Developer Pinpoints the Cause of Pixel Scrolling Stutter, Suggests Fix

Pixel users have been frustrated for a long time with display stuttering while scrolling through apps. This issue has been sitting unresolved in Google’s Issue Tracker for quite some time now. Even though Google has acknowledged the problem, a fix still hasn’t been released. Instead, complaints on the Issue Tracker are marked as duplicates and closed, with users being advised to try newer Android builds. Unfortunately, the stuttering persists, with reports indicating it’s still noticeable on the Android 16 Developer Preview and Beta 1 builds.

Now, it seems a developer has uncovered the root cause of why Pixel phones struggle with scrolling performance. According to Sultan Alsawaf, a well-known Android kernel developer, the issue lies in how Pixel devices manage bandwidth (via Piunikaweb).

To break it down simply: imagine your Pixel phone as a busy office with workers (apps and processes) sharing limited desk space (bandwidth). If workers don’t take turns or communicate properly, the office becomes chaotic, slowing everything down. In this case, the “office administrator” (the system) isn’t effectively organizing who uses the desk space and when.

The Technical Problem

Alsawaf explains that the system was using the wrong kind of “lock” to manage bandwidth. Instead of using a strict lock (mutex_lock) that ensures only one worker uses the desk space at a time, it relied on a less restrictive lock (btsdev->lock). This allowed multiple workers to compete for space simultaneously, creating chaos. The result? Apps can’t properly calculate their bandwidth needs, leading to stuttering and lag during scrolling.

The Suggested Fix

The developer’s fix involves implementing a better “schedule” for bandwidth use, ensuring only one worker accesses the desk space at a time. He also addressed a second issue where the system wasn’t accurately calculating bandwidth needs in the first place.

Alsawaf has submitted his code changes to Google for consideration. He’s also implemented the fix in his custom kernel patch for Pixel 8 users. However, flashing custom kernels comes with risks—it could wipe your data or even brick your device. For this reason, it’s now up to Google to officially implement the fix in a software update, making it safe for all users.

What’s Next?

This discovery highlights the importance of properly managing system resources to ensure smooth user experiences. Now, users are hoping Google will take notice of this fix, test it thoroughly, and release an update to finally resolve the scrolling stutter issue. Until then, Pixel users will have to wait and see if their devices will soon perform as they should.