Re: FreeBSD is very slow when Memory chip sizes are imbalanced in slots

On Mon, Mar 18, 2013 at 6:26 AM, Nathan Whitehorn <nwhitehorn_at_freebsd.org>wrote:

> On 03/18/13 07:18, Mehmet Erol Sanliturk wrote:
> > On Mon, Mar 18, 2013 at 4:54 AM, Poul-Henning Kamp <phk_at_phk.freebsd.dk
> >wrote:
> >
> >> In message <CAFHbX1KkD7fWP+KZNrSjzCStUM_Smjw7GdKDTo=
> >> DjjMoe5ttGA_at_mail.gmail.com>, Tom Evans writes:
> >>
> >>> You say this, have you actually measured/checked. sysutils/dmidecode
> >>> will interrogate your BIOS and tell us what it thinks is installed in
> >>> each RAM socket. It is not uncommon for RAM to say one thing on the
> >>> outside, and report something completely different to the BIOS.
> >>
> >> I can only second Tom's call for a proper scientific approach to
> >> debugging this issue, rather than just assume that it is the
> >> operating systems fault.
> >>
> >> --
> >> Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
> >> phk_at_FreeBSD.ORG         | TCP/IP since RFC 956
> >> FreeBSD committer       | BSD since 4.3-tahoe
> >> Never attribute to malice what can adequately be explained by
> incompetence.
> >>
> >
> >
> > I am a graduate of Operations Research and Statistics option of a
> > Mathematics department .
> > All of your considerations are considered . It is so much apparent that ,
> > the cause is FreeBSD .
> >
> > In my previous year message and in its subsequent messages , there are
> > sufficiently detailed information .
> >
> >
> > This message is caused from the following fact :
> >
> > In previous year case , KDE used was a cause , but FluxBox was working
> fast
> > .
> > Now , I have installed 10.0 current . It does not have KDE in packages .
> I
> > have installed FluxBox .
> > It is not a few second slow : Many minutes to start Firefox , and
> activate
> > a menu of it  !
> >
> > What is the point of measuring milliseconds when the difference is around
> > many minutes ?
> >
> > PC-BSD installation ( it is a graphical installation after starting X )
> is
> > taking many hours to reach 20 percent completion .
> > The same is for GhostBSD : Start it at night , at the next morning , it
> is
> > likely that it is not finished yet .
> >
> >
> > Then : WQhat will be measured ?
> >
> > Linux installations are around 30 minutes .
> > Starting/Opening menus are instantenous : I do no have chronometer , but
> > everything is within a second .
> >
> >
> > Thank you very much .
>
> The problem is that "slow" doesn't mean anything. An incomplete list of
> things it might be related to:
> 1. Something to do with the way KDE is built (options, system compiler)
> 2. A disk I/O issue
> 3. A memory speed issue
> 4. Some other process using CPU that isn't running on Linux
> 5. A scheduler issue triggered by some property of the machine
>
> Doing some of these smaller tests will help pin down which of these are
> causing the problem. Without that, there's no possibility to even start
> debugging. Even just running top and seeing whether you are spinning in
> a user thread, in the kernel, or waiting while the slow things are
> happening would be extremely helpful.
> -Nathan
> _______________________________________________
>
>
In the following messages , there are some values for possible combinations
on two identical main boards with 2 and 4 core processors :

http://lists.freebsd.org/pipermail/freebsd-current/2012-February/031836.html
http://lists.freebsd.org/pipermail/freebsd-current/2012-February/031912.html
http://lists.freebsd.org/pipermail/freebsd-current/2012-February/031928.html
http://lists.freebsd.org/pipermail/freebsd-current/2012-February/032012.html

FreeBSD 9.1 Stable ( 2013-03-09 )


top in console mode :

Load averages : 0.22 0.53 0.28
33 processes , 1 running , 32 sleeping

CPU  : 1.5 ... 3.5 % user
                     0.0 % nice
           0.6 .. 1.5 % system
           0.0 ... 0.4 interrupt
               ~ 0.95 % idle


top in X + FluxBox :


Load averages : 0.22 0.53 0.28

xterm ( top )
xterm ( Firefox )


44 processes , 1 running , 43 sleeping

CPU  : 1.5 ... 3.5 % user
                     0.0 % nice
           0.0 .. 1.5 % system
           0.0 ... 0.4 interrupt
               ~ 0.96 % idle

When there is no user activity : Sometimes  % user is increasing , % idle
decreasing .
When anything clicked in Firefox % user increasing , % idle decreasing .

Response is slow ( to open a menu sometimes reaching to minute ) .
Closing a menu is taking many seconds .

Thank you very much .


Mehmet Erol Sanliturk