While compiling MPlayer git on 3.7.0, I noticed the attached messages. I 
then compiled 3.6.10, without any message being printed by the kernel, 
and thought it could be due to MPlayer being compiled on tmpfs, while 
the kernel on ext4. But compiling MPlayer on ext4 didn't change 
anything.

I booted on 3.6.10 and couldn't reproduce it.

According to 'free', swap isn't used at all during the compilation.

I'm also attaching my .config.

It's an Athlon 64 X2 Dual Core Processor 4000+ with 2Gb of DDR2.