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dzbarsky merged 10 commits into from
Jul 31, 2026
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actiondfs: simplify caching, inode ownership, and staged directories #23

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a4795f7
actiondfs: remove unused cache and instrumentation state
dzbarsky Jul 31, 2026
bb87ade
actiondfs: simplify inode allocation and node ownership
dzbarsky Jul 31, 2026
04bbd91
actiondfs: simplify cached child lookup and validation
dzbarsky Jul 31, 2026
3d50207
actiondfs: consolidate directory protobuf parsing
dzbarsky Jul 31, 2026
c8fb1ce
actiondfs: simplify staged I/O and mount setup
dzbarsky Jul 31, 2026
b6270d4
actiondfs: derive staged readiness from published dentries
dzbarsky Jul 31, 2026
0df8d79
actiondfs: derive staging availability from mounted paths
dzbarsky Jul 31, 2026
c3a200b
actiondfs: parse owned mount options without extra allocations
dzbarsky Jul 31, 2026
31602ba
actiondfs: derive directory readiness from published state
dzbarsky Jul 31, 2026
ce724f4
actiondfs: simplify validated directory and blob caches
dzbarsky Jul 31, 2026
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197 changes: 99 additions & 98 deletions e2e/LLVM_VM_SMOKE_TIMINGS.md
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Original file line number Diff line number Diff line change
Expand Up @@ -27,49 +27,49 @@ subset of the VM `llvm-tblgen` graph.

## Latest Checked-In Result

- Generated: `2026-07-30 21:35:18 EDT`
- Command: `ACTIOND_BAZEL_BUILD_FLAGS="--jobs=64 --distdir=/private/tmp/actiond-audit-distdir --override_repository=llvm++osx+macos_sdk=/private/tmp/actiond-audit-macos-sdk" ACTIOND_LLVM_SMOKE_MAC_HOST=0 e2e/run_llvm_vm_smoke.sh`
- Output root: `/var/folders/p4/xn8y5q_j24l5xwgwd_jx5c340000gn/T/actiond-llvm-vm-smoke.04G6ke`
- Generated: `2026-07-31 14:08:55 EDT`
- Command: `ACTIOND_BAZEL_BUILD_FLAGS="--jobs=32 --distdir=/private/tmp/actiond-audit-distdir --override_repository=llvm++osx+macos_sdk=/private/tmp/actiond-audit-macos-sdk" ACTIOND_LLVM_SMOKE_MAC_HOST=0 e2e/run_llvm_vm_smoke.sh`
- Output root: `/var/folders/p4/xn8y5q_j24l5xwgwd_jx5c340000gn/T/actiond-llvm-vm-smoke.DAQ5ki`
- Workload: `@llvm-project//llvm:llvm-tblgen`, jobs=8
- VM warmup target: `//e2e:llvm_exec_warmup`
- Target and VM host platform: `@llvm//platforms:linux_arm64_musl`
- Build mode: `-c opt --strip=always --stripopt=--strip-all`
- VM warmup: `106.289s`; `2207 processes: 190 internal, 2017 remote`
- Measured VM build: `138.481s`; `2310 processes: 4 action cache hit, 204 internal, 2106 remote`
- VM warmup: `102.136s`; `2207 processes: 190 internal, 2017 remote`
- Measured VM build: `108.831s`; `2310 processes: 4 action cache hit, 204 internal, 2106 remote`
- Measured executions and timing records: `2106`
- Mac-host baseline: not run (`ACTIOND_LLVM_SMOKE_MAC_HOST=0`)

The prior checked-in run used the same jobs=8 and completed the warmup in
`88.364s` and measured build in `91.490s`. An intermediate run with the new
action isolation took `256.834s` for warmup and `140.328s` for the measured
build. Direct namespace cloning and the default-enabled seccomp BPF JIT reduced
the warmup to `106.289s`. The measured build remains slower than the prior
checked-in result; runner samples show scheduler and memory-contention outliers
of `389.600 ms` for process creation and `1,478.677 ms` for child setup.
The previous checked-in run used the same jobs=8 and completed the warmup in
`106.289s` and measured build in `138.481s`. The current warmup is 3.9% faster,
and the measured build is 21.4% faster with the same 2,106 measured actions.
An earlier run before action isolation completed the warmup in `88.364s` and
the measured build in `91.490s`. An intermediate action-isolation run took
`256.834s` for warmup and `140.328s` for the measured build.

