Metalゲームのパフォーマンス問題の検出と修正

5:00 - Collect a trace with metalperftrace

# Collect the last 5 hours
metalperftrace collect /tmp --last 5h

# Output
# Metal performance traces collected to: /tmp
# /tmp/MetalPerfTrace_20260401_094100_to_144100.atrc

# Or collect an explicit time range
metalperftrace collect /tmp \
  --start 2026-04-01T09:41:00 \
  --end 2026-04-01T12:41:00

7:02 - Print a trace overview

metalperftrace overview /Data/MyGameTrace.atrc

# [Modern Renderer pid:13833]
# Mem: 2146.1 MiB (2343.9 Peak, 1199.4 Metal)
# Total CPU Time: 2417.601s (33.17% Sys, 66.83% User)
# Instructions: 9944836683668 (5.75% P, 94.25% E)
# Cycles: 5176430469224 (4.45% P, 95.55% E)
# Disk Reads / Writes: 317.37 / 0.04 MiB (Logical Write 0.04)
# Layer 0x729293000 (3456x2104) Interval 300.065s Active 300.065s
#   59.7 FPS  17735 Frames  188 Skipped
#   Frame Time avg: 16.74ms min: 8.33 max: 125.00 stddev: 3.70
#   CPU Begin-to-Present avg: 3.99ms min: 1.40 max: 94.37 stddev: 1.80
#   On-GPU Time avg: 13.39ms min: 5.24 max: 37.57 stddev: 1.43
#   Next Drawable Wait avg: 0.26ms min: 0.00 max: 91.08 stddev: 1.75
#   Shader Compilation Time: 0.000s (Total: 0, Cached: 18)

7:58 - Filter by process and emit JSON

// Report state transitions
#import <StateReporting/StateReporting.h>

NSString *domain = @"com.mygame.level";
SRStateReporter *reporter = [SRStateReporter reporterForDomain:domain];

[reporter reportTransitionToStateLabel:@"Level 1"
                        stableMetadata:nil
                      volatileMetadata:nil];

[reporter reportTransitionToStateLabel:@"Level 1"
                        stableMetadata:@{ @"id": @1001 }
                      volatileMetadata:nil];

[reporter reportVolatileMetadataUpdate:@{ @"health": @100 }];

13:55 - Include full state transitions in overview

metalperftrace overview /Data/MyGameTrace.atrc --include-state-transitions

# [States]
# com.mygame.graphics
#   High (30.59%, 14.996s)  raytracing: 1  shadow: ultra
#   Medium (69.38%, 34.012s)  raytracing: 0  shadow: medium
# com.mygame.level
#   Level 1 (20.47%, 10.033s)  biome: forest   id: 1001
#   Level 2 (79.53%, 38.991s)  biome: volcano  id: 1002

14:15 - Aggregate metrics by state

# Aggregate across all domains / transitions
metalperftrace overview /Data/MyGameTrace.atrc --aggregate

# Aggregate one domain
metalperftrace overview /Data/MyGameTrace.atrc --aggregate \
  --domain com.mygame.graphics

# Aggregate a specific state label within a domain
metalperftrace overview /Data/MyGameTrace.atrc --aggregate \
  --domain com.mygame.graphics \
  --state-label "High"