sched-ext/scx
Nov 2024 – Feb 2026
8 Months active
Languages Used
CRustBPF
Technical Skills
BPFKernel DevelopmentSynchronization PrimitivesSystem ProgrammingConcurrencyLinux Kernel Development
Dan Schatzberg
PROFILE
Dan Schatzberg
Dan Schatzberg developed and maintained the sched-ext/scx repository, focusing on advanced Linux kernel scheduling extensions using BPF, C, and Rust. Over eight months, Dan engineered features such as dynamic cell lifecycle management, per-CPU dispatch queues, and a unified RAII-based resource management framework, addressing concurrency, resource allocation, and system stability. His work included implementing robust synchronization primitives, timer-driven configuration updates, and diagnostic utilities for crash analysis, all aimed at improving reliability and maintainability. By refactoring core scheduling logic and enhancing observability, Dan ensured scalable, predictable performance and safer resource handling, demonstrating deep expertise in kernel development and system programming.
Overall Statistics
Feature vs Bugs
69%Features
Repository Contributions
18Total
Bugs
4
Commits
18
Features
9
Lines of code
4,341
Activity Months8
Your Network
88 peopleShared Repositories
88
Work History
February 2026
2 Commits • 1 Features
Feb 1, 2026Month 2026-02 — sched-ext/scx: Delivered a unified RAII-based resource management framework for BPF with kernel-style cleanup macros and migrated scx_layered to use scoped guards, achieving safer, more maintainable resource handling without changing behavior.
2 Commits • 1 Features
Feb 1, 2026Month 2026-02 — sched-ext/scx: Delivered a unified RAII-based resource management framework for BPF with kernel-style cleanup macros and migrated scx_layered to use scoped guards, achieving safer, more maintainable resource handling without changing behavior.
February 2026
October 2025
6 Commits • 3 Features
Oct 1, 2025October 2025 focused on observability, scalability, and stability for the sched-ext/scx mitosis subsystem. Deliveries span enhanced debugging of initialization sequences, a larger scalable BPF interface, and robust race-condition fixes, complemented by a resilient fallback path for exiting tasks to the root cgroup. These changes enable faster root-cause analysis, reduced incident latency, and improved system stability with modest memory overhead.
October 2025
6 Commits • 3 Features
Oct 1, 2025October 2025 focused on observability, scalability, and stability for the sched-ext/scx mitosis subsystem. Deliveries span enhanced debugging of initialization sequences, a larger scalable BPF interface, and robust race-condition fixes, complemented by a resilient fallback path for exiting tasks to the root cgroup. These changes enable faster root-cause analysis, reduced incident latency, and improved system stability with modest memory overhead.
September 2025
1 Commits • 1 Features
Sep 1, 20252025-09 monthly summary: Focused on reliability and resource management for sched-ext/scx. Delivered a timer-based tick() in the scx_mitosis BPF to ensure periodic configuration updates and implemented correct CPU reclamation back to the root cgroup. These changes improve update reliability, reduce drift when CPUs are idle, and enhance overall stability.
1 Commits • 1 Features
Sep 1, 20252025-09 monthly summary: Focused on reliability and resource management for sched-ext/scx. Delivered a timer-based tick() in the scx_mitosis BPF to ensure periodic configuration updates and implemented correct CPU reclamation back to the root cgroup. These changes improve update reliability, reduce drift when CPUs are idle, and enhance overall stability.
September 2025
August 2025
1 Commits • 1 Features
Aug 1, 2025August 2025 monthly summary for sched-ext/scx: Delivered dynamic cell lifecycle management driven by cgroup cpuset configurations with a focused refactor of BPF logic to support dynamic lifecycle changes. This work improves resource allocation and cleanup as cpuset assignments change, contributing to better scalability and resilience of the scheduling extension.
August 2025
1 Commits • 1 Features
Aug 1, 2025August 2025 monthly summary for sched-ext/scx: Delivered dynamic cell lifecycle management driven by cgroup cpuset configurations with a focused refactor of BPF logic to support dynamic lifecycle changes. This work improves resource allocation and cleanup as cpuset assignments change, contributing to better scalability and resilience of the scheduling extension.