## Filesystem Comparison With Prior Checked-In Run

Counters include both warmup and measured builds.

| Counter | Prior | Current |
| ------------------------------------ | ----------: | ----------: |
| actiondfs mounts | 4,122 | 4,108 |
| root directory parses | 1,405 | 1,403 |
| cached directory hits | 163,011 | 162,614 |
| cached directory misses | 6,606 | 6,603 |
| directory blob reads | 6,605 | 6,602 |
| staged ensure-directory calls | 16,012 | 15,949 |
| staged ensure-directory components | 16 | 15 |
| actiondfs mounts | 4,108 | 4,123 |
| root directory parses | 1,403 | 1,407 |
| cached directory hits | 162,614 | 163,045 |
| cached directory misses | 6,603 | 6,620 |
| directory blob reads | 6,602 | 6,619 |
| staged ensure-directory calls | 15,949 | 16,001 |
| staged ensure-directory components | 15 | 16 |
| staged ensure-directory existing | 0 | 0 |
| staged ensure-directory created | 16 | 15 |
| staged parent dentry hits | 15,996 | 15,934 |
| blob-path cache hits | 460,692 | 459,163 |
| blob-path cache misses | 6,883 | 6,881 |
| staged ensure-directory created | 15 | 16 |
| staged parent dentry hits | 15,934 | 15,985 |
| blob-path cache hits | 459,163 | 460,970 |
| blob-path cache misses | 6,881 | 6,970 |
| blob-path cache evictions | 0 | 0 |
| staged backing open attempts | 15,825 | 15,782 |
| staged backing open lookup | 0.595 ms | 0.866 ms |
| staged `copy_file_range` successes | 3,828 | 3,819 |
| staged `copy_file_range` fallbacks | 0 | 1 |
| blob-path cache insertion races | 0 | 0 |
| staged backing open attempts | 15,782 | 15,828 |
| staged backing open lookup | 0.866 ms | 0.961 ms |
| staged `copy_file_range` successes | 3,819 | 3,828 |
| staged `copy_file_range` fallbacks | 1 | 0 |

The workload retained the same 2,017 warmup actions and 2,106 measured actions.
Root-directory parsing, directory blob reads, staged parent-directory reuse, and
Expand All @@ -81,10 +81,10 @@ All timing values are milliseconds.

| Stage | Min | p25 | p50 | p75 | p95 | Mean | Max |
| --------------------- | ----: | -----: | -----: | -----: | -------: | ------: | --------: |
| total | 6.799 | 27.671 | 58.352 | 279.327 | 2134.781 | 444.223 | 15195.751 |
| input fetch/setup | 0.421 | 0.583 | 0.656 | 1.138 | 8.916 | 3.328 | 302.326 |
| execute | 6.003 | 25.217 | 54.401 | 267.455 | 2132.625 | 438.685 | 15191.620 |
| output upload/collect | 0.021 | 0.131 | 0.264 | 1.846 | 6.818 | 2.209 | 246.605 |
| total | 7.336 | 24.941 | 34.556 | 81.765 | 2004.324 | 368.775 | 20643.456 |
| input fetch/setup | 0.430 | 0.597 | 0.731 | 1.120 | 2.889 | 1.397 | 103.123 |
| execute | 6.722 | 23.152 | 32.609 | 78.352 | 1999.729 | 365.805 | 20636.110 |
| output upload/collect | 0.032 | 0.137 | 0.253 | 1.483 | 5.958 | 1.573 | 314.718 |

## Runner Timing

Expand All @@ -94,86 +94,87 @@ and lazy actiondfs input reads. All timing values are milliseconds.

