# A Quickie.... How many mins/hrs to compile kernel

## fwempa

Thanks

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## Varean

Well, from my expeirience, it doesn't take long.  Maybe around 20 minutes. Tops.

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## Sourcecode

With a Pentium 3 1GhZ ->  25-35Minutes

So... just Compile your Kernel and when he is compiling, just take a coffee and relaxx.

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## Ma3oxuct

It takes five minutes for me on my 3Ghz P4 and my AMD64 3000+. I ussually take a bathroom break when I get to the kernel compilation step.

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## thagame

i only have a P3 800mhz and it took around 30 - 35 min roughly.

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## Exil

About 20-30 min. It depends wich WM I'm using.

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## mark_alec

 *Exil wrote:*   

> About 20-30 min. It depends wich WM I'm using.

 Uh, the time to compile the kernel should not be influenced by the window manager you use.

~10 minutes on a 2.4 celeron, ~40 minutes on a 450 k6-2

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## opqdan

 *mark_alec wrote:*   

>  *Exil wrote:*   About 20-30 min. It depends wich WM I'm using. Uh, the time to compile the kernel should not be influenced by the window manager you use.
> 
> ~10 minutes on a 2.4 celeron, ~40 minutes on a 450 k6-2

 

Not neccesarily, if he is compiling the kernel while running KDE it will take longer than using while using fluxbox, simply due to the resources that it requires in the background and the overhead on the processor task switching.

When I compile my kernel (or anything else that is big or important) I kill X (along with any other big apps) and use the console.  The speed increase is small but for large jobs (kernel, kde, openoffice etc) it can save a couple minutes.  For an X compile, it probably saves almost an hour.

It takes me about 10 - 15 minutes to compile my kernel (P4 2.4Ghx, 512MB RAM), but then I've gone through every option and only enabled those that I need, rather than using the defaults+.

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## nixnut

Moved from Installing Gentoo to Kernel & Hardware.

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## codergeek42

About 20 minutes on my P4 2.4 GHz.

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## i92guboj

I dont know what do you, guys & girls, are putting into the kernel... For me, with all the stuff I need, it takes about 7-8 minutes on an athlon-xp 1600+ / 256 mb.

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## fwempa

with so many options to choose from, does anyone know of a really informative and explanation rich resource for determining which options to choose for the kernel.  i am struggling to learn all i can about my system and gentoo.  is actually quite fun, and the post on here are really appreciated

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## i92guboj

 *fwempa wrote:*   

> with so many options to choose from, does anyone know of a really informative and explanation rich resource for determining which options to choose for the kernel.  i am struggling to learn all i can about my system and gentoo.  is actually quite fun, and the post on here are really appreciated

 

Only your experience and many unsuccessfull attempts can illustrate you about that. As a important advice, I can say that you should always have a working kernel, and experiment with another one, so, if you cant boot you from your custom kernel you can use the other.

As a brief guidance, the more important things are the drivers for your chipset, to choose the correct cpu type and the support for the boot device (into the kernel, not as module), that, usually is a ide driver for the hd, but can also require sata support, or scsi or whatever your main boot device is.

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## Smoothhound

Slightly OT, but it's worth pointing out that using ccache makes kernel compilations *lot* quicker when recompiling repeatedly with only a couple of config changes.

HTH

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## DaNIsH

<10 mins at an estimate. Never really timed it.

2ghz Pentium M, 1gb ram.

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## i92guboj

 *Smoothhound wrote:*   

> Slightly OT, but it's worth pointing out that using ccache makes kernel compilations *lot* quicker when recompiling repeatedly with only a couple of config changes.
> 
> HTH

 

The recompilation of the kernel with only a few changes (trivial changes) lasts already a few seconds, so there is no point in using ccache for that.

Still, note that it depends on what changes do you make. For example, to add a few networking drivers or a filesystem will take a few seconds of compilation time. But if you change a non trivial thing (like preemptivity, debugging or cpu settings) you need to recompile the whole kernel again, even if you did not a make clean, because all the rest of the stuff depends on these settings.

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## guduri

< 5min on an amd64 3000+ Venice (overclocked to 2.2 Ghz) and a gig of memory

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## chunderbunny

Some processors are just slow at compiling, it takes about an hour to compile a kernel on my 600MHz Via C3 (curse that crappy FPU!) but only 5 - 10 minutes on my Athlon 2600.

