fix: get rid of large buffers (#19549)

these lead to run-away usage of memory
beyond which the Go's GC can handle, we
have to re-visit this differently, remove
this for now.

cmd/xl-storage.go

@@ -2124,14 +2124,6 @@ func (s *xlStorage) writeAllDirect(ctx context.Context, filePath string, fileSiz
 
 	var bufp *[]byte
 	switch {
-	case fileSize > 0 && fileSize >= xioutil.XXLargeBlock*2:
-		// use a larger 8MiB buffer for a really really large streamsx.
-		bufp = xioutil.ODirectPoolXXLarge.Get().(*[]byte)
-		defer xioutil.ODirectPoolXXLarge.Put(bufp)
-	case fileSize > 0 && fileSize >= xioutil.XLargeBlock:
-		// use a larger 4MiB buffer for a really large streams.
-		bufp = xioutil.ODirectPoolXLarge.Get().(*[]byte)
-		defer xioutil.ODirectPoolXLarge.Put(bufp)
 	case fileSize <= xioutil.SmallBlock:
 		bufp = xioutil.ODirectPoolSmall.Get().(*[]byte)
 		defer xioutil.ODirectPoolSmall.Put(bufp)

internal/ioutil/ioutil.go

@@ -34,26 +34,12 @@ import (
 
 // Block sizes constant.
 const (
-	SmallBlock   = 32 * humanize.KiByte // Default r/w block size for smaller objects.
+	SmallBlock = 32 * humanize.KiByte // Default r/w block size for smaller objects.
-	LargeBlock   = 1 * humanize.MiByte  // Default r/w block size for normal objects.
+	LargeBlock = 1 * humanize.MiByte  // Default r/w block size for normal objects.
-	XLargeBlock  = 4 * humanize.MiByte  // Default r/w block size for very large objects.
-	XXLargeBlock = 8 * humanize.MiByte  // Default r/w block size for very very large objects.
 )
 
 // aligned sync.Pool's
 var (
-	ODirectPoolXXLarge = sync.Pool{
-		New: func() interface{} {
-			b := disk.AlignedBlock(XXLargeBlock)
-			return &b
-		},
-	}
-	ODirectPoolXLarge = sync.Pool{
-		New: func() interface{} {
-			b := disk.AlignedBlock(XLargeBlock)
-			return &b
-		},
-	}
 	ODirectPoolLarge = sync.Pool{
 		New: func() interface{} {
 			b := disk.AlignedBlock(LargeBlock)