Messages in this thread | | | Date | Tue, 15 Sep 2009 11:22:37 +0300 | From | Ozan Çağlayan <> | Subject | Tricks to speed up kernel builds |
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Hi,
I'd googled a lot about the $subject but couldn't find any detailed guide about it. So, the followings are what I understand from what I've found:
1. Build inside a tmpfs to avoid I/O bottlenecks, 2. Use ccache, 3. Switch governor to performance if supported, 4. Pass -j to gnu make to parallelize the build process, 5. Don't build debug symbols a.k.a set CONFIG_DEBUG_INFO=n 6. There are a bunch of sched patches in tip which apparently improves things during kbuild 7. Distribute the work into the local network using icecream, distcc.
For the -j part, how many jobs should we pass to it? I've seen people passing
- NR_of_cores+1 - NR_of_cores x 2 (I think that this is useful when there's 2 threads of execution per core like HyperThreading?) - 64, 128, etc. regardless of the number of cores (Is it really useful regardless of the CPU)
The curious question is *what build times can you get* with your typical systems using your speedup tricks (quad core, dual core, etc.) ? What are other tricks that I can use to even more speed up the build?
Do you really use icecream/distcc on your daily test builds?
How about nicing/ionicing make on an idle system? Will it make any difference?
Thanks a lot Ozan Caglayan
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