Remove KernelMemory option from /containers/create and /update endpoints

- remove KernelMemory option from `v1.42` api docs
 - remove KernelMemory warning on `/info`
 - update changes for `v1.42`
 - remove `KernelMemory` field from endpoints docs

Signed-off-by: aiordache <anca.iordache@docker.com>
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

api/server/router/container/container_routes.go

@@ -439,6 +439,12 @@ func (s *containerRouter) postContainerUpdate(ctx context.Context, w http.Respon
 	if versions.LessThan(httputils.VersionFromContext(ctx), "1.40") {
 		updateConfig.PidsLimit = nil
 	}
+
+	if versions.GreaterThanOrEqualTo(httputils.VersionFromContext(ctx), "1.42") {
+		// Ignore KernelMemory removed in API 1.42.
+		updateConfig.KernelMemory = 0
+	}
+
 	if updateConfig.PidsLimit != nil && *updateConfig.PidsLimit <= 0 {
 		// Both `0` and `-1` are accepted to set "unlimited" when updating.
 		// Historically, any negative value was accepted, so treat them as
@@ -505,6 +511,11 @@ func (s *containerRouter) postContainersCreate(ctx context.Context, w http.Respo
 		}
 	}
 
+	if hostConfig != nil && versions.GreaterThanOrEqualTo(version, "1.42") {
+		// Ignore KernelMemory removed in API 1.42.
+		hostConfig.KernelMemory = 0
+	}
+
 	var platform *specs.Platform
 	if versions.GreaterThanOrEqualTo(version, "1.41") {
 		if v := r.Form.Get("platform"); v != "" {

api/swagger.yaml

@@ -577,17 +577,6 @@ definitions:
         type: "array"
         items:
           $ref: "#/definitions/DeviceRequest"
-      KernelMemory:
-        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
       KernelMemoryTCP:
         description: "Hard limit for kernel TCP buffer memory (in bytes)."
         type: "integer"
@@ -4657,16 +4646,6 @@ definitions:
         description: "Indicates if the host has memory swap limit support enabled."
         type: "boolean"
         example: true
-      KernelMemory:
-        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
       KernelMemoryTCP:
         description: |
           Indicates if the host has kernel memory TCP limit support enabled.
@@ -5834,7 +5813,6 @@ paths:
                 Memory: 0
                 MemorySwap: 0
                 MemoryReservation: 0
-                KernelMemory: 0
                 NanoCpus: 500000
                 CpuPercent: 80
                 CpuShares: 512
@@ -6126,7 +6104,6 @@ paths:
                 Memory: 0
                 MemorySwap: 0
                 MemoryReservation: 0
-                KernelMemory: 0
                 OomKillDisable: false
                 OomScoreAdj: 500
                 NetworkMode: "bridge"
@@ -6871,7 +6848,6 @@ paths:
               Memory: 314572800
               MemorySwap: 514288000
               MemoryReservation: 209715200
-              KernelMemory: 52428800
               RestartPolicy:
                 MaximumRetryCount: 4
                 Name: "on-failure"

daemon/daemon_unix.go

@@ -445,17 +445,16 @@ func verifyPlatformContainerResources(resources *containertypes.Resources, sysIn
 		// 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
-	}
-	if resources.KernelMemory > 0 && resources.KernelMemory < linuxMinMemory {
-		return warnings, fmt.Errorf("Minimum kernel memory limit allowed is 6MB")
-	}
-	if resources.KernelMemory > 0 && !kernel.CheckKernelVersion(4, 0, 0) {
-		warnings = append(warnings, "You specified a kernel memory limit on a kernel older than 4.0. Kernel memory limits are experimental on older kernels, it won't work as expected and can cause your system to be unstable.")
+		if !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
+		}
+		if resources.KernelMemory < linuxMinMemory {
+			return warnings, fmt.Errorf("Minimum kernel memory limit allowed is 6MB")
+		}
+		if !kernel.CheckKernelVersion(4, 0, 0) {
+			warnings = append(warnings, "You specified a kernel memory limit on a kernel older than 4.0. Kernel memory limits are experimental on older kernels, it won't work as expected and can cause your system to be unstable.")
+		}
 	}
 	if resources.OomKillDisable != nil && !sysInfo.OomKillDisable {
 		// only produce warnings if the setting wasn't to *disable* the OOM Kill; no point

docs/api/version-history.md

@@ -42,6 +42,9 @@ keywords: "API, Docker, rcli, REST, documentation"
   versioned, and affects all API versions if the daemon has this patch.
 * The `POST /containers/{id}/wait` endpoint now returns a `400` status code if an
   invalid `condition` is provided (on API 1.30 and up).
+* Removed the `KernelMemory` field from the `POST /containers/create` and
+  `POST /containers/{id}/update` endpoints, any value it is set to will be ignored.
+  This field has been deprecated in `v1.41`.
 
 ## v1.41 API changes
 

pkg/sysinfo/sysinfo_linux.go

@@ -149,10 +149,6 @@ func applyMemoryCgroupInfo(info *SysInfo) {
 	if !info.MemorySwappiness {
 		info.Warnings = append(info.Warnings, "Your kernel does not support memory swappiness")
 	}
-	info.KernelMemory = cgroupEnabled(mountPoint, "memory.kmem.limit_in_bytes")
-	if !info.KernelMemory {
-		info.Warnings = append(info.Warnings, "Your kernel does not support kernel memory limit")
-	}
 	info.KernelMemoryTCP = cgroupEnabled(mountPoint, "memory.kmem.tcp.limit_in_bytes")
 	if !info.KernelMemoryTCP {
 		info.Warnings = append(info.Warnings, "Your kernel does not support kernel memory TCP limit")