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Groups > comp.os.linux.misc > #13775 > unrolled thread

multi cpus

Started by"john@wexfordpress.com" <john@wexfordpress.com>
First post2015-02-28 06:01 -0800
Last post2015-03-01 12:32 +1100
Articles 11 — 10 participants

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  multi cpus "john@wexfordpress.com" <john@wexfordpress.com> - 2015-02-28 06:01 -0800
    Re: multi cpus Pascal Hambourg <boite-a-spam@plouf.fr.eu.org> - 2015-02-28 15:15 +0100
      Re: multi cpus Robert Heller <heller@deepsoft.com> - 2015-02-28 08:52 -0600
      Re: multi cpus Baho Utot <baho-utot@columbus.rr.com> - 2015-02-28 15:51 -0500
    Re: multi cpus Tim Watts <tw_usenet@dionic.net> - 2015-02-28 14:51 +0000
    Re: multi cpus William Unruh <unruh@invalid.ca> - 2015-02-28 18:31 +0000
      Re: multi cpus Robert Heller <heller@deepsoft.com> - 2015-02-28 13:11 -0600
        Re: multi cpus Bobbie Sellers <bliss-sf4ever@dslextreme.com> - 2015-02-28 13:35 -0800
      Re: multi cpus Andreas Kohlbach <feb15.5.ankman@spamgourmet.net> - 2015-02-28 16:31 -0500
      Re: multi cpus Jean-David Beyer <jeandavid8@verizon.net> - 2015-03-05 21:11 -0500
    Re: multi cpus faeychild <faeychild@nomail.afraid.org> - 2015-03-01 12:32 +1100

#13775 — multi cpus

From"john@wexfordpress.com" <john@wexfordpress.com>
Date2015-02-28 06:01 -0800
Subjectmulti cpus
Message-ID<851587d0-01da-4d3e-9bb4-c2e29b7d098f@googlegroups.com>
My computer seems to bog down on certain apps like scribus, swriter etc. Yet when 
I check "top" the app in question is using 100% of the cpu. In fact I have three cpus. Is it possible that only one is being used? If so, how do I fix this? 
Slackware 14.1.

John Culleton

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#13777

FromPascal Hambourg <boite-a-spam@plouf.fr.eu.org>
Date2015-02-28 15:15 +0100
Message-ID<mcsiis$23m8$1@saria.nerim.net>
In reply to#13775
Hello,

john@wexfordpress.com a écrit :
> My computer seems to bog down on certain apps like scribus, swriter etc. Yet when 
> I check "top" the app in question is using 100% of the cpu. In fact I have three cpus. Is it possible that only one is being used? If so, how do I fix this? 
> Slackware 14.1.

Check that /proc/cpuinfo lists the three CPUs. Otherwise, check that
multiprocessing (SMP) is enabled in the BIOS and the kernel config.

However if the busy task is monothread, more CPUs won't help.

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#13780

FromRobert Heller <heller@deepsoft.com>
Date2015-02-28 08:52 -0600
Message-ID<XY-dnfJNrsvfS2zJnZ2dnUU7-dGdnZ2d@giganews.com>
In reply to#13777
At Sat, 28 Feb 2015 15:15:55 +0100 Pascal Hambourg <boite-a-spam@plouf.fr.eu.org> wrote:

> 
> Hello,
> 
> john@wexfordpress.com a écrit :
> > My computer seems to bog down on certain apps like scribus, swriter etc. Yet when 
> > I check "top" the app in question is using 100% of the cpu. In fact I have three cpus. Is it possible that only one is being used? If so, how do I fix this? 
> > Slackware 14.1.
> 
> Check that /proc/cpuinfo lists the three CPUs. Otherwise, check that
> multiprocessing (SMP) is enabled in the BIOS and the kernel config.
> 
> However if the busy task is monothread, more CPUs won't help.

