USB4STREAM Adding Busy Poll Option For Lower Latency At The Cost Of Increased CPU Cycles
Intel engineers have developed a new feature for Linux 7.2 called USB4STREAM, which allows for quick data transfers between USB4 connected systems. A busy poll mode is now being added to provide lower-latency data transfers at the expense of increased CPU activity.
Intelligence analysis by Llama
Intel engineers have developed a new feature for Linux 7.2 called USB4STREAM, which allows for quick data transfers between USB4 connected systems. A busy poll mode is now being added to provide lower-latency data transfers at the expense of increased CPU activity.
Imagine you're sending a package to your friend who lives on the other side of town. Normally, you would have to wait for the package to be delivered, but with USB4STREAM, you can send the package directly to your friend's house, which makes it arrive faster. However, this method uses more energy and makes the CPU work harder.
Analysis
A New Feature for Linux 7.2 - USB4STREAM
Intel engineers have developed a new feature for Linux 7.2 called USB4STREAM, which allows for quick data transfers between USB4 connected systems. This feature is designed to provide a simple way for transferring raw packets between hosts using USB4/Thunderbolt.
Busy Poll Mode for Lower Latency
A busy poll mode is now being added to provide lower-latency data transfers at the expense of increased CPU activity. This mode can be toggled via the /sys/kernel/config/thunderbolt/stream/[xdomain].[service]/$name/busy_poll interface. The queued patch explains that using interrupts and scheduling workers increase latency, so latency-critical applications may want to avoid that.
The Cost of Lower Latency
The cost for lower latency is that this burns more CPU cycles and things like poll(2) cannot be used. This means that users who require low-latency data transfers will have to sacrifice some CPU performance in order to achieve their desired results.
Key points
- Intel engineers have developed a new feature for Linux 7.2 called USB4STREAM, which allows for quick data transfers between USB4 connected systems.
- A busy poll mode is now being added to provide lower-latency data transfers at the expense of increased CPU activity.
- The cost for lower latency is that this burns more CPU cycles and things like poll(2) cannot be used.
If this development plays out positively, users who require low-latency data transfers will be able to achieve their desired results without sacrificing too much CPU performance. This could lead to improved performance in applications such as gaming and video editing.
However, the increased CPU activity required for lower-latency data transfers could lead to overheating and reduced system lifespan. Additionally, users who do not require low-latency data transfers may find that the increased CPU activity is unnecessary and wasteful.
