Compiling very slow

ukiuki · 10-06-2012, 08:11 AM

It pretty much depends on how much have to be compiled, the more modules the longer will take, I have done this on very old computers, takes about 5 hours on a 250Mhz with 64MB RAM, but only take about 20mins or less on a twin core machine and less than 15mins in a quad core machine, but, again, that depends on how much is being compiled. The more you tweak your kernel the better the results will be and less time will take to complete. Generic kernels bring TONS of things that you don't need. Strip it out !!

Regards

GazL · 10-06-2012, 08:14 AM

Quote:

Originally Posted by H_TeXMeX_H

I also use -j with the number of cores I have mostly to be able to do other things while its compiling, like browsing the web, without major slowdown.

Over-committing on the -j option is really only useful if you're seeing CPU IDLE or WAIT % >0, otherwise you're only going to slow the build down by introducing unnecessary task swapping overhead and I/O contention.. Over-commit too much and you can actually slow down the build by a significant factor.

No of cpu's +1 is a good rule of thumb but the best thing to do is watch top and tune things to your own system. make -j2 is optimal for me.

I've added the following to my kernel.Slackbuild script to maintain a decent user desktop experience while compiling

Code:

renice -n 19 $$ >/dev/null   # be kind, renice.
chrt -b -p 0 $$              # non-interactive batch scheduling class.

r.vaillancourt · 10-06-2012, 09:01 AM

Quote:

Originally Posted by business_kid

On paper, you and I have fairly similar boxes (AMD cpu, chipset, graphics). My time was for the command
time make
which does the bulk of the work. If you're up over the hour, something's wrong. I have a 667Mhz bus (advertising spec) and a 7200 rpm drive (HP Compaq 6715S).

There's nothing major wrong with Pat's generic kernel, if you have an initrd. One possibility that springs to mind is that you don't have the chipset driver in there, and you're not getting full speed out of the disk. Try your speed with this command

sudo hdparm -tT /dev/sda

Mine does 755MB/s cached and 61.57MB/s direct. If yours is a lot off that, that could be the issue.

Ran hdparm -tT /dev/sda = 921.00 MB/sec and 75.59 MB/sec, not that far off your marks.

r.vaillancourt · 10-06-2012, 09:17 AM

Quote:

Originally Posted by ukiuki

It pretty much depends on how much have to be compiled, the more modules the longer will take, I have done this on very old computers, takes about 5 hours on a 250Mhz with 64MB RAM, but only take about 20mins or less on a twin core machine and less than 15mins in a quad core machine, but, again, that depends on how much is being compiled. The more you tweak your kernel the better the results will be and less time will take to complete. Generic kernels bring TONS of things that you don't need. Strip it out !!

Regards

Eloquently put. After looking at slacks huge and generic .configs, the generic .config is rather large compared to some custom .configs i found through googling.

r.vaillancourt · 10-06-2012, 09:30 AM

Thanks guys for all the responses, very helpful.
I just found this:
LINUX: Rute User's Tutorial and Exposition (Version 1.0.0) This should be included in every Slackware release.

Thanks for all the help, very much appreciated.

business_kid · 10-06-2012, 10:08 AM

Just for a speed comparison, I built Pat's generic config here on this similar box, twin turion @ 2Ghz, 3G ram, 4G swap.

time make -j2

65 minutes. I have a little on you speed wise (2Ghz vs 1,9Ghz) and less ram & swap. That's opposed to 16 minutes for what I actually need. A useful option to go for might be to load everything (wifi, usb storage, do an ipv6 ping, etc) and run

make localmodconfig

Didier Spaier · 10-06-2012, 11:04 AM

Though the "localmodconfig" target have been there from Linux 2.6.32 I don't recompile my kernel as I used to. As for my hardware the stock generic-smp kernel included in Slackware 14 works out of the box, I don't feel I really need it, at least for the time being. Plus, as my laptop is overheating when I use an aggressive -j parameter, I avoid using my two cores in parallel to compile.

H_TeXMeX_H · 10-06-2012, 11:07 AM

Quote:

Originally Posted by Didier Spaier

Though the "localmodconfig" target have been there from Linux 2.6.32 I don't recompile my kernel as I used to. As for my hardware the stock generic-smp kernel included in Slackware 14 works out of the box, I don't feel I really need it, at least for the time being. Plus, as my laptop is overheating when I use an aggressive -j parameter, I avoid using my two cores in parallel to compile.

Clean out the dust with compressed air.

Didier Spaier · 10-06-2012, 11:14 AM

Quote:

Originally Posted by H_TeXMeX_H

Clean out the dust with compressed air.

I even opened it and there was not that much dust, the fan seems to work properly. May be the thermal paste is no more efficient but I am a little scared by the idea of disassembling it again and not being able of reassembling it afterwards as I have two left hands...

H_TeXMeX_H · 10-06-2012, 12:27 PM

Well, if you opened it, you probably should have changed the paste. Not much to do now, I can't recommend opening laptops as it is quite difficult to put it back together. Maybe a cooling pad will help a small bit.

TobiSGD · 10-06-2012, 12:37 PM

An overheating CPU is nothing that should be left in that state. If you don't want to do the necessary maintenance yourself (which is quite understandable with a laptop) I strongly recommend to bring it to your favorite local shop and let them do it. This way you will not only get the computing power you paid for, but also a longer lifetime of that device.

business_kid · 10-07-2012, 09:01 AM

I find it difficult to imagine the localmod config being perfect, although I'm recommending it. I like to choose some extras to prevent another compile down the road

@Didier Spaier: Get the dust out and the fans cleaned. A dry paintbrush and/or vacuum cleaner. The temperature cycling isn't good for the cpu, or anything else. Don't worry about the heat sink paste. You can replace it with more, or silicon grease is nearly as good. You can remove the heatsink, and stop there. Lift the old stuff with a fine blade, if it's atrophied.

titopoquito · 10-07-2012, 09:53 AM

Quote:

Originally Posted by Didier Spaier

I even opened it and there was not that much dust, the fan seems to work properly.

Sure about the dust? I recently did this with an old Laptop myself - first I thought there was no dust and just some material to damp vibrations (at one side of the fan) but at a closer look it was pure dust, looking a little bit like felt (the material made from wool). If the CPU is overheating and the fan is constantly turning and turning and turning, I would expect much dust to be drawn into the Laptop.

Didier Spaier · 10-07-2012, 10:30 AM

I feel a bit guilty of having hijacked this thread and have been too vague so I will first better characterize my overheating issue with thinkpad-acpi's help then if need be post the outcome in a new thread. Thanks to all who provided advises.

H_TeXMeX_H · 10-07-2012, 01:41 PM

Here's how long it takes to compile 3.4.13 on my Intel(R) Core(TM)2 Quad CPU Q9300 @ 2.50GHz

Code:

real	5m28.945s
user	17m11.804s
sys	1m58.368s

The kernel is custom and doesn't include everything.