[systemd-devel] XDM and systemd --user

[Zbigniew Jędrzejewski-Szmek]

On Mon, Oct 01, 2012 at 10:55:14AM +0100, Colin Guthrie wrote:
> 'Twas brillig, and Zbigniew Jędrzejewski-Szmek at 01/10/12 09:42 did
> gyre and gimble:
> > On Sat, Sep 29, 2012 at 09:02:11PM +0100, Colin Guthrie wrote:
> >> 'Twas brillig, and Kok, Auke-jan H at 28/09/12 20:09 did gyre and gimble:
> >>> 1) people should fix 'make' to just allow `-j` without an argument
> >>> (seriously, dude ;^) )
> >>
> >> Going dangerously off-topic, but two points:
> >>
> >> If you're using -j I've always gone under the impression you want the
> >> value to be #cores+1, not #cores. That way you keep your machine working
> >> full tilt.
> >>
> >> But regardless, why not use "make -l" anyway? This way it's tied to
> >> system load which is likely a more prudent method to decide whether or
> >> not new make jobs are issued - e.g. if you happen to be running a make
> >> process that is io-intensive, you likely want to run less of them, but
> >> if you've got a couple jobs one of which is io intensive then some of
> >> your cpu cores might be mostly idle... -l should allow you to max things
> >> out better.
> > 
> > Yeah, -l seems better. But than you still want a load of #cores+1, no?
> > And -l requires an argument too, so it has exactly the same
> > inconvinience as -j.
> 
> I thought -l was based on the Load Average of the system which is
> separate from #cores. So if I like keeping my LA below 1.5, I'd just use
> -l 1.5. and this wouldn't really matter how many cores I have. That
> said, I'm prepared to be wrong here as I've not really read up about it
> much! :)

I would love to be proved wrong --- i.e. to learn that 'make -l'
adapts to the number of cores by itself. But as I understand it,
"load" is "the number of running or waiting to run process". If
'make -l' uses the same definition, than one would want #nrcores+1 at
least.

Zbyszek