Re: [gentoo-embedded] slow compilation on NFS Root -> use an external USB hard disk ;-)

[Mike Frysinger]

On Sunday 27 May 2007, Christopher Friedt wrote:
> Using the stage3 gentoo arm-softfloat-linux-uclibc filesystem, I had for
> some time been natively compiling packages for my target system, with
> the root located over NFS.
>
> Normally it wasn't so bad - sure it was quite slower than
> cross-compiling. But one thing I hated about cross compiling was
> randomly running into packages that use some sort of pkgconfig file that
> I didn't have present, or trying to run some native program in configure
> and coming up with an error.

ive found NFSv3 + TCP actually isnt so shabby ... you have to make sure to use 
those options in the kernel cmdline though as the default is NFSv2 + UDP

> When I got around to compiling the GNU Classpath (for use with jamvm,
> and stripped of all but the necessities), I found that compiling this
> app over an NFS root failed quite often because of out-of-memory errors.
> The process was killed outright. Then I read somewhere about creating a
> swap file on an NFS root, using losetup to create a loop device, and
> using swapon to load that swap into the kernel's VM. That turned out to
> be the worst idea I think I've ever had, because the overhead of using
> RPC with the NFS root was probably of O^2 complexity at that point,
> especially considering all of the swapping that had to be done with such
> a huge compile, using jikes of course.

this is the biggest problem and ive found not worth the hassle if possible ... 
doing network swap (whether it be via nbd or nfs or ...) is just not usable

if your machine doesnt have enough physical ram to compile w/out -pipe, then 
it's time to search for another option :)
-mike