LITTLE Cores on big.LITTLE
To quote arm.com:
“Arm big.LITTLE technology is a heterogeneous processing architecture that uses two types of processor. ”LITTLE” processors are designed for maximum power efficiency while ”big” processors are designed to provide maximum compute performance. With two dedicated processors, the big.LITTLE solution is able to adjust to the dynamic usage pattern for smartphones, tablets and other devices. Big.LITTLE adjusts to periods of high-processing intensity, such as those seen in mobile gaming and web browsing, alternate with typically longer periods of low-processing intensity tasks such as texting, e-mail and audio, and quiescent periods during complex apps. “
In other words, big.LITTLE processors use LITTLE side of processor for power efficiency and the “big” side for more intensive tasks. As a result, the battery usage is optimized.
Restrict to LITTLE cores – Chrome
Google Chrome is experimenting with the use of LITTLE cores to reduce battery usage. According to code change and flag that we spotted today, Chrome threads will use LITTLE cores on devices with ARM’s big.LITTLE cores.
“Restrict to LITTLE cores: Restricts Chrome threads to LITTLE cores on devices with big.LITTLE or similar CPU architectures.”
According to the feature request bug, this is an experiment to evaluate impact of this on power consumption, smoothness, and other system health metrics etc.
“Run an experiment in which all of Chrome/WebView work is scheduled to run only on little cores and evaluate impact of this on power consumption, smoothness, and other system health metrics etc.
This includes putting infrastructure in place to opt Chromium threads into little-core-only execution.”
As the code comments suggest, this is clearly an experiment. We might have to wait a lot to see the results from this experiments. However, if you are curious, when the flag becomes available, you can test this on supported ARM devices.
Now that competition from the Edge browser is heating up, Chrome really needs to become more efficient. Chrome will have to go easy on battery and processor to drop some of the bad press that it has attracted.
What do you think the impact of this change is going to be? Let us know in the comments section.