Right, it is important to understand that having multiple cpus does not help 
if the *applications* you are running are not multi-threaded.  Very often many 
applicates are not multi-threaded, and are not necessiarily even good 
candidates for multi-threading.

What does your memory usage look like?  Running out of physical memory can 
also bog things down, even more so than CPU saturation.

>                                                 

-- 
Robert Heller             -- 978-544-6933
Deepwoods Software        -- Custom Software Services
http://www.deepsoft.com/  -- Linux Administration Services
heller@deepsoft.com       -- Webhosting Services
                                                                       

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#13791

FromBaho Utot <baho-utot@columbus.rr.com>
Date2015-02-28 15:51 -0500
Message-ID<3bm9sb-8th.ln1@raspberry-pi.bildanet.com>
In reply to#13777
On 02/28/15 09:15, Pascal Hambourg wrote:
> Hello,
>
> john@wexfordpress.com a écrit :
>> My computer seems to bog down on certain apps like scribus, swriter etc. Yet when
>> I check "top" the app in question is using 100% of the cpu. In fact I have three cpus. Is it possible that only one is being used? If so, how do I fix this?
>> Slackware 14.1.
>
> Check that /proc/cpuinfo lists the three CPUs. Otherwise, check that
> multiprocessing (SMP) is enabled in the BIOS and the kernel config.
>
> However if the busy task is monothread, more CPUs won't help.
>

monothread?  Isn't that what you use for fishing line now a days?

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#13778

FromTim Watts <tw_usenet@dionic.net>
Date2015-02-28 14:51 +0000
Message-ID<e819sb-h93.ln1@squidward.dionic.net>
In reply to#13775
On 28/02/15 14:01, john@wexfordpress.com wrote:
> My computer seems to bog down on certain apps like scribus, swriter etc. Yet when
> I check "top" the app in question is using 100% of the cpu. In fact I have three cpus. Is it possible that only one is being used? If so, how do I fix this?
> Slackware 14.1.
>
> John Culleton
>


Run "top" from a terminal window, hit "1" and you'll see how busy each 
CPU is.

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#13784

FromWilliam Unruh <unruh@invalid.ca>
Date2015-02-28 18:31 +0000
Message-ID<mct1hv$je3$3@dont-email.me>
In reply to#13775
On 2015-02-28, john@wexfordpress.com <john@wexfordpress.com> wrote:
> My computer seems to bog down on certain apps like scribus, swriter etc. Yet when 
> I check "top" the app in question is using 100% of the cpu. In fact I have three cpus. Is it possible that only one is being used? If so, how do I fix this? 
> Slackware 14.1.

Most programs can use only one cpu. They are not designed for parallel
operation. So, unless you rewrite the programs, or persuade the writer
to write them in a parallel processor form, ( a gift of $10000 would
probably help in that) there is nothing you can do. 

>
> John Culleton

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#13785

FromRobert Heller <heller@deepsoft.com>
Date2015-02-28 13:11 -0600
Message-ID<DuydnU1tlvdTj2_JnZ2dnUU7-LGdnZ2d@giganews.com>
In reply to#13784
At Sat, 28 Feb 2015 18:31:27 +0000 (UTC) William Unruh <unruh@invalid.ca> wrote:

> 
> On 2015-02-28, john@wexfordpress.com <john@wexfordpress.com> wrote:
> > My computer seems to bog down on certain apps like scribus, swriter etc. Yet when 
> > I check "top" the app in question is using 100% of the cpu. In fact I have three cpus. Is it possible that only one is being used? If so, how do I fix this? 
> > Slackware 14.1.
> 
> Most programs can use only one cpu. They are not designed for parallel
> operation. So, unless you rewrite the programs, or persuade the writer
> to write them in a parallel processor form, ( a gift of $10000 would
> probably help in that) there is nothing you can do. 