July 2025
1 Commits • 1 Features
Jul 1, 2025July 2025 performance summary for sched-ext/scx focused on delivering enhanced observability and crash diagnostics for the scx_mitosis scheduler. Implemented a crash dump handler and diagnostic utilities, enabling richer crash outputs, cell/task state dumps (including CPU masks and virtual times), and structural improvements through basis_vtime in task_ctx. No major bug fixes documented this month; primary emphasis was feature delivery and maintainability to accelerate issue triage and reliability across the scheduler subsystem.
1 Commits • 1 Features
Jul 1, 2025July 2025 performance summary for sched-ext/scx focused on delivering enhanced observability and crash diagnostics for the scx_mitosis scheduler. Implemented a crash dump handler and diagnostic utilities, enabling richer crash outputs, cell/task state dumps (including CPU masks and virtual times), and structural improvements through basis_vtime in task_ctx. No major bug fixes documented this month; primary emphasis was feature delivery and maintainability to accelerate issue triage and reliability across the scheduler subsystem.
July 2025
June 2025
5 Commits • 1 Features
Jun 1, 2025June 2025 monthly summary for sched-ext/scx. Focused on stabilizing the Mitosis scheduler’s CPU affinity and scheduling paths, delivering a per-CPU dispatch queues feature and essential code hygiene. These changes deliver more predictable performance, better CPU utilization across cells, and reduced risk of LO_FALLBACK-induced stalls in production.
June 2025
5 Commits • 1 Features
Jun 1, 2025June 2025 monthly summary for sched-ext/scx. Focused on stabilizing the Mitosis scheduler’s CPU affinity and scheduling paths, delivering a per-CPU dispatch queues feature and essential code hygiene. These changes deliver more predictable performance, better CPU utilization across cells, and reduced risk of LO_FALLBACK-induced stalls in production.
March 2025
1 Commits • 1 Features
Mar 1, 2025March 2025 monthly summary for sched-ext/scx: Delivered static CPU pinning support for scx_mitosis Scheduler, refactoring to remove dynamic cell creation from userspace, and simplify cpuset-based cgroup handling, laying groundwork for improved performance and predictability. No major bug fixes were recorded this month; stability improvements were achieved via the refactor.
1 Commits • 1 Features
Mar 1, 2025March 2025 monthly summary for sched-ext/scx: Delivered static CPU pinning support for scx_mitosis Scheduler, refactoring to remove dynamic cell creation from userspace, and simplify cpuset-based cgroup handling, laying groundwork for improved performance and predictability. No major bug fixes were recorded this month; stability improvements were achieved via the refactor.
March 2025
November 2024
1 Commits
Nov 1, 2024Month 2024-11: Strengthened correctness and reliability of the sched-ext/scx integration by implementing robust synchronization for the scx_mitosis BPF cell assignments. The change ensures scheduling events complete after a scheduler tick, addressing a race condition that could leave events incomplete. Delivered a focused fix with clear commit trace and impact on reliability.
November 2024
1 Commits
Nov 1, 2024Month 2024-11: Strengthened correctness and reliability of the sched-ext/scx integration by implementing robust synchronization for the scx_mitosis BPF cell assignments. The change ensures scheduling events complete after a scheduler tick, addressing a race condition that could leave events incomplete. Delivered a focused fix with clear commit trace and impact on reliability.
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Quality Metrics
Correctness88.4%
Maintainability87.8%
Architecture87.8%
Performance80.6%
AI Usage20.0%
Skills & Technologies
Programming Languages
BPFCRust
Technical Skills
BPFBPF programmingC programmingConcurrencyDebuggingKernel DevelopmentKernel developmentLinux Kernel DevelopmentPerformance OptimizationResource ManagementResource managementSynchronization PrimitivesSystem Programmingkernel developmentresource management
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