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## fwempa

Recompiling with added features take but secconds, BUT what if i want to eliminate support for stuff that i dont need.  Does that free up space, lessen the footprint, or generally streamline the system?  Is there an good method to determine what i can safely get rid of.?

Always greast help here, Thanks

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## AaronPPC

 *Quote:*   

> Does that free up space, lessen the footprint, or generally streamline the system?

 

Yes, yes, and yes.

 *Quote:*   

> Is there an good method to determine what i can safely get rid of.?

 

I found that lspci, experience, and a willingness to experiment will get you most of the way there.

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## nephros

About 5.5 hours from the end of make clean to the end of make bzImage on a 486SX 25MHz w/ 24MB RAM and an SCSI disk.

About 7+ hours if you switch "Turbo" off (16MHz).

Measures are for a 2.0.3Xish kernel tree(about 6MB compressed), more recent source trees tend to be much larger (~ 37MB), so take that into account.

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HTH.

 :Very Happy: 

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## kormoc

DeletedLast edited by kormoc on Mon Dec 24, 2018 8:42 am; edited 1 time in total

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## Raistlin

kormoc: I don't know what you've compiled, but it impossibly can be the linux kernel. A few months ago I was working on a mainframe; my lpar had 6 CPUs. All of them were about 1.5 gig. Even with make  -j7 it took almost a minute...   :Rolling Eyes: 

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## Raistlin

alternatively: show your config - I guess almost nothing is enabled. Without anything to compile, it _will_ run very fast, of course.

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## Raistlin

```
goliath: ~>cat /proc/cpuinfo 

processor       : 0

vendor_id       : AuthenticAMD

cpu family      : 6

model           : 8

model name      : AMD Athlon(tm) XP 2600+

```

```
goliath: ~>cat /proc/meminfo 

MemTotal:      1555340 kB

```

```
goliath: /usr/src/linux-2.6.12-r6>make clean

goliath: /usr/src/linux-2.6.12-r6>time make -j2

...

real    8m5.493s

user    6m56.581s

sys     0m37.402s
```

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## kormoc

DeletedLast edited by kormoc on Mon Dec 24, 2018 8:42 am; edited 1 time in total

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## kormoc

DeletedLast edited by kormoc on Mon Dec 24, 2018 8:42 am; edited 1 time in total

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## e-ipi

I get about 11~15 minutes for a full compile on a 1.5GHz ppc32 (with an astounding 166MHz system bus).  I leave a lot out of the kernel, but I use xfs,  which seems to take much longer to compile support for than ext2.  

I usually have 2 emacs, Firefox, several rxvts, and afterstep classic running in the background.  These days I play xgalaga while waiting.

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## Raistlin

 :Razz:  You've definitively made me curious   :Wink: 

I'll do some testing and come back --> no X, other tweaks.

could it be that gcc 3.4 is that much faster? 

```
goliath: ~>gcc --version

gcc (GCC) 3.3.6 (Gentoo 3.3.6, ssp-3.3.6-1.0, pie-8.7.8)

Copyright (C) 2003 Free Software Foundation, Inc.

```

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## player1

It only takes me about 10 minutes, give or take. But I have a really tight kernel configuration. My hardware isn't particularly "1337" but it's decent by todays standards. It all depends really.

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## Raistlin

I tested the same in runlevel 1... saved about 1 min.

```
cd /usr/src/linux-2.6.12-r6/

goliath linux-2.6.12-r6 #> make clean

..

goliath linux-2.6.12-r6 #> make -j2

real   7m12.999s

user   6m37.456s

sys   0m30.210s
```

1min 30 sec is unrealistic  :Evil or Very Mad: 

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## thomasvk

Mine takes typically between 5 and 20 minutes on Athlon XP 3000+ w/ 1GB ram. When I do it I mostly just sit at my computer watching it. I always think it'll only be a minute and I end up staring 10 minutes at a compiling kernel.  :Surprised: 

I find the lspci, lsusb handy and lsmod when booted from the livecd. To find stuff quicker you can use the / key in the menu. Also having a look at the specs of your motherboard in you m/b manual or online to find out your chipset and stuff is a good practice.  :Smile: 

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