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Speed up VM create with work seeds

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Beat VM create wall time without changing VM semantics.

Generate a work-seed ext4 sidecar during image builds and rootfs rebuilds, then clone and resize that seed for each new VM instead of rebuilding /root from scratch. Plumb the new seed artifact through config, runtime metadata, store state, runtime-bundle defaults, doctor checks, and default-image reconciliation so older images still fall back cleanly.

Add a daemon TAP pool to keep idle bridge-attached devices warm, expose stage timing in lifecycle logs, add a create/SSH benchmark script plus Make target, and teach verify.sh that tap-pool-* devices are reusable capacity rather than cleanup leaks.

Validated with go test ./..., make build, ./verify.sh, and make bench-create ARGS="--runs 2".
This commit is contained in:
Thales Maciel 2026-03-18 21:22:12 -03:00
parent a14a80fd6b
commit c8d9a122f9
No known key found for this signature in database
GPG key ID: 33112E6833C34679
24 changed files with 695 additions and 44 deletions
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12
internal/daemon/daemon.go
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@ -34,6 +34,9 @@ type Daemon struct {
mu sync.Mutex
vmLocksMu sync.Mutex
vmLocks map[string]*sync.Mutex
tapPoolMu sync.Mutex
tapPool []string
tapPoolNext int
closing chan struct{}
once sync.Once
pid int
@ -92,6 +95,11 @@ func Open(ctx context.Context) (d *Daemon, err error) {
d.logger.Error("daemon open failed", "stage", "reconcile", "error", err.Error())
return nil, err
}
if err = d.initializeTapPool(ctx); err != nil {
d.logger.Error("daemon open failed", "stage", "initialize_tap_pool", "error", err.Error())
return nil, err
}
go d.ensureTapPool(context.Background())
return d, nil
}
@ -436,7 +444,7 @@ func (d *Daemon) ensureDefaultImage(ctx context.Context) error {
return err
}
if d.logger != nil {
d.logger.Info("default image reconciled", append(imageLogAttrs(updated), "previous_rootfs_path", image.RootfsPath, "previous_kernel_path", image.KernelPath)...)
d.logger.Info("default image reconciled", append(imageLogAttrs(updated), "previous_rootfs_path", image.RootfsPath, "previous_work_seed_path", image.WorkSeedPath, "previous_kernel_path", image.KernelPath)...)
}
return nil
case errors.Is(err, sql.ErrNoRows):
@ -471,6 +479,7 @@ func (d *Daemon) desiredDefaultImage() (model.Image, bool) {
Managed: false,
ArtifactDir: "",
RootfsPath: rootfs,
WorkSeedPath: d.config.DefaultWorkSeed,
KernelPath: kernel,
InitrdPath: d.config.DefaultInitrd,
ModulesDir: d.config.DefaultModulesDir,
@ -484,6 +493,7 @@ func defaultImageMatches(current, desired model.Image) bool {
current.Managed == desired.Managed &&
current.ArtifactDir == desired.ArtifactDir &&
current.RootfsPath == desired.RootfsPath &&
current.WorkSeedPath == desired.WorkSeedPath &&
current.KernelPath == desired.KernelPath &&
current.InitrdPath == desired.InitrdPath &&
current.ModulesDir == desired.ModulesDir &&