@@ -528,7 +528,13 @@ definitions:

         items:

           $ref: "#/definitions/DeviceRequest"

       KernelMemory:

-        description: "Kernel memory limit in bytes."

+        description: |

+          Kernel memory limit in bytes.

+

+          <p><br /></p>

+

+          > **Deprecated**: This field is deprecated as the kernel 5.4 deprecated

+          > `kmem.limit_in_bytes`.

         type: "integer"

         format: "int64"

         example: 209715200

@@ -4321,7 +4327,13 @@ definitions:

         type: "boolean"

         example: true

       KernelMemory:

-        description: "Indicates if the host has kernel memory limit support enabled."

+        description: |

+          Indicates if the host has kernel memory limit support enabled.

+

+          <p><br /></p>

+

+          > **Deprecated**: This field is deprecated as the kernel 5.4 deprecated

+          > `kmem.limit_in_bytes`.

         type: "boolean"

         example: true

       CpuCfsPeriod:

@@ -361,7 +361,7 @@ type Resources struct {

 	Devices              []DeviceMapping // List of devices to map inside the container

 	DeviceCgroupRules    []string        // List of rule to be added to the device cgroup

 	DeviceRequests       []DeviceRequest // List of device requests for device drivers

-	KernelMemory         int64           // Kernel memory limit (in bytes)

+	KernelMemory         int64           // Kernel memory limit (in bytes), Deprecated: kernel 5.4 deprecated kmem.limit_in_bytes

 	KernelMemoryTCP      int64           // Hard limit for kernel TCP buffer memory (in bytes)

 	MemoryReservation    int64           // Memory soft limit (in bytes)

 	MemorySwap           int64           // Total memory usage (memory + swap); set `-1` to enable unlimited swap

@@ -158,7 +158,7 @@ type Info struct {

 	Plugins            PluginsInfo

 	MemoryLimit        bool

 	SwapLimit          bool

-	KernelMemory       bool

+	KernelMemory       bool // Deprecated: kernel 5.4 deprecated kmem.limit_in_bytes

 	KernelMemoryTCP    bool

 	CPUCfsPeriod       bool `json:"CpuCfsPeriod"`

 	CPUCfsQuota        bool `json:"CpuCfsQuota"`

@@ -465,6 +465,12 @@ func verifyPlatformContainerResources(resources *containertypes.Resources, sysIn

 	if resources.Memory > 0 && resources.MemoryReservation > 0 && resources.Memory < resources.MemoryReservation {

 		return warnings, fmt.Errorf("Minimum memory limit can not be less than memory reservation limit, see usage")

 	}

+	if resources.KernelMemory > 0 {

+		// Kernel memory limit is not supported on cgroup v2.

+		// Even on cgroup v1, kernel memory limit (`kmem.limit_in_bytes`) has been deprecated since kernel 5.4.

+		// https://github.com/torvalds/linux/commit/0158115f702b0ba208ab0b5adf44cae99b3ebcc7

+		warnings = append(warnings, "Specifying a kernel memory limit is deprecated and will be removed in a future release.")

+	}

 	if resources.KernelMemory > 0 && !sysInfo.KernelMemory {

 		warnings = append(warnings, "Your kernel does not support kernel memory limit capabilities or the cgroup is not mounted. Limitation discarded.")

 		resources.KernelMemory = 0

@@ -100,9 +100,6 @@ func (daemon *Daemon) fillPlatformInfo(v *types.Info, sysInfo *sysinfo.SysInfo)

 		if !v.SwapLimit {

 			v.Warnings = append(v.Warnings, "WARNING: No swap limit support")

 		}

-		if !v.KernelMemory {

-			v.Warnings = append(v.Warnings, "WARNING: No kernel memory limit support")

-		}

 		if !v.KernelMemoryTCP {

 			v.Warnings = append(v.Warnings, "WARNING: No kernel memory TCP limit support")

 		}

@@ -74,6 +74,8 @@ keywords: "API, Docker, rcli, REST, documentation"

   job-mode service.

 * `GET /containers/{id}/stats` now accepts a query param (`one-shot`) which, when used with `stream=false` fetches a

   single set of stats instead of waiting for two collection cycles to have 2 CPU stats over a 1 second period.

+* The `KernelMemory` field in `HostConfig.Resources` is now deprecated.

+* The `KernelMemory` field in `Info` is now deprecated.

 ## v1.40 API changes