fix(f3): fix hot loop in F3 participation

Signed-off-by: Jakub Sztandera <[email protected]>

CHANGELOG.md

@@ -18,6 +18,7 @@
 - Update `EthGetBlockByNumber` to return a pointer to ethtypes.EthBlock or nil for null rounds. ([filecoin-project/lotus#12529](https://github.com/filecoin-project/lotus/pull/12529))
 - Reduce size of embedded genesis CAR files by removing WASM actor blocks and compressing with zstd. This reduces the `lotus` binary size by approximately 10 MiB. ([filecoin-project/lotus#12439](https://github.com/filecoin-project/lotus/pull/12439))
 - Add ChainSafe operated Calibration archival node to the bootstrap list ([filecoin-project/lotus#12517](https://github.com/filecoin-project/lotus/pull/12517))
+- Fix hotloop in F3 pariticpation API ([filecoin-project/lotus#12575](https://github.com/filecoin-project/lotus/pull/12575))
 
 ## Bug Fixes
 

node/modules/storageminer.go

@@ -380,15 +380,28 @@ func newF3Participator(node v1api.FullNode, participant dtypes.MinerAddress, bac
 
 func (p *f3Participator) participate(ctx context.Context) error {
 	for ctx.Err() == nil {
-		if ticket, err := p.tryGetF3ParticipationTicket(ctx); err != nil {
-			return err
-		} else if lease, participating, err := p.tryF3Participate(ctx, ticket); err != nil {
+		start := time.Now()
+		ticket, err := p.tryGetF3ParticipationTicket(ctx)
+		if err != nil {
 			return err
-		} else if !participating {
-			continue
-		} else if err := p.awaitLeaseExpiry(ctx, lease); err != nil {
+		}
+		lease, participating, err := p.tryF3Participate(ctx, ticket)
+		if err != nil {
 			return err
 		}
+		if participating {
+			if err := p.awaitLeaseExpiry(ctx, lease); err != nil {
+				return err
+			}
+		}
+		const minPeriod = 500 * time.Millisecond
+		if sinceLastLoop := time.Since(start); sinceLastLoop < minPeriod {
+			select {
+			case <-time.After(minPeriod - sinceLastLoop):
+			case <-ctx.Done():
+				return ctx.Err()
+			}
+		}
 		log.Info("Restarting F3 participation")
 	}
 	return ctx.Err()
@@ -485,8 +498,8 @@ func (p *f3Participator) awaitLeaseExpiry(ctx context.Context, lease api.F3Parti
 			}
 			log.Errorw("Failed to check F3 progress while awaiting lease expiry. Retrying after backoff.", "attempts", p.backoff.Attempt(), "backoff", p.backoff.Duration(), "err", err)
 			p.backOff(ctx)
-		case progress.ID+2 >= lease.ValidityTerm:
-			log.Infof("F3 progressed (%d) to within two instances of lease expiry (%d). Restarting participation.", progress.ID, lease.ValidityTerm)
+		case progress.ID+2 >= lease.FromInstance+lease.ValidityTerm:
+			log.Infof("F3 progressed (%d) to within two instances of lease expiry (%d+%d). Restarting participation.", progress.ID, lease.FromInstance, lease.ValidityTerm)
 			return nil
 		default:
 			remainingInstanceLease := lease.ValidityTerm - progress.ID