6 ms·

Kernel 5.4 compiled under 24 seconds. Insane.

by disintegore 7y ago

thebruce87m 7y ago
Compile on boot
- deleted 7y ago
  [deleted]
- kami8845 7y ago
  This comment made my day :)
- mkl 7y ago
  That was already a thing back in 2004: https://bellard.org/tcc/tccboot.html https://bellard.org/tcc/tccboot.html 15 seconds to compile and run a Linux kernel of the time (64MB RAM required!).
Someone1234 7y ago
That is insane. I'm surprised it can even go that low, I would have expected it to hit an IO bottleneck before then (large object files/linking/source reads, etc). Even with a fast SSD on my lowly i7, I often wind up sitting at IO or lock contention instead of actual CPU bottlenecks (although it could be argued faster CPU = faster lock release = faster compilation).
- zaarn 7y ago
  They used a Samsung Pro NVMe which should be able to hold almost all of the linux kernel sources in it's read cache without that many issues.
  - pradn 7y ago
    NVMes are magic. Just the same improvement that SSDs have over HDDs. Probably the only upgrade worth getting for my home PC at this point.
    - charwalker 7y ago
      Technically, 100%. I'm full SSD right now though which has a seriously noticeable difference from from HDD but for what I do most days NVME isn't justifiable. I see others who can take advantage of the speeds and do so with huge returns. I do have 2 super SFF HP boxes that only take NVME in the M.2 drive so have one on hand but it isn't installed at the moment.
- Beltiras 7y ago
  PCI-ex version 4, double the xfer rate. It can handle a massive 16 GB/s. Are there even disks that can handle that speed?
  - gameswithgo 7y ago
    not yet.
    - spoonalious 7y ago
      https://www.aorus.com/AORUS-Gen4-AIC-SSD-8TB https://www.aorus.com/AORUS-Gen4-AIC-SSD-8TB 15000MB/sec, available now for $3119 AUD.
      - wtallis 7y ago
        That's just four SSDs mounted on one riser card with a fan. If you're going to count the aggregate bandwidth of an array, then the question's almost meaningless.
- esotericn 7y ago
  The entire Linux kernel source tree will trivially fit in tmpfs in RAM. On one of these systems I'm fairly sure you could just whack the entire thing in /tmp and -j64 it, the compile artifacts aren't that big either.
  - trunc 7y ago
    I've done builds in /dev/shm/ on Xeon and Threadripper with only a trivial speed-up. If it can fit in tempfs, make/cc can just load it all into RAM anyway, so I guess you only reduce the build time by the time it takes for the first read. Which would explain why '-j' on a big codebase tends to trigger my OOM killer.
lazyjones 7y ago
With half the cores of the upcoming (early 2020) 3990X ...
yborg 7y ago
Now there is no excuse to not Install Gentoo.
- mastax 7y ago
  Hah! There is something cathartic about recompiling the world with -march=native even if it makes no noticable difference.
Scuds 7y ago
Would the best use of this CPU be in a group or multi-group build+integration server? It's $2000 for the CPU alone, so this can't be general-use.
- disintegore 7y ago
  I also imagine it'd be useful as a rendering machine for small to medium media companies.

Kernel 5.4 compiled under 24 seconds. Insane.

thebruce87m 7y ago

Compile on boot

deleted 7y ago
[deleted]
kami8845 7y ago
This comment made my day :)
mkl 7y ago
That was already a thing back in 2004: https://bellard.org/tcc/tccboot.html https://bellard.org/tcc/tccboot.html 15 seconds to compile and run a Linux kernel of the time (64MB RAM required!).

Someone1234 7y ago

That is insane. I'm surprised it can even go that low, I would have expected it to hit an IO bottleneck before then (large object files/linking/source reads, etc). Even with a fast SSD on my lowly i7, I often wind up sitting at IO or lock contention instead of actual CPU bottlenecks (although it could be argued faster CPU = faster lock release = faster compilation).

zaarn 7y ago
They used a Samsung Pro NVMe which should be able to hold almost all of the linux kernel sources in it's read cache without that many issues.
- pradn 7y ago
  NVMes are magic. Just the same improvement that SSDs have over HDDs. Probably the only upgrade worth getting for my home PC at this point.
  - charwalker 7y ago
    Technically, 100%. I'm full SSD right now though which has a seriously noticeable difference from from HDD but for what I do most days NVME isn't justifiable. I see others who can take advantage of the speeds and do so with huge returns. I do have 2 super SFF HP boxes that only take NVME in the M.2 drive so have one on hand but it isn't installed at the moment.
Beltiras 7y ago
PCI-ex version 4, double the xfer rate. It can handle a massive 16 GB/s. Are there even disks that can handle that speed?
- gameswithgo 7y ago
  not yet.
  - spoonalious 7y ago
    https://www.aorus.com/AORUS-Gen4-AIC-SSD-8TB https://www.aorus.com/AORUS-Gen4-AIC-SSD-8TB 15000MB/sec, available now for $3119 AUD.
    - wtallis 7y ago
      That's just four SSDs mounted on one riser card with a fan. If you're going to count the aggregate bandwidth of an array, then the question's almost meaningless.
esotericn 7y ago
The entire Linux kernel source tree will trivially fit in tmpfs in RAM. On one of these systems I'm fairly sure you could just whack the entire thing in /tmp and -j64 it, the compile artifacts aren't that big either.
- trunc 7y ago
  I've done builds in /dev/shm/ on Xeon and Threadripper with only a trivial speed-up. If it can fit in tempfs, make/cc can just load it all into RAM anyway, so I guess you only reduce the build time by the time it takes for the first read. Which would explain why '-j' on a big codebase tends to trigger my OOM killer.

lazyjones 7y ago

With half the cores of the upcoming (early 2020) 3990X ...

yborg 7y ago

Now there is no excuse to not Install Gentoo.

mastax 7y ago
Hah! There is something cathartic about recompiling the world with -march=native even if it makes no noticable difference.

Scuds 7y ago

Would the best use of this CPU be in a group or multi-group build+integration server? It's $2000 for the CPU alone, so this can't be general-use.

disintegore 7y ago
I also imagine it'd be useful as a rendering machine for small to medium media companies.