytes.

It helped somewhat to add this to sysctl.conf:
vm.filemin=2
vm.filemax=10
now it still uses well over 10% or memory as file cache but seems more
willing to shrink it.

have fun
Michael