Many programs would not benefit from multi-threading. Any GUI program that is
not doing anything computationly intensive would get little or no benefit from
multi-threading. Multi-threading is most useful for server daemons (handling
multiple connection requests concurrently) and computationly intensive
programs (running computation in parallel). Certain other programs where
multiple concurrent activities are possible or advantagious (like a web
browser [eg FF] downloading multiple files for a web site -- eg html in one
thread, css in another, javascript in another, images in yet another, etc.).

Most of the time having multiple CPUs in a *desktop* machine helps when you
are actually running multiple programs OR have background daemons also running
(eg your desktop machine is also acting as a server). This includes running
virtual machines on your desktop.

> 
> >
> > John Culleton
>                                                                                                        

-- 
Robert Heller             -- 978-544-6933
Deepwoods Software        -- Custom Software Services
http://www.deepsoft.com/  -- Linux Administration Services
heller@deepsoft.com       -- Webhosting Services
                                                                                   

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#13796

FromBobbie Sellers <bliss-sf4ever@dslextreme.com>
Date2015-02-28 13:35 -0800
Message-ID<mctc9o$vhq$1@dont-email.me>
In reply to#13785
On 02/28/2015 11:11 AM, Robert Heller wrote:
> At Sat, 28 Feb 2015 18:31:27 +0000 (UTC) William Unruh <unruh@invalid.ca> wrote:
>
>>
>> On 2015-02-28, john@wexfordpress.com <john@wexfordpress.com> wrote:
>>> My computer seems to bog down on certain apps like scribus, swriter etc. Yet when
>>> I check "top" the app in question is using 100% of the cpu. In fact I have three cpus. Is it possible that only one is being used? If so, how do I fix this?
>>> Slackware 14.1.
>>
>> Most programs can use only one cpu. They are not designed for parallel
>> operation. So, unless you rewrite the programs, or persuade the writer
>> to write them in a parallel processor form, ( a gift of $10000 would
>> probably help in that) there is nothing you can do.
>
> Many programs would not benefit from multi-threading. Any GUI program that is
> not doing anything computationly intensive would get little or no benefit from
> multi-threading. Multi-threading is most useful for server daemons (handling
> multiple connection requests concurrently) and computationly intensive
> programs (running computation in parallel). Certain other programs where
> multiple concurrent activities are possible or advantagious (like a web
> browser [eg FF] downloading multiple files for a web site -- eg html in one
> thread, css in another, javascript in another, images in yet another, etc.).
>
> Most of the time having multiple CPUs in a *desktop* machine helps when you
> are actually running multiple programs OR have background daemons also running
> (eg your desktop machine is also acting as a server). This includes running
> virtual machines on your desktop.
>
>>
>>>
>>> John Culleton

	Not all programs but some such as fwbackups will run 2 of my 4 
processors at 100% or close to it and 2 with lower percentages of
utilization.  That is 4 processors in an AMD A10.  Running KSysGuard
to get a visual representation which may have added to the work load.

	Next time I run fwbackups I will use top or htop so that I
can post the output here.

	bliss

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#13795

FromAndreas Kohlbach <feb15.5.ankman@spamgourmet.net>
Date2015-02-28 16:31 -0500
Message-ID<874mq5pvsh.fsf@usenet.ankman.de>
In reply to#13784
William Unruh wrote on 28. February 2015:
>
> On 2015-02-28, john@wexfordpress.com <john@wexfordpress.com> wrote:
>> My computer seems to bog down on certain apps like scribus, swriter etc. Yet when 
>> I check "top" the app in question is using 100% of the cpu. In fact I have three cpus. Is it possible that only one is being used? If so, how do I fix this? 
>> Slackware 14.1.
>
> Most programs can use only one cpu. They are not designed for parallel
> operation.

While some claim they can but don't.

