pico: pin V toolchain to latest upstream commit

[enghitalo]

Summary

Pin the V toolchain used by frameworks/pico from c0624b274 to the latest upstream V master commit 6c4d26f1f.

Why this can improve benchmark results

Recent V upstream changes in this range include runtime-oriented improvements relevant to tight HTTP loops:

• Merged PR: builtin, cgen, checker: fix spawn-in-if/match-expr, zero-alloc error sentinel, cheaper slice marking, scalable GC vlang/v#27544
  • cheaper slice marking and scalable GC can reduce runtime overhead in allocation-heavy request paths.
• Merged PR: builtin: speed up single element array push (a << x), fixes #27468 vlang/v#27470
  • Speeds up single-element array push operations and closes Array single-element push (<<) 4-7x slower on master vs 0.5.1 (alloc, push_many, indexed-write unaffected) vlang/v#27468.
  • This can improve small-buffer append-heavy paths common in request/response handling.

Closed issue references

• Closed issue: Array single-element push (<<) 4-7x slower on master vs 0.5.1 (alloc, push_many, indexed-write unaffected) vlang/v#27468 (fixed by PR #27470)
• Closed issue: sync.Once: do/do_with_param can return before the callback completes (done flag set before f()) vlang/v#27456 (addressed by sync: fix ordering in Once and ManyTimes -- store count after f() completes vlang/v#27490; concurrency correctness/stability)

Scope

• Updated only: frameworks/pico/Dockerfile

[enghitalo]

/benchmark -f pico

[github-actions]

👋 /benchmark request received. A collaborator will review and approve the run.

[github-actions]

Benchmark Results

Framework: pico | Test: all tests

Test	Conn	RPS	CPU	Mem	Δ RPS	Δ Mem
pipelined	512	4,244,495	6290.0%	416MiB	~0%	-50.8%
pipelined	4096	4,257,608	6275.8%	701MiB	-0.8%	-0.3%
json	4096	2,131,290	6280.1%	1.7GiB	-0.6%	+41.7%

Full log

[info] CPU 6296.4% | Mem 646MiB

=== Best: 4244495 req/s (CPU: 6290.0%, Mem: 416MiB) ===
[info] saved results/pipelined/512/pico.json
httparena-bench-pico
httparena-bench-pico

==============================================
=== pico / pipelined / 4096c (tool=gcannon) ===
==============================================
[info] waiting for server...
[info] server ready

[run 1/3]
gcannon v0.5.3
  Target:    localhost:8080/pipeline
  Threads:   64
  Conns:     4096 (64/thread)
  Pipeline:  16
  Req/conn:  unlimited (keep-alive)
  Expected:  200
  Duration:  5s


  Thread Stats   Avg      p50      p90      p99    p99.9
    Latency   15.42ms   14.50ms   20.70ms   29.50ms   38.80ms

  21281322 requests in 5.00s, 21281322 responses
  Throughput: 4.25M req/s
  Bandwidth:  312.43MB/s
  Status codes: 2xx=21281322, 3xx=0, 4xx=0, 5xx=0
  Latency samples: 21281287 / 21281322 responses (100.0%)
[info] CPU 6240.1% | Mem 469MiB

[run 2/3]
gcannon v0.5.3
  Target:    localhost:8080/pipeline
  Threads:   64
  Conns:     4096 (64/thread)
  Pipeline:  16
  Req/conn:  unlimited (keep-alive)
  Expected:  200
  Duration:  5s


  Thread Stats   Avg      p50      p90      p99    p99.9
    Latency   15.39ms   14.40ms   20.70ms   29.00ms   34.60ms

  21291497 requests in 5.00s, 21287401 responses
  Throughput: 4.26M req/s
  Bandwidth:  312.52MB/s
  Status codes: 2xx=21287401, 3xx=0, 4xx=0, 5xx=0
  Latency samples: 21287322 / 21287401 responses (100.0%)
[info] CPU 6414.0% | Mem 698MiB

[run 3/3]
gcannon v0.5.3
  Target:    localhost:8080/pipeline
  Threads:   64
  Conns:     4096 (64/thread)
  Pipeline:  16
  Req/conn:  unlimited (keep-alive)
  Expected:  200
  Duration:  5s


  Thread Stats   Avg      p50      p90      p99    p99.9
    Latency   15.39ms   14.50ms   20.70ms   29.10ms   34.50ms

  21291113 requests in 5.00s, 21288041 responses
  Throughput: 4.26M req/s
  Bandwidth:  312.54MB/s
  Status codes: 2xx=21288041, 3xx=0, 4xx=0, 5xx=0
  Latency samples: 21288005 / 21288041 responses (100.0%)
[info] CPU 6275.8% | Mem 701MiB

=== Best: 4257608 req/s (CPU: 6275.8%, Mem: 701MiB) ===
[info] saved results/pipelined/4096/pico.json
httparena-bench-pico
httparena-bench-pico
[info] skip: pico does not subscribe to limited-conn

==============================================
=== pico / json / 4096c (tool=gcannon) ===
==============================================
[info] waiting for server...
[info] server ready

