Window Assisted Load Tracking (WALT) as an alternative to PELT utilization tracking in the Linux Scheduler

This proposal has been rejected.

60 Minute BoF session
Scheduled: Thursday, November 3, 2016 from 8:00 – 9:00pm in Sweeney F

One Line Summary

Theory and Data on why we believe WALT is better than PELT for real world mobile or interactive use cases from a perf-per-waiit perspective.


Window based load tracking in the Linux scheduler has been successfully commercialized on ARM based chipsets as an alternative to the existing PELT based load and utilization tracking. WALT is now in the Android common kernel as well. WALT has been used to track task demand and CPU utilization to guide task placement and guide frequency in the Linux scheduler, and has shown improvements in interactive workloads in the mobile world over PELT. In this BoF we intend to present data on x86 server/desktop workloads as well as start a discussion on how to proceed with WALT in mainline and/or PELT improvements in general.


  • Vikram Mulukutla

    Qualcomm Innovation Center


    I’m a software engineer working for the Linux scheduler team at Qualcomm.