Fix calculation of memory usage prediction for mmap mode (#26264)

Signed-off-by: Nyah01 <yah2er0ne@outlook.com>

internal/core/src/mmap/Column.h

@@ -30,11 +30,7 @@
 
 namespace milvus {
 
-#ifdef MAP_POPULATE
-static int mmap_flags = MAP_SHARED | MAP_POPULATE;
-#else
 static int mmap_flags = MAP_SHARED;
-#endif
 
 class ColumnBase {
  public:

internal/querynodev2/segments/segment_loader.go

@@ -299,6 +299,13 @@ func (loader *segmentLoader) notifyLoadFinish(segments ...*querypb.SegmentLoadIn
 // requestResource requests memory & storage to load segments,
 // returns the memory usage, disk usage and concurrency with the gained memory.
 func (loader *segmentLoader) requestResource(ctx context.Context, infos ...*querypb.SegmentLoadInfo) (LoadResource, int, error) {
+	segmentIDs := lo.Map(infos, func(info *querypb.SegmentLoadInfo, _ int) int64 {
+		return info.GetSegmentID()
+	})
+	log := log.Ctx(ctx).With(
+		zap.Int64s("segmentIDs", segmentIDs),
+	)
+
 	resource := LoadResource{}
 
 	loader.mut.Lock()
@@ -350,6 +357,14 @@ func (loader *segmentLoader) requestResource(ctx context.Context, infos ...*quer
 	resource.DiskSize += du
 
 	loader.committedResource.Add(resource)
+	log.Info("request resource for loading segments",
+		zap.Int("workerNum", resource.WorkNum),
+		zap.Int("committedWorkerNum", loader.committedResource.WorkNum),
+		zap.Uint64("memory", resource.MemorySize),
+		zap.Uint64("committedMemory", loader.committedResource.MemorySize),
+		zap.Uint64("disk", resource.DiskSize),
+		zap.Uint64("committedDisk", loader.committedResource.DiskSize),
+	)
 
 	return resource, concurrencyLevel, nil
 }
@@ -830,6 +845,7 @@ func (loader *segmentLoader) checkSegmentSize(ctx context.Context, segmentLoadIn
 	metrics.QueryNodeDiskUsedSize.WithLabelValues(fmt.Sprint(paramtable.GetNodeID())).Set(float64(toMB(uint64(localDiskUsage))))
 	diskUsage := uint64(localDiskUsage) + loader.committedResource.DiskSize
 
+	mmapEnabled := len(paramtable.Get().QueryNodeCfg.MmapDirPath.GetValue()) > 0
 	maxSegmentSize := uint64(0)
 	predictMemUsage := memUsage
 	predictDiskUsage := diskUsage
@@ -856,10 +872,18 @@ func (loader *segmentLoader) checkSegmentSize(ctx context.Context, segmentLoadIn
 					)
 					return 0, 0, err
 				}
-				predictMemUsage += neededMemSize
-				predictDiskUsage += neededDiskSize
+				if mmapEnabled {
+					predictDiskUsage += neededMemSize + neededDiskSize
+				} else {
+					predictMemUsage += neededMemSize
+					predictDiskUsage += neededDiskSize
+				}
 			} else {
-				predictMemUsage += uint64(getBinlogDataSize(fieldBinlog))
+				if mmapEnabled {
+					predictDiskUsage += uint64(getBinlogDataSize(fieldBinlog))
+				} else {
+					predictMemUsage += uint64(getBinlogDataSize(fieldBinlog))
+				}
 			}
 		}
 
@@ -878,7 +902,6 @@ func (loader *segmentLoader) checkSegmentSize(ctx context.Context, segmentLoadIn
 		}
 	}
 
-	mmapEnabled := len(paramtable.Get().QueryNodeCfg.MmapDirPath.GetValue()) > 0
 	log.Info("predict memory and disk usage while loading (in MiB)",
 		zap.Uint64("maxSegmentSize", toMB(maxSegmentSize)),
 		zap.Int("concurrency", concurrency),