facebook/jemalloc
Mar 2025 – Feb 2026
10 Months active
Languages Used
CShellC++
Technical Skills
Code RefactoringEvent HandlingMemory ManagementPerformance MonitoringPerformance OptimizationSystem Programming
Slobodan Predolac
PROFILE
Slobodan Predolac
Over ten months, Spredolac contributed to the facebook/jemalloc repository by developing and refining advanced memory management features, focusing on performance, configurability, and reliability. He implemented vectorized huge page purging, experimental hugification controls, and runtime observability using C, C++, and Shell scripting. His work included refactoring event systems, enhancing benchmarking accuracy, and introducing dynamic configuration options to support diverse workloads. Spredolac addressed concurrency and memory allocation edge cases, improved test determinism, and maintained code quality through documentation and formatting updates. His engineering demonstrated depth in low-level system programming, performance optimization, and robust debugging, resulting in a more maintainable allocator.
Overall Statistics
Feature vs Bugs
75%Features
Repository Contributions
27Total
Bugs
5
Commits
27
Features
15
Lines of code
5,193
Activity Months10
Your Network
480 peopleSame Organization
@fb.com459
Adnan AkhundovMember
Amir AyupovMember
Adan MorenoMember
Adarsh RajanikanthMember
Afraz SiddiquiMember
andrewjcgMember
agelunMember
Arnav AghavMember
Pooja AgarwalMember
Work History
February 2026
2 Commits • 1 Features
Feb 1, 2026February 2026 focused on stabilizing profiling and reducing configuration complexity in jemalloc. Delivered two prioritized changes: 1) Reverted the experimental fast path prefetch option from cache_bin (commit 2fe05dc6b818fb0d6d23e67bb6f097fb7208f5ca) to mitigate risk and avoid potential performance regressions; 2) Removed the built-in prof_threshold event to simplify profiling and enable user-defined threshold events (commit 7bf49ca68985cf2f1a8a6a9ee548295f32fa8ace). Business impact: reduced maintenance surface, clearer performance analysis, and greater flexibility for users to tailor profiling to their workloads. Technologies demonstrated: memory allocator internals, profiling instrumentation, commit-based traceability, and cross-team collaboration.
2 Commits • 1 Features
Feb 1, 2026February 2026 focused on stabilizing profiling and reducing configuration complexity in jemalloc. Delivered two prioritized changes: 1) Reverted the experimental fast path prefetch option from cache_bin (commit 2fe05dc6b818fb0d6d23e67bb6f097fb7208f5ca) to mitigate risk and avoid potential performance regressions; 2) Removed the built-in prof_threshold event to simplify profiling and enable user-defined threshold events (commit 7bf49ca68985cf2f1a8a6a9ee548295f32fa8ace). Business impact: reduced maintenance surface, clearer performance analysis, and greater flexibility for users to tailor profiling to their workloads. Technologies demonstrated: memory allocator internals, profiling instrumentation, commit-based traceability, and cross-team collaboration.
February 2026
November 2025
1 Commits • 1 Features
Nov 1, 2025November 2025: Delivered a new experimental Hugification configuration option for jemalloc to control memory allocation behavior, enabling exploration of hugification strategies for potential performance and memory-usage improvements. The feature is tracked in facebook/jemalloc with commit bfb63eaf41451d00fe8b82e9dd6e89d795b13dde.
November 2025
1 Commits • 1 Features
Nov 1, 2025November 2025: Delivered a new experimental Hugification configuration option for jemalloc to control memory allocation behavior, enabling exploration of hugification strategies for potential performance and memory-usage improvements. The feature is tracked in facebook/jemalloc with commit bfb63eaf41451d00fe8b82e9dd6e89d795b13dde.
