How long does it take to install kernel (linux 3.2.5) on 12.04 using make install -j 4 command?
My terminal is displaying this for around 40 minutes now.
root@user-desktop:/usr/src/linux-3.2.5# make install -j 4
sh /usr/src/linux-3.2.5/arch/x86/boot/install.sh 3.2.5 arch/x86/boot/bzImage \
System.map "/boot"
run-parts: executing /etc/kernel/postinst.d/dkms 3.2.5 /boot/vmlinuz-3.2.5
It depends on the hardware especially the CPU. Here is a poll result which might help you to see. But, normally it is between 1-2 hours.
With a SSD and a Sandy Bridge clocked at 4 GHz on demand, it took ~ 8 mins with HT on and make -j14.
My first successful kernel compile was of the 3.2 kernel on a K8 Mobile Sempron 1.8 GHz with 512 MB of single-channel DDR and an ATA-100 5200 RPM hard disk included just about every module in mainline, because I didn't know what I was doing. It took 11 hours!
My most recent kernel, also 3.2, but now on a Pentium Dual Core T2370 with 2 GB dual-channel DDR2 and a SATA-3 SSD and all the unneeded modules turned off took 1 hour 48 minutes. It can vary a lot.
On a 64 CPU machine with lots of disks in RAID, ~5-8 minutes, with most of that being consumed in the final debian packaging step.
-jnumber than the number of physical cores in the machine, there are actually various reasons why using a higher number may still provide better performance: Not all threads will always use 100% of the processor resources available to them (this is the main reason, and the basis for some recommendations that the-jnumber always be higher than the number of physical cores), the CPU may have hyperthreading so there are more logical processors than physical cores, and so forth. And-j 4will at least run, even if you have fewer than 4 cores.