Like the MESS emulator (part of MAME) here. Although I cannot see in the
verbose output whether or not it uses multi-treading, I am sure I compiled
it in. But that is what top tells me about my CPU (2 core AMD):

%Cpu0  : 22.0 us,  6.3 sy, 11.3 ni, 59.3 id,  0.0 wa,  0.0 hi,  1.0 si, 0.0 st
%Cpu1  : 99.7 us,  0.0 sy,  0.0 ni,  0.0 id,  0.0 wa,  0.0 hi,  0.3 si, 0.0 st

  PID USER      PR  NI    VIRT    RES    SHR S  %CPU %MEM     TIME+
  COMMAND
16625 user    20   0  424788 295956  33996 R 103.1  7.9   1:20.34 mess.comp

So one core is 0.0 idle, while the other is doing some other things I
have running. If those things wouldn't run now I would have close to
100 idle on the other core: one is working like a slave, the other is doing
nothing.

The mess.comp process uses 103% on ONE core instead of 100%.

Anyway, MESS itself runs very slow, skips 10 frames (that's the maximum I
allow) while running the emulated system (I just tried a Sharp X68000
from 1987) on 30%. I know that even if both CPU cores would be available
for 100% I couldn't get 100% speed for this system. And even if I just
emulate the Nintendo Entertainment System (came to the US in 1985) I
barely just have about 100% speed with no frame skip.
-- 
Andreas

I wish my grass was emo. Then it would cut itself.

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#13951

FromJean-David Beyer <jeandavid8@verizon.net>
Date2015-03-05 21:11 -0500
Message-ID<mdb2ct0ols@news4.newsguy.com>
In reply to#13784
On 02/28/2015 01:31 PM, William Unruh wrote:
> On 2015-02-28, john@wexfordpress.com <john@wexfordpress.com> wrote:
>> My computer seems to bog down on certain apps like scribus, swriter etc. Yet when 
>> I check "top" the app in question is using 100% of the cpu. In fact I have three cpus. Is it possible that only one is being used? If so, how do I fix this? 
>> Slackware 14.1.
> 
> Most programs can use only one cpu. They are not designed for parallel
> operation. So, unless you rewrite the programs, or persuade the writer
> to write them in a parallel processor form, ( a gift of $10000 would
> probably help in that) there is nothing you can do. 
> 
>>
>> John Culleton
True, but some programs do.

IIRC, IBM's DB2 database management system can use a lot of CPUs if
necessary. There is a main process that does the obvious things, like
SQL processing. But there are buffer managers and IO readers and writers
that can, and do, run asynchronously. Most people would not wish to run
DB2 on their desktops, but at one time, it was the only really good one
available for UNIX type systems.

PostgreSQL is very practical on a desktop, but the desktop has to be
properly configured. I ran that for quite a few years. It was useful to
have a an IO writer for each hard drive used by the DBMS. I had six SCSI
hard drives on two separate disk controllers on different internal data
busses. It worked very well.

But when Firefox gets hung up, it uses 100% of whatever processor it is
on even when it does not seem to be doing anything. It is at times like
that that I am glad to have multiple processors (or cores), so I can do
something until Firefox becomes unconfused.

-- 
  .~.  Jean-David Beyer          Registered Linux User 85642.
  /V\  PGP-Key:166D840A 0C610C8B Registered Machine  1935521.
 /( )\ Shrewsbury, New Jersey    http://linuxcounter.net
 ^^-^^ 21:00:01 up 5 days, 5:08, 3 users, load average: 4.44, 4.46, 4.38

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#13800

Fromfaeychild <faeychild@nomail.afraid.org>
Date2015-03-01 12:32 +1100
Message-ID<mctq5k$ggv$1@dont-email.me>
In reply to#13775
john@wexfordpress.com wrote:

> My computer seems to bog down on certain apps like scribus, swriter etc.
> Yet when I check "top" the app in question is using 100% of the cpu. In
> fact I have three cpus. Is it possible that only one is being used? If so,
> how do I fix this? Slackware 14.1.


No one has mentioned it yet, but "htop" will give a bit more detail
-- 
faeychild
Running kde on 3.14.32-desktop-1.mga4 kernel.
Mageia release 4 (Official) for x86_64

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