Re: [gentoo-user] problems with performance when booted using systemd

["J. Roeleveld" <joost@antarean.org>]

On Friday, June 06, 2014 03:45:17 AM covici@ccs.covici.com wrote:
> J. Roeleveld <joost@antarean.org> wrote:
> > On Friday, June 06, 2014 01:59:18 AM covici@ccs.covici.com wrote:
> > > Hi.  I am having some strange performance problems when booted under
> > > systemd.  These problems happened a little bit under openrc, but are
> > > much more pronounced with systemd.
> > 
> > I don't think it's necessarily systemd itself, just a setting that systemd
> > does differently then openrc. See below for more.
> > 
> > > I am using just virtual consoles, no gui whatsoever at the moment.  I
> > > also use tmux with 4 windows in one of the vcs.  My system is an i7
> > > processor, quod core and 16g of ram and 2g of swap space which appears
> > > not to be used.  I am using uvesafb for the console, so I get 64x160
> > > screens.
> > 
> > Sounds similar to my laptop, except I run KDE and got 16g of swap (for
> > hibernate)
> > 
> > > The first problem is that if I don't press any keystrokes for several
> > > minutes and then want to move to another vc, it takes about 3 or 4
> > > seconds after the alt-left arrow or alt-right arrow command to take
> > > effect.  Even within the same vt, if I don't do anything for several
> > > minutes, it takes several seconds till the keystroke echoes and
> > > something happens.  Once I have done this, things act normally, but its
> > > kind of annoying.
> > 
> > Sounds like a powersave setting. I used to get the same on my old laptop
> > with spinning rust. SSDs tend to "spin-up" a lot quicker.
> > 
> > > Also, my load average seems to always be >1.  I have
> > > looked at top and things seem to be OK, except that my cpu usage is like
> > > this:
> > > Tasks: 934 total,   2 running, 931 sleeping,   0 stopped,   1 zombie
> > > %Cpu(s): 12.5 us,  1.2 sy,  0.0 ni, 86.0 id,  0.2 wa,  0.0 hi,  0.0 si,
> > > 0.0 st
> > > KiB Mem:  16450248 total,  9678656 used,  6771592 free,  1084088 buffers
> > > KiB Swap:  2097148 total,        4 used,  2097144 free.  1147688 cached
> > > Mem
> > > 
> > >   PID USER      PR  NI    VIRT    RES    SHR S  %CPU %MEM     TIME+
> > >   COMMAND
> > >  
> > >  9969 root      20   0     708     16      0 R 100.0  0.0   1549:10 v86d
> > >  
> > >   579 root      30  10       0      0      0 S   9.1  0.0  16:09.93
> > >   speakup
> > > 
> > > 11789 root      20   0   22524   2388   1116 R   0.7  0.0   0:00.03 top
> > > 
> > >     7 root       0 -20       0      0      0 S   0.3  0.0   0:10.41
> > >   
> > >   kworker/u:0H
> > > 
> > > and onward ...
> > > This is an awful lot of tasks, I have never seen so many!
> > 
> > That is a lot, I am currently running KDE, firefox and a citrix remote
> > desktop thing. (oh, and skype and kopete and a few other items)
> > KDE is installed with semantic-desktop, but the nepomuk stuff is disabled
> > in system-settings.
> > I have 200 tasks (yes, nice round figure)
> > 
> > > Anyone have any ideas?  Thanks much.
> > 
> > For the amount of tasks, check that you are not starting too many unneeded
> > services. For the load-average of 1, shouldn't be too much of an issue,
> > had
> > similar in the past with a lot of stuff running and slow disks.
> > 
> > For the freezing, I would suggest checking all the powersave options,
> > especially the ones for the harddrives.
> > Is there anything in the logs when this happens? Eg. check the logs right
> > after the system becomes responsible again, maybe there is a hint there
> > what is causing this.
> 
> Unless systemd is setting some powersave options, I certainly never set
> anything like that, this is a desktop  machine, not even a laptop.  Next
> time this happens I will check the logs.  Does systemd set some
> powersave options by default?

I do not know that for sure, best wait for more knowledgable systemd users to 
answer that. If it doesn't, then systemd itself is causing more freezes (as 
per your experience) then openrc.

I would guess it does or at least with the default configuration. What you 
describe makes me think the disks are switched to powersave sooner with 
systemd.
Can you provide the output of the following command:
#  hdparm -B /dev/sda
to get the APM settings of the disk. (If you have multiple disks, please run 
it for the others as well.

Question for others as well, how do you get the current setting for the 
spindown timeout set with "  hdparm -S <value> <device> "?
I couldn't find it.

I am happy with openrc and have no intention on switching to systemd as I 
haven't heard of a single feature that would actually make my life easier.

--
Joost