Fix RAM usage calculation error (#6412)

src/Controller/Api/Admin/ServerStatsAction.php

@@ -150,14 +150,20 @@ final class ServerStatsAction implements SingleActionInterface
                 'bytes' => [
                     'total' => $memoryStats->memTotal,
                     'free' => $memoryStats->memFree,
-                    'cached' => $memoryStats->cached,
+                    'buffers' => $memoryStats->buffers,
+                    'cached' => $memoryStats->getCachedMemory(),
+                    'sReclaimable' => $memoryStats->sReclaimable,
+                    'shmem' => $memoryStats->shmem,
                     'used' => $memoryStats->getUsedMemory(),
                 ],
                 'readable' => [
-                    'total' => Quota::getReadableSize($memoryStats->memTotal),
-                    'free' => Quota::getReadableSize($memoryStats->memFree),
-                    'cached' => Quota::getReadableSize($memoryStats->cached),
-                    'used' => Quota::getReadableSize($memoryStats->getUsedMemory()),
+                    'total' => Quota::getReadableSize($memoryStats->memTotal, 2),
+                    'free' => Quota::getReadableSize($memoryStats->memFree, 2),
+                    'buffers' => Quota::getReadableSize($memoryStats->buffers, 2),
+                    'cached' => Quota::getReadableSize($memoryStats->getCachedMemory(), 2),
+                    'sReclaimable' => Quota::getReadableSize($memoryStats->sReclaimable, 2),
+                    'shmem' => Quota::getReadableSize($memoryStats->shmem, 2),
+                    'used' => Quota::getReadableSize($memoryStats->getUsedMemory(), 2),
                 ],
             ],
             'swap' => [
@@ -167,9 +173,9 @@ final class ServerStatsAction implements SingleActionInterface
                     'used' => $memoryStats->getUsedSwap(),
                 ],
                 'readable' => [
-                    'total' => Quota::getReadableSize($memoryStats->swapTotal),
-                    'free' => Quota::getReadableSize($memoryStats->swapFree),
-                    'used' => Quota::getReadableSize($memoryStats->getUsedSwap()),
+                    'total' => Quota::getReadableSize($memoryStats->swapTotal, 2),
+                    'free' => Quota::getReadableSize($memoryStats->swapFree, 2),
+                    'used' => Quota::getReadableSize($memoryStats->getUsedSwap(), 2),
                 ],
             ],
             'disk' => [

src/Radio/Quota.php

@@ -31,7 +31,7 @@ final class Quota
         $factor = (int)floor((strlen($bytesStr) - 1) / 3);
 
         if (isset($size[$factor])) {
-            $byteDivisor = Math\BigInteger::of(1000)->power($factor);
+            $byteDivisor = Math\BigInteger::of(1024)->power($factor);
             $sizeString = $bytes->toBigDecimal()
                 ->dividedBy($byteDivisor, $decimals, Math\RoundingMode::HALF_DOWN);
 
@@ -66,7 +66,7 @@ final class Quota
                 haystack: 'bkmgtpezy',
                 needle: $unit[0]
             ) ?: 0;
-            $byteMultiplier = Math\BigInteger::of(1000)->power($bytePower);
+            $byteMultiplier = Math\BigInteger::of(1024)->power($bytePower);
 
             return Math\BigDecimal::of($size)
                 ->multipliedBy($byteMultiplier)

src/Service/MemoryStats/MemoryData.php

@@ -12,7 +12,10 @@ final class MemoryData
     public function __construct(
         public readonly BigInteger $memTotal,
         public readonly BigInteger $memFree,
+        public readonly BigInteger $buffers,
         public readonly BigInteger $cached,
+        public readonly BigInteger $sReclaimable,
+        public readonly BigInteger $shmem,
         public readonly BigInteger $swapTotal,
         public readonly BigInteger $swapFree,
     ) {
@@ -22,14 +25,20 @@ final class MemoryData
     {
         $memTotal = Quota::convertFromReadableSize($meminfo['MemTotal']) ?? BigInteger::zero();
         $memFree = Quota::convertFromReadableSize($meminfo['MemFree']) ?? BigInteger::zero();
+        $buffers = Quota::convertFromReadableSize($meminfo['Buffers']) ?? BigInteger::zero();
         $cached = Quota::convertFromReadableSize($meminfo['Cached']) ?? BigInteger::zero();
+        $sReclaimable = Quota::convertFromReadableSize($meminfo['SReclaimable']) ?? BigInteger::zero();
+        $shmem = Quota::convertFromReadableSize($meminfo['Shmem']) ?? BigInteger::zero();
         $swapTotal = Quota::convertFromReadableSize($meminfo['SwapTotal']) ?? BigInteger::zero();
         $swapFree = Quota::convertFromReadableSize($meminfo['SwapFree']) ?? BigInteger::zero();
 
         return new self(
             $memTotal,
             $memFree,
+            $buffers,
             $cached,
+            $sReclaimable,
+            $shmem,
             $swapTotal,
             $swapFree
         );
@@ -37,9 +46,20 @@ final class MemoryData
 
     public function getUsedMemory(): BigInteger
     {
-        return $this->memTotal
-            ->minus($this->memFree)
-            ->minus($this->cached);
+        $usedDiff = $this->memFree
+            ->plus($this->cached)
+            ->plus($this->sReclaimable)
+            ->minus($this->shmem)
+            ->plus($this->buffers);
+
+        return $this->memTotal->isGreaterThanOrEqualTo($usedDiff)
+            ? $this->memTotal->minus($usedDiff)
+            : $this->memTotal->minus($this->memFree);
+    }
+
+    public function getCachedMemory(): BigInteger
+    {
+        return $this->cached->plus($this->buffers);
     }
 
     public function getUsedSwap(): BigInteger