1 files changed, 77 insertions, 0 deletions
diff --git a/pkg/sentry/fsimpl/proc/meminfo.go b/pkg/sentry/fsimpl/proc/meminfo.go
new file mode 100644
index 000000000..9a827cd66
--- /dev/null
+++ b/pkg/sentry/fsimpl/proc/meminfo.go
@@ -0,0 +1,77 @@
+// Copyright 2019 The gVisor Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package proc
+
+import (
+	"bytes"
+	"fmt"
+
+	"gvisor.dev/gvisor/pkg/sentry/context"
+	"gvisor.dev/gvisor/pkg/sentry/kernel"
+	"gvisor.dev/gvisor/pkg/sentry/usage"
+	"gvisor.dev/gvisor/pkg/sentry/usermem"
+	"gvisor.dev/gvisor/pkg/sentry/vfs"
+)
+
+// meminfoData implements vfs.DynamicBytesSource for /proc/meminfo.
+//
+// +stateify savable
+type meminfoData struct {
+	// k is the owning Kernel.
+	k *kernel.Kernel
+}
+
+var _ vfs.DynamicBytesSource = (*meminfoData)(nil)
+
+// Generate implements vfs.DynamicBytesSource.Generate.
+func (d *meminfoData) Generate(ctx context.Context, buf *bytes.Buffer) error {
+	mf := d.k.MemoryFile()
+	mf.UpdateUsage()
+	snapshot, totalUsage := usage.MemoryAccounting.Copy()
+	totalSize := usage.TotalMemory(mf.TotalSize(), totalUsage)
+	anon := snapshot.Anonymous + snapshot.Tmpfs
+	file := snapshot.PageCache + snapshot.Mapped
+	// We don't actually have active/inactive LRUs, so just make up numbers.
+	activeFile := (file / 2) &^ (usermem.PageSize - 1)
+	inactiveFile := file - activeFile
+
+	fmt.Fprintf(buf, "MemTotal:       %8d kB\n", totalSize/1024)
+	memFree := (totalSize - totalUsage) / 1024
+	// We use MemFree as MemAvailable because we don't swap.
+	// TODO(rahat): When reclaim is implemented the value of MemAvailable
+	// should change.
+	fmt.Fprintf(buf, "MemFree:        %8d kB\n", memFree)
+	fmt.Fprintf(buf, "MemAvailable:   %8d kB\n", memFree)
+	fmt.Fprintf(buf, "Buffers:               0 kB\n") // memory usage by block devices
+	fmt.Fprintf(buf, "Cached:         %8d kB\n", (file+snapshot.Tmpfs)/1024)
+	// Emulate a system with no swap, which disables inactivation of anon pages.
+	fmt.Fprintf(buf, "SwapCache:             0 kB\n")
+	fmt.Fprintf(buf, "Active:         %8d kB\n", (anon+activeFile)/1024)
+	fmt.Fprintf(buf, "Inactive:       %8d kB\n", inactiveFile/1024)
+	fmt.Fprintf(buf, "Active(anon):   %8d kB\n", anon/1024)
+	fmt.Fprintf(buf, "Inactive(anon):        0 kB\n")
+	fmt.Fprintf(buf, "Active(file):   %8d kB\n", activeFile/1024)
+	fmt.Fprintf(buf, "Inactive(file): %8d kB\n", inactiveFile/1024)
+	fmt.Fprintf(buf, "Unevictable:           0 kB\n") // TODO(b/31823263)
+	fmt.Fprintf(buf, "Mlocked:               0 kB\n") // TODO