[prev in list] [next in list] [prev in thread] [next in thread] 

List:       kde-core-devel
Subject:    Re: Building speed on multi-cpu systems
From:       Andriy Rysin <arysin () gmail ! com>
Date:       2009-02-22 3:23:59
Message-ID: 3e02eb610902211923l28e0538ape909805bdcf23342 () mail ! gmail ! com
[Download RAW message or body]

2009/2/21 Michael Pyne <mpyne@purinchu.net>

> On Saturday 21 February 2009, Alex Merry wrote:
> > On Sunday 22 February 2009 00:18:22 Andriy Rysin wrote:
> > > I have a 2-core cpu so I was trying to improve KDE compile speed and
> the
> > > quickest solution I could come up with to put "-j 4" in the makeobj
> > > script in the make command call (build speed was up ~30% and I in a
> > > monitor I can see all cores are fully busy now). Though this solution
> > > feels a bit hackish so I was wandering if there's a better/standard way
> > > to do that? If makeobj is the right place may be we could make it more
> > > generic so it tries to detect number of cores automagically (at least
> for
> > > some most popular platforms)?
> >
> > Well, you could just pass -j4 to makeobj, which will pass it on to make.
> > The best place to put that depends on what you use to build kde. If you
> > use the bash scripts on techbase, then you can just edit the cmakekde
> > function, which uses -j2 by default.
> >
> > Alex
>
>
> Mind you probably the best option is -j 3 for a dual-core system (number of
> CPUs + 1). The one extra process is going to be the one doing I/O, the
> others will either be doing work on a CPU core or stuck waiting for I/O, so
> CPUs + 2 doesn't really help much.
>
That's what I used first but somehow when I first tried -j 3 some time ago I
saw some relatively big dents in my 100% cpu load graph. Interestingly I
retried it today and dents are much smaller, so I might stick to -j 3 as a
theoretically better number :)

Thanks,
Andriy

[Attachment #3 (text/html)]

<div class="gmail_quote">2009/2/21 Michael Pyne <span dir="ltr">&lt;<a \
href="mailto:mpyne@purinchu.net">mpyne@purinchu.net</a>&gt;</span><br><blockquote \
class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt \
0pt 0.8ex; padding-left: 1ex;"> <div style="font-family: &#39;Droid Sans Mono&#39;; \
font-size: 10pt; font-weight: 400; font-style: normal;"><div><div></div><div \
class="Wj3C7c">On Saturday 21 February 2009, Alex Merry wrote:<br> &gt; On Sunday 22 \
February 2009 00:18:22 Andriy Rysin wrote:<br> &gt; &gt; I have a 2-core cpu so I was \
trying to improve KDE compile speed and the<br> &gt; &gt; quickest solution I could \
come up with to put &quot;-j 4&quot; in the makeobj<br> &gt; &gt; script in the make \
command call (build speed was up ~30% and I in a<br> &gt; &gt; monitor I can see all \
cores are fully busy now). Though this solution<br> &gt; &gt; feels a bit hackish so \
I was wandering if there&#39;s a better/standard way<br> &gt; &gt; to do that? If \
makeobj is the right place may be we could make it more<br> &gt; &gt; generic so it \
tries to detect number of cores automagically (at least for<br> &gt; &gt; some most \
popular platforms)?<br> &gt;<br>
&gt; Well, you could just pass -j4 to makeobj, which will pass it on to make. <br>
&gt; The best place to put that depends on what you use to build kde.  If you<br>
&gt; use the bash scripts on techbase, then you can just edit the cmakekde<br>
&gt; function, which uses -j2 by default.<br>
&gt;<br>
&gt; Alex<br>
<p style="margin: 0px; text-indent: 0px;"><br></p></div></div>Mind you probably the \
best option is -j 3 for a dual-core system (number of CPUs + 1).  The one extra \
process is going to be the one doing I/O, the others will either be doing work on a \
CPU core or stuck waiting for I/O, so CPUs + 2 doesn&#39;t really help much.<br> \
</div></blockquote><div>That&#39;s what I used first but somehow when I first tried \
-j 3 some time ago I saw some relatively big dents in my 100% cpu load graph. \
Interestingly I retried it today and dents are much smaller, so I might stick to -j 3 \
as a theoretically better number :)<br> <br></div></div>Thanks,<br>Andriy<br>



[prev in list] [next in list] [prev in thread] [next in thread]