October 2025
3 Commits • 1 Features
Oct 1, 2025October 2025 monthly summary for facebook/jemalloc focused on stability, correctness, and experimental feature exploration. Key outcomes include: (1) Documentation corrections in edata.h to fix spelling issues and improve accuracy (commit: 0669f70b6704870dda3061a04f5c10d66d838643); (2) Stability improvement in memory allocation: prevent premature release of shard mutex during page insertions to avoid potential race conditions and maintain mutex ownership during critical allocation phases (commit: 832a332c33aae4d90996c88fb089f21ccb224e1f); (3) Experimental THP/HPA option for Huge Page Allocation: introduce experimental_hpa_start_huge_if_thp_always to control HPA behavior when THP is always enabled, with refactoring of hpa_central_extract and corresponding tests (commit: 6ced85a8e5d73e882aa999a1fbc95b9312461804).
3 Commits • 1 Features
Oct 1, 2025October 2025 monthly summary for facebook/jemalloc focused on stability, correctness, and experimental feature exploration. Key outcomes include: (1) Documentation corrections in edata.h to fix spelling issues and improve accuracy (commit: 0669f70b6704870dda3061a04f5c10d66d838643); (2) Stability improvement in memory allocation: prevent premature release of shard mutex during page insertions to avoid potential race conditions and maintain mutex ownership during critical allocation phases (commit: 832a332c33aae4d90996c88fb089f21ccb224e1f); (3) Experimental THP/HPA option for Huge Page Allocation: introduce experimental_hpa_start_huge_if_thp_always to control HPA behavior when THP is always enabled, with refactoring of hpa_central_extract and corresponding tests (commit: 6ced85a8e5d73e882aa999a1fbc95b9312461804).
October 2025
September 2025
4 Commits • 1 Features
Sep 1, 2025September 2025 performance-focused month for facebook/jemalloc. Delivered improved benchmarking accuracy and memory management reliability. Key features include Pa Benchmark Enhancements with nanoseconds-based timing and updated insights, including clock-based timing in the benchmark outputs. Also delivered memory dehugification restoration during purging by reintroducing the dehugify function/variable and ensuring the dehugify hook is invoked during memory purge. These changes improve data fidelity for performance tuning and fix memory management edge cases that could affect stability under purge. Technologies demonstrated include low-level instrumentation, monotonic clock timing, and memory management hooks, with disciplined change management across feature和Bug Fixes.
September 2025
4 Commits • 1 Features
Sep 1, 2025September 2025 performance-focused month for facebook/jemalloc. Delivered improved benchmarking accuracy and memory management reliability. Key features include Pa Benchmark Enhancements with nanoseconds-based timing and updated insights, including clock-based timing in the benchmark outputs. Also delivered memory dehugification restoration during purging by reintroducing the dehugify function/variable and ensuring the dehugify hook is invoked during memory purge. These changes improve data fidelity for performance tuning and fix memory management edge cases that could affect stability under purge. Technologies demonstrated include low-level instrumentation, monotonic clock timing, and memory management hooks, with disciplined change management across feature和Bug Fixes.
August 2025
5 Commits • 4 Features
Aug 1, 2025August 2025 monthly summary for facebook/jemalloc: concise highlights of feature work, bug fixes, and measurable impact. Delivered improvements to process_madvise handling, huge page allocation, runtime observability, and code quality, with strong emphasis on performance, reliability, and maintainability.
5 Commits • 4 Features
Aug 1, 2025August 2025 monthly summary for facebook/jemalloc: concise highlights of feature work, bug fixes, and measurable impact. Delivered improvements to process_madvise handling, huge page allocation, runtime observability, and code quality, with strong emphasis on performance, reliability, and maintainability.
August 2025
July 2025
1 Commits
Jul 1, 20252025-07 Monthly Summary for facebook/jemalloc: Focused on stability in process management and test reliability. No new user-facing features shipped this month; major bug fix to stabilize process identification across forks.
July 2025
1 Commits
Jul 1, 20252025-07 Monthly Summary for facebook/jemalloc: Focused on stability in process management and test reliability. No new user-facing features shipped this month; major bug fix to stabilize process identification across forks.
June 2025
3 Commits • 2 Features
Jun 1, 2025June 2025 — Facebook/jemalloc: Delivered two experimental features focused on performance and observability, with configuration options to enable/disable. No major bugs fixed in this period according to the provided data. Business value centers on reduced allocation latency and enhanced diagnostics for memory-heavy workloads.