| Runner Stage | Min | p25 | p50 | p75 | p95 | Mean | Max |
| -------------- | ----: | -----: | -----: | -----: | -------: | ------: | --------: |
| parent prepare | 0.058 | 0.092 | 0.116 | 0.166 | 0.708 | 0.577 | 84.637 |
| fork | 0.329 | 0.632 | 0.732 | 1.817 | 25.078 | 5.876 | 389.600 |
| child setup | 0.005 | 2.808 | 5.292 | 18.657 | 135.783 | 26.781 | 1478.677 |
| process/io | 1.242 | 18.012 | 33.622 | 194.182 | 2097.637 | 404.387 | 15184.102 |
| wait | 0.000 | 0.000 | 0.000 | 0.000 | 4.524 | 0.567 | 36.906 |
| stdio digest | 0.000 | 0.000 | 0.001 | 0.001 | 0.001 | 0.004 | 5.998 |
| parent prepare | 0.059 | 0.102 | 0.129 | 0.173 | 0.545 | 0.253 | 35.359 |
| fork | 0.319 | 0.533 | 0.622 | 1.065 | 5.682 | 1.817 | 109.051 |
| child setup | 0.008 | 2.191 | 3.728 | 7.078 | 27.496 | 7.697 | 215.098 |
| process/io | 1.622 | 17.841 | 25.036 | 59.728 | 1981.904 | 355.418 | 20631.081 |
| wait | 0.000 | 0.000 | 0.000 | 0.000 | 2.669 | 0.286 | 33.530 |
| stdio digest | 0.000 | 0.000 | 0.001 | 0.001 | 0.001 | 0.001 | 0.141 |

## actiondfs Counters

These `/proc/actiondfs_stats` counters cover the VM lifetime.

| Counter | Value |
| ----------------------------- | --------------: |
| mounts | 4,108 |
| root directory parses | 1,403 |
| cached directory requests | 169,217 |
| cached directory hits | 162,614 |
| cached directory misses | 6,603 |
| lookups | 1,403,982 |
| lookup hits | 839,807 |
| lookup negative | 564,175 |
| blob open attempts | 472,646 |
| blob-path cache hits | 459,163 |
| blob-path cache misses | 6,881 |
| mounts | 4,123 |
| root directory parses | 1,407 |
| cached directory requests | 169,665 |
| cached directory hits | 163,045 |
| cached directory misses | 6,620 |
| lookups | 1,407,099 |
| lookup hits | 842,187 |
| lookup negative | 564,912 |
| blob open attempts | 474,559 |
| blob-path cache hits | 460,970 |
| blob-path cache misses | 6,970 |
| blob-path cache evictions | 0 |
| node blob cache hits | 470,582 |
| node blob cache misses | 466,044 |
| backing reads | 413,804 |
| backing read bytes | 1,300,645,948 |
| mmap calls | 52,958 |
| mmap bytes | 1,895,503,368,192 |
| blob-path cache insertion races | 0 |
| node blob cache hits | 472,567 |
| node blob cache misses | 467,940 |
| backing reads | 415,500 |
| backing read bytes | 1,303,975,362 |
| mmap calls | 53,239 |
| mmap bytes | 1,901,676,589,056 |
| mmap failures | 0 |
| directory blob reads | 6,602 |
| directory blob bytes | 2,731,622 |
| directory blob reads | 6,619 |
| directory blob bytes | 2,731,829 |

