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Reworking 30 lines of Linux code could cut power use by up to 30 percent

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Re: Reworking 30 lines of Linux code could cut power use by up to 30 percent

#21
post #10

Earlier quoted context omitted.

you don’t have to say “in datacenters” when talking about linux, that is the obvious context in the vast majority of cases

Why you think so? Especially for HN readers decent chunk is using Linux. (I typed this on Linux PC).

Agree. On reading the headline, I was hoping it would extend my laptop battery life.

Re: Reworking 30 lines of Linux code could cut power use by up to 30 percent

#23
Off topic: glad to read about Joe Damato again — such a blast from the past. I haven't read anything from him since I first read James Gollick posts about on tcmalloc and then learning about packagecloud.io which eventually led me to Joe's amazing posts.

Re: Reworking 30 lines of Linux code could cut power use by up to 30 percent

#24
post #21

Earlier quoted context omitted.

Why you think so? Especially for HN readers decent chunk is using Linux. (I typed this on Linux PC).

Agree. On reading the headline, I was hoping it would extend my laptop battery life.

Same here, I have used Linux as my main for a long time. Though, I would imagine that data centers do have more instances than the desktops and laptops around the world combined.

Re: Reworking 30 lines of Linux code could cut power use by up to 30 percent

#25
post #10
post #5

Linux added a busy polling feature for high performance networking. Most Linux software does not use it, but software used in datacenters (e.g. by CDNs) that does use it makes the system very energy inefficient when things are not busy. This patch gives the the kernel the ability to turn that off when not busy to regain energy efficiency until things become busy again. The article name is somewhat misleading, since i…

you don’t have to say “in datacenters” when talking about linux, that is the obvious context in the vast majority of cases

This is a naming mistake. You're taking "Linux" in the sense of "Linux Distribution", where the various competitors have seen most of their success in the datacenter.

This is specifically a change to the Linux kernel, which is much, much more broadly successful.

Re: Reworking 30 lines of Linux code could cut power use by up to 30 percent

#26
post #22

The flip side of this is meta having a hack that keeps their GPUs busy so that the power draw is more stable during llm training (eg don't want a huge power drop when synchronizing batches)

I thought of this too. Iirc it was bigger problem because surging spikes in power and cooling were harder and more costly to account for.

I'm not au fait with network data centres though, how similar are they in terms of their demands?

Re: Reworking 30 lines of Linux code could cut power use by up to 30 percent

#27
post #10
post #5

Linux added a busy polling feature for high performance networking. Most Linux software does not use it, but software used in datacenters (e.g. by CDNs) that does use it makes the system very energy inefficient when things are not busy. This patch gives the the kernel the ability to turn that off when not busy to regain energy efficiency until things become busy again. The article name is somewhat misleading, since i…

you don’t have to say “in datacenters” when talking about linux, that is the obvious context in the vast majority of cases

Indeed he has to.

Re: Reworking 30 lines of Linux code could cut power use by up to 30 percent

#28

This is really cool. As a high-performance computing professional, I've often wondered how much energy is wasted due to inefficient code and how much that is a problem as planetary compute scales up. For me, it feels like a moral imperative to make my code as efficient as possible, especially when a job will take months to run on hundreds of CPU.

My experience with HPC is only tangential to being a sysadmin for data taking and cluster management for a high energy physics project; I am interested on your thoughts about using generative AI to search out for potentially power inefficient code paths in codebases for potential improvement.

Re: Reworking 30 lines of Linux code could cut power use by up to 30 percent

#30

[flagged]

How is Gnome in any way relevant to bring up in the context of the kernel networking stack?

I mean I get it, you dislike Gnome for whatever reason and want to cast some shade - that part is clear. What I don't really understand is how you decided this context is somehow going to be received in a way to further your view... it's just so illogical that my reaction is "support the Gnome folks".

Actually - due to this comment I just donated $50 to the GNOME Foundation. Either the guerilla marketing worked, or your mission failed - in any case I hope this was an effective lesson in messaging.

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