3 Commits • 2 Features
Jun 1, 2025June 2025 — Facebook/jemalloc: Delivered two experimental features focused on performance and observability, with configuration options to enable/disable. No major bugs fixed in this period according to the provided data. Business value centers on reduced allocation latency and enhanced diagnostics for memory-heavy workloads.
June 2025
May 2025
1 Commits • 1 Features
May 1, 2025May 2025 monthly summary for facebook/jemalloc focused on delivering a deterministic HPC memory allocation test capability and improving test reliability. Key delivery: a new HPC Test Shell Script that configures MALLOC_CONF to disable batching for memory allocation advice, enabling stable and predictable test results for non-vectorized high-performance workloads. The work is linked to an explicit test adjustment in non-vectorized HPC tests. No major user-reported bugs fixed this month in the jemalloc repo. Overall impact is improved test determinism, traceability, and confidence in performance baselines, supporting safer releases and more stable benchmark results.
May 2025
1 Commits • 1 Features
May 1, 2025May 2025 monthly summary for facebook/jemalloc focused on delivering a deterministic HPC memory allocation test capability and improving test reliability. Key delivery: a new HPC Test Shell Script that configures MALLOC_CONF to disable batching for memory allocation advice, enabling stable and predictable test results for non-vectorized high-performance workloads. The work is linked to an explicit test adjustment in non-vectorized HPC tests. No major user-reported bugs fixed this month in the jemalloc repo. Overall impact is improved test determinism, traceability, and confidence in performance baselines, supporting safer releases and more stable benchmark results.
April 2025
4 Commits • 2 Features
Apr 1, 2025April 2025 performance summary for the facebook/jemalloc workstream. Delivered vectorized huge page purge enhancements and an experimental SYS_process_madvise configuration, with targeted refactoring to support multi-page vectorization and expanded testing coverage. The work emphasizes business value through improved memory management efficiency, reduced purge overhead, and configurable experimentation for performance tuning across environments.
4 Commits • 2 Features
Apr 1, 2025April 2025 performance summary for the facebook/jemalloc workstream. Delivered vectorized huge page purge enhancements and an experimental SYS_process_madvise configuration, with targeted refactoring to support multi-page vectorization and expanded testing coverage. The work emphasizes business value through improved memory management efficiency, reduced purge overhead, and configurable experimentation for performance tuning across environments.
April 2025
March 2025
3 Commits • 2 Features
Mar 1, 2025March 2025 monthly summary for facebook/jemalloc. Key features delivered include vectorized purging for Huge Page Allocation (HPA) with a fallback to single purges when vectorized purge fails; adds a new purge hook and accompanying tests validating vectorized purge behavior and the fallback path. Thread event system improvements include a registry-based dynamic event system, removal of macros, and added support for user-defined events triggered on allocation/deallocation when stats are enabled. These changes improve memory management efficiency, observability, and configurability, providing business value by enhancing performance under high-memory workloads and simplifying future extensions.
March 2025
3 Commits • 2 Features
Mar 1, 2025March 2025 monthly summary for facebook/jemalloc. Key features delivered include vectorized purging for Huge Page Allocation (HPA) with a fallback to single purges when vectorized purge fails; adds a new purge hook and accompanying tests validating vectorized purge behavior and the fallback path. Thread event system improvements include a registry-based dynamic event system, removal of macros, and added support for user-defined events triggered on allocation/deallocation when stats are enabled. These changes improve memory management efficiency, observability, and configurability, providing business value by enhancing performance under high-memory workloads and simplifying future extensions.
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Quality Metrics
Correctness90.8%
Maintainability88.2%
Architecture86.0%
Performance82.2%
AI Usage20.0%
Skills & Technologies
Programming Languages
CC++Shell
Technical Skills
BenchmarkingBug FixBuild System ConfigurationC ProgrammingC programmingCode FormattingCode RefactoringCode ReviewConcurrencyConcurrency ControlDebuggingDocumentationError HandlingEvent HandlingLow-Level Programming
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