fix: limit no data in fd log messages

Author: dobrac

…ernal/sandbox/uffd/userfaultfd/eagain.go …box/uffd/userfaultfd/counter_reporter.gopackages/orchestrator/internal/sandbox/uffd/userfaultfd/eagain.go renamed to packages/orchestrator/internal/sandbox/uffd/userfaultfd/counter_reporter.go packages/orchestrator/internal/sandbox/uffd/userfaultfd/eagain.go renamed to packages/orchestrator/internal/sandbox/uffd/userfaultfd/counter_reporter.go

@@ -9,16 +9,16 @@ import (
 	"github.com/e2b-dev/infra/packages/shared/pkg/logger"
 )
 
-type eagainCounter struct {
+type counterReporter struct {
 	count     uint64
 	startTime time.Time
 	endTime   time.Time
 	logger    logger.Logger
 	msg       string
 }
 
-func newEagainCounter(logger logger.Logger, msg string) *eagainCounter {
-	return &eagainCounter{
+func newCounterReporter(logger logger.Logger, msg string) *counterReporter {
+	return &counterReporter{
 		count:     0,
 		startTime: time.Time{},
 		endTime:   time.Time{},
@@ -27,7 +27,7 @@ func newEagainCounter(logger logger.Logger, msg string) *eagainCounter {
 	}
 }
 
-func (c *eagainCounter) Increase() {
+func (c *counterReporter) Increase() {
 	if c.count == 0 {
 		c.startTime = time.Now()
 	}
@@ -37,7 +37,7 @@ func (c *eagainCounter) Increase() {
 	c.endTime = time.Now()
 }
 
-func (c *eagainCounter) log(ctx context.Context, closing bool) {
+func (c *counterReporter) log(ctx context.Context, closing bool) {
 	if c.count > 0 {
 		c.logger.Debug(ctx,
 			c.msg,
@@ -51,10 +51,10 @@ func (c *eagainCounter) log(ctx context.Context, closing bool) {
 	}
 }
 
-func (c *eagainCounter) Close(ctx context.Context) {
+func (c *counterReporter) Close(ctx context.Context) {
 	c.log(ctx, true)
 }
 
-func (c *eagainCounter) Log(ctx context.Context) {
+func (c *counterReporter) Log(ctx context.Context) {
 	c.log(ctx, false)
 }

packages/orchestrator/internal/sandbox/uffd/userfaultfd/userfaultfd.go

@@ -86,9 +86,12 @@ func (u *Userfaultfd) Serve(
 		{Fd: fdExit.Reader(), Events: unix.POLLIN},
 	}
 
-	eagainCounter := newEagainCounter(u.logger, "uffd: eagain during fd read (accumulated)")
+	eagainCounter := newCounterReporter(u.logger, "uffd: eagain during fd read (accumulated)")
 	defer eagainCounter.Close(ctx)
 
+	noDataCounter := newCounterReporter(u.logger, "uffd: no data in fd (accumulated)")
+	defer noDataCounter.Close(ctx)
+
 outerLoop:
 	for {
 		if _, err := unix.Poll(
@@ -135,7 +138,7 @@ outerLoop:
 			// - https://man7.org/linux/man-pages/man2/userfaultfd.2.html
 			// It might be possible to just check for data != 0 in the syscall.Read loop
 			// but I don't feel confident about doing that.
-			u.logger.Debug(ctx, "uffd: no data in fd, going back to polling")
+			noDataCounter.Increase()
 
 			continue
 		}
@@ -154,6 +157,7 @@ outerLoop:
 				// There is no error so we can proceed.
 
 				eagainCounter.Log(ctx)
+				noDataCounter.Log(ctx)
 
 				break
 			}