## Staged Filesystem Counters

| Counter | Value |
| ------------------------------------ | ----------: |
| staged ensure-directory calls | 15,949 |
| staged ensure-directory components | 15 |
| staged ensure-directory calls | 16,001 |
| staged ensure-directory components | 16 |
| staged ensure-directory existing | 0 |
| staged ensure-directory created | 15 |
| staged parent dentry hits | 15,934 |
| staged inode lookups | 1,403,982 |
| staged inode unstaged-parent skips | 1,328,837 |
| staged inode lookup hits | 35,395 |
| staged inode lookup negative | 39,750 |
| staged inode input-directory merges | 18,319 |
| staged backing open attempts | 15,782 |
| staged ensure-directory created | 16 |
| staged parent dentry hits | 15,985 |
| staged inode lookups | 1,407,099 |
| staged inode unstaged-parent skips | 1,331,723 |
| staged inode lookup hits | 35,524 |
| staged inode lookup negative | 39,852 |
| staged inode input-directory merges | 18,388 |
| staged backing open attempts | 15,828 |
| staged backing open failures | 0 |
| staged backing open total | 13.436 ms |
| staged backing open lookup | 0.866 ms |
| staged backing open file | 10.146 ms |
| staged create calls/successes | 11,947 |
| staged backing open total | 14.863 ms |
| staged backing open lookup | 0.961 ms |
| staged backing open file | 11.764 ms |
| staged create calls/successes | 11,984 |
| staged mkdir calls/successes | 198 |
| staged rename calls/successes | 3,804 |
| staged size updates/successes | 3,865 |
| staged write calls | 36,648 |
| staged write bytes | 104,099,831 |
| staged `copy_file_range` successes | 3,819 |
| staged `copy_file_range` bytes | 29,413,418 |
| staged `copy_file_range` fallbacks | 1 |

The staged-negative filter skipped 1,328,837 lookups with known-unstaged
parents. Of 3,820 `copy_file_range` attempts, 3,819 succeeded and one used the
buffered fallback.
| staged rename calls/successes | 3,819 |
| staged size updates/successes | 3,876 |
| staged write calls | 37,194 |
| staged write bytes | 106,356,427 |
| staged `copy_file_range` successes | 3,828 |
| staged `copy_file_range` bytes | 31,630,764 |
| staged `copy_file_range` fallbacks | 0 |

The staged-negative filter skipped 1,331,723 lookups with known-unstaged
parents. All 3,828 `copy_file_range` attempts succeeded without a buffered
fallback.

## CAS Put-File Promotion Counters

| Counter | Value |
| ------------------------------------ | ---------: |
| CAS put-file calls | 7,925 |
| CAS promotion attempts | 7,925 |
| CAS promotion success | 2,088 |
| CAS existing-blob hits | 5,837 |
| CAS promoted bytes | 32,204,511 |
| CAS digest bytes | 80,077,779 |
| CAS promotion digest | 762.362 ms |
| CAS promotion rename | 219.052 ms |
| CAS put-file calls | 7,949 |
| CAS promotion attempts | 7,949 |
| CAS promotion success | 2,089 |
| CAS existing-blob hits | 5,860 |
| CAS promoted bytes | 37,922,351 |
| CAS digest bytes | 90,256,303 |
| CAS promotion digest | 961.559 ms |
| CAS promotion rename | 145.351 ms |
| CAS cross-device fallbacks | 0 |
| CAS permission fallbacks | 0 |
| CAS put-file copy calls | 0 |
Expand All @@ -182,19 +183,19 @@ buffered fallback.

| Counter | Value |
| ------------------------------------ | ---------: |
| ByteStream file reads | 4,025 |
| ByteStream file bytes | 57,704,579 |
| ByteStream file reads | 4,045 |
| ByteStream file bytes | 63,436,296 |
| ByteStream buffered reads | 0 |
| gRPC response tasks started | 36,160 |
| gRPC response tasks started | 36,255 |
| gRPC response tasks failed | 0 |
| gRPC response concurrency waits | 0 |
| gRPC data frames | 36,948 |
| gRPC file payload frames | 6,895 |
| gRPC `sendfile` attempts/successes | 6,895 |
| gRPC `sendfile` bytes | 57,704,579 |
| gRPC data frames | 37,396 |
| gRPC file payload frames | 7,263 |
| gRPC `sendfile` attempts/successes | 7,263 |
| gRPC `sendfile` bytes | 63,436,296 |
| gRPC `sendfile` fallbacks | 0 |

The measured TCP-to-vsock bridge logged two connections, 28.36 MiB from client
The measured TCP-to-vsock bridge logged two connections, 28.03 MiB from client
to guest, 37.37 MiB from guest to client, and zero read/write pump errors.
ByteStream reads remained file-backed and all 6,895 gRPC `sendfile` attempts
ByteStream reads remained file-backed and all 7,263 gRPC `sendfile` attempts
succeeded.
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