feat(memlimit): handle default value of cgroup's memory limit

memlimit/cgroups_linux.go

@@ -4,6 +4,8 @@
 package memlimit
 
 import (
+	"math"
+	"os"
 	"path/filepath"
 
 	"github.com/containerd/cgroups/v3"
@@ -42,13 +44,18 @@ func FromCgroupV1() (uint64, error) {
 		return 0, err
 	}
 
-	if limit := metrics.GetMemory().GetHierarchicalMemoryLimit(); limit != 0 {
+	if limit := metrics.GetMemory().GetHierarchicalMemoryLimit(); limit != 0 && limit != getCgroupV1NoLimit() {
 		return limit, nil
 	}
 
 	return 0, ErrNoLimit
 }
 
+func getCgroupV1NoLimit() uint64 {
+	ps := uint64(os.Getpagesize())
+	return math.MaxInt64 / ps * ps
+}
+
 // FromCgroupHybrid returns the memory limit from the cgroup v1 or v2.
 // It checks the cgroup v2 first, and if it fails, it falls back to cgroup v1.
 func FromCgroupHybrid() (uint64, error) {
@@ -83,7 +90,7 @@ func fromCgroupV2(mountPoint string) (uint64, error) {
 		return 0, err
 	}
 
-	if limit := stats.GetMemory().GetUsageLimit(); limit != 0 {
+	if limit := stats.GetMemory().GetUsageLimit(); limit != 0 && limit != math.MaxUint64 {
 		return limit, nil
 	}
 

memlimit/memlimit.go

@@ -133,6 +133,10 @@ func SetGoMemLimitWithOpts(opts ...Option) (_ int64, _err error) {
 
 	limit, err := setGoMemLimit(ApplyRatio(cfg.provider, ratio))
 	if err != nil {
+		if errors.Is(err, ErrNoLimit) {
+			cfg.logger.Printf("memory is not limited, skipping: %v\n", err)
+			return 0, nil
+		}
 		return 0, fmt.Errorf("failed to set GOMEMLIMIT: %w", err)
 	}