Slow performance on Linux?

[alshdavid]

Hi, I have written a wrapper util on top of ipc_channel that handles the handshake, swapping channels between the host/child and adds a request/response API.

The performance on my M1 MBP was great, but I was surprised to find that the performance on Linux was significantly slower!

So I wrote a benchmark to test it out. The benchmark sends n requests, blocking on their responses (100k requests means 200k messages over the channel).

I'm not sure if it's my configuration, perhaps something else is interfering, however here are my results

Hardware

• Windows: AMD 5950x - Windows 10
• Linux: AMD 5950x - Fedora 39
• MacOS: M1 Macbook Pro

Results

Platform	message count	duration
macos	10k	0.487s
windows	10k	0.356s
linux	10k	2.301s
macos	100k	1.550s
windows	100k	3.497s
linux	100k	13.608s
macos	1m	14.404s
windows	1m	34.769s
linux	1m	150.514s

Time taken for n round trip messages - Lower is better

I am have tried with/without the memfd option enabled and I have tried making this async (using tokio channels/threads) with the same outcome.

This is my wrapper (benchmarks are under examples)
https://github.com/alshdavid/ipc-channel-adapter

To run the benchmark run just bench {number_of_requests} e.g. just bench 100000

I'm investigating if another dependency is interfering, will update with my findings - but at the surface, any idea why this might be?

[alshdavid]

When running the benchmark using tokio and sending all the requests at once and waiting for them to return concurrently it's a lot better.

Tested with just bench-async

Platform	message count	duration
macos	100k	1.176s
windows	100k	0.368s
linux	100k	4.026s

[alshdavid]

I was able to replicate this on Ubuntu. Wonder where the performance loss is occuring

[mrobinson]

Hello, we've been testing this benchmark on our own systems. When plugged we see benchmark results in line with the ones you have posted for non-Linux platforms, @alshdavid. That said, we've noticed that power saving mode or throttling due to being unplugged has a massive effect on the results. For instance, when I switch my machine to "Power Saver" in Gnome the results I get are:

Ryzen 7 7840U / Ubuntu

Power Save	Count	Duration
Off	100k	3.072s
Off	1m	34.654s
On	100k	7.392s
On	1m	71.326s

Macbook M3 Max

Energy Mode	Count	Duration
High	100k	2.389s
High	1m	22.772s
Low	100k	2.720s
Low	1m	26.808s

Perhaps what's happening here is that the Linux implementation is very sensitive to power saving mode.

[mukilan]

I can confirm the same (i.e worse performance on power saving and numbers on par with OP's Windows and MacOS for performance mode) on NixOS 24.05, 24 × 12th Gen Intel® Core™ i7-12800HX, 64GB RAM

message count	power saving	perfomance mode
100K	21.441s	3.821s
1M	67.033s	24.460s