[run 1/3]
gcannon v0.5.3
  Target:    localhost:8080/
  Threads:   64
  Conns:     4096 (64/thread)
  Pipeline:  1
  Req/conn:  25
  Templates: 7
  Expected:  200
  Duration:  5s


  Thread Stats   Avg      p50      p90      p99    p99.9
    Latency   1.24ms    606us    993us   34.10ms   64.70ms

  10658496 requests in 5.00s, 10656450 responses
  Throughput: 2.13M req/s
  Bandwidth:  7.15GB/s
  Status codes: 2xx=10656450, 3xx=0, 4xx=0, 5xx=0
  Latency samples: 10656389 / 10656450 responses (100.0%)
  Reconnects: 424919
  Per-template: 1515939,1520675,1524537,1527267,1526962,1523393,1517616
  Per-template-ok: 1515939,1520675,1524536,1527266,1526962,1523393,1517616
[info] CPU 6280.1% | Mem 1.7GiB

[run 2/3]
gcannon v0.5.3
  Target:    localhost:8080/
  Threads:   64
  Conns:     4096 (64/thread)
  Pipeline:  1
  Req/conn:  25
  Templates: 7
  Expected:  200
  Duration:  5s


  Thread Stats   Avg      p50      p90      p99    p99.9
    Latency   1.25ms    610us    997us   35.00ms   64.60ms

  10652871 requests in 5.00s, 10652622 responses
  Throughput: 2.13M req/s
  Bandwidth:  7.15GB/s
  Status codes: 2xx=10652622, 3xx=0, 4xx=0, 5xx=0
  Latency samples: 10652569 / 10652622 responses (100.0%)
  Reconnects: 425727
  Per-template: 1515724,1519305,1523251,1527013,1526505,1523199,1517572
  Per-template-ok: 1515724,1519305,1523251,1527013,1526505,1523199,1517572
[info] CPU 6507.2% | Mem 1.7GiB

[run 3/3]
gcannon v0.5.3
  Target:    localhost:8080/
  Threads:   64
  Conns:     4096 (64/thread)
  Pipeline:  1
  Req/conn:  25
  Templates: 7
  Expected:  200
  Duration:  5s


  Thread Stats   Avg      p50      p90      p99    p99.9
    Latency   1.25ms    601us    971us   36.60ms   65.20ms

  10647966 requests in 5.00s, 10647969 responses
  Throughput: 2.13M req/s
  Bandwidth:  7.15GB/s
  Status codes: 2xx=10647969, 3xx=0, 4xx=0, 5xx=0
  Latency samples: 10647883 / 10647969 responses (100.0%)
  Reconnects: 426170
  Per-template: 1515127,1519225,1522868,1526148,1526071,1522245,1516199
  Per-template-ok: 1515127,1519225,1522868,1526148,1526071,1522245,1516199
[info] CPU 6323.7% | Mem 1.7GiB

=== Best: 2131290 req/s (CPU: 6280.1%, Mem: 1.7GiB) ===
[info] input BW: 101.63MB/s (avg template: 50 bytes)
[info] saved results/json/4096/pico.json
httparena-bench-pico
httparena-bench-pico
[info] skip: pico does not subscribe to json-comp
[info] skip: pico does not subscribe to json-tls
[info] skip: pico does not subscribe to upload
[info] skip: pico does not subscribe to api-4
[info] skip: pico does not subscribe to api-16
[info] skip: pico does not subscribe to static
[info] skip: pico does not subscribe to async-db
[info] skip: pico does not subscribe to crud
[info] skip: pico does not subscribe to fortunes
[info] skip: pico does not subscribe to baseline-h2
[info] skip: pico does not subscribe to static-h2
[info] skip: pico does not subscribe to baseline-h2c
[info] skip: pico does not subscribe to json-h2c
[info] skip: pico does not subscribe to baseline-h3
[info] skip: pico does not subscribe to static-h3
[info] skip: pico does not subscribe to gateway-64
[info] skip: pico does not subscribe to gateway-h3
[info] skip: pico does not subscribe to production-stack
[info] skip: pico does not subscribe to unary-grpc
[info] skip: pico does not subscribe to unary-grpc-tls
[info] skip: pico does not subscribe to stream-grpc
[info] skip: pico does not subscribe to stream-grpc-tls
[info] skip: pico does not subscribe to echo-ws
[info] skip: pico does not subscribe to echo-ws-pipeline
[info] rebuilding site/data/*.json
[updated] /home/diogo/actions-runner/_work/HttpArena/HttpArena/site/data/frameworks.json
[updated] /home/diogo/actions-runner/_work/HttpArena/HttpArena/site/data/json-4096.json
[updated] /home/diogo/actions-runner/_work/HttpArena/HttpArena/site/data/pipelined-4096.json
[updated] /home/diogo/actions-runner/_work/HttpArena/HttpArena/site/data/pipelined-512.json
[updated] /home/diogo/actions-runner/_work/HttpArena/HttpArena/site/data/current.json
[info] done
[info] restoring loopback MTU to 65536