Replace first-fit memory allocator with TLSF

[jserv]

This implements Two-Level Segregated Fit (TLSF) allocator optimized for real-time scenarios:

• O(1) malloc/free via bitmap-based segregated free lists
• Branchless clz/ctz using mask-based shifts for RV32I compatibility
• Immediate coalescing on free() to minimize fragmentation
• Configurable FL_INDEX_MAX via CONFIG_TLSF_FL_INDEX_MAX
• Bounds validation in block_remove/block_insert with panic on corruption
• Sentinel placement validation in mo_heap_init
• Block header sanity checks in free() to detect double-free

Test coverage:

• Block coalescing verification
• Realloc in-place growth
• Block splitting logic
• Heap exhaustion handling
• FL/SL boundary allocations
• Alignment verification
• Bitmap stress tests

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Summary by cubic

Replaced the first-fit allocator with a TLSF allocator to get O(1) malloc/free, lower fragmentation, and stronger corruption checks. API stays the same; adds extensive tests and a config knob for tuning.

• New Features

  • TLSF with bitmap free lists: O(1) malloc/free, immediate coalescing, better in-place realloc.
  • RV32I-friendly: branchless clz/ctz replacements.
  • Configurable CONFIG_TLSF_FL_INDEX_MAX (default 28) to tune max alloc size vs. metadata.
  • Safety hardening: range checks with panic on corruption, sentinel and header validation, double-free detection.
  • New tests for coalescing, splitting, FL/SL boundaries, alignment, heap exhaustion, and bitmap stress.

• Migration

  • No API changes; malloc/free/calloc/realloc work as before.
  • Review CONFIG_TLSF_FL_INDEX_MAX for your heap size (e.g., 24≈16MB, 28≈256MB, 30≈1GB).
  • Ensure mo_heap_init is given a zone large enough for TLSF headers; sentinel placement is validated at runtime.

^{Written for commit 48bb991. Summary will update on new commits.}

[github-actions]

Linmo CI Test Results

Overall Status: ✅ passed
Timestamp: 2026-01-28T19:01:06+00:00
Commit: 9cf086c

Toolchain Results

Toolchain	Build	Crash Test	Functional
GNU	✅ passed	✅ passed	✅ passed
LLVM	✅ passed	⏭️ skipped	⏭️ skipped

Application Tests

App	GNU	LLVM
cond	✅ passed	⏭️ skipped
coop	✅ passed	⏭️ skipped
cpubench	✅ passed	⏭️ skipped
echo	✅ passed	⏭️ skipped
hello	✅ passed	⏭️ skipped
mqueues	✅ passed	⏭️ skipped
mutex	✅ passed	⏭️ skipped
pipes	✅ passed	⏭️ skipped
pipes_small	✅ passed	⏭️ skipped
pipes_struct	✅ passed	⏭️ skipped
prodcons	✅ passed	⏭️ skipped
progress	✅ passed	⏭️ skipped
rtsched	✅ passed	⏭️ skipped
semaphore	✅ passed	⏭️ skipped
suspend	✅ passed	⏭️ skipped
test64	✅ passed	⏭️ skipped
test_libc	✅ passed	⏭️ skipped
timer	✅ passed	⏭️ skipped
timer_kill	✅ passed	⏭️ skipped
umode	⚠️	⏭️ skipped

Functional Test Details

Test	GNU	LLVM
mutex:data_consistency	✅ passed	⏭️ skipped
mutex:fairness	✅ passed	⏭️ skipped
mutex:mutual_exclusion	✅ passed	⏭️ skipped
mutex:overall	✅ passed	⏭️ skipped
semaphore:overall	✅ passed	⏭️ skipped
umode:[exception]_illegal_instruction	✅ passed	⚠️
umode:pass:_sys_tid()_returned	✅ passed	⚠️
umode:pass:_sys_uptime()_returned	✅ passed	⚠️

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Report generated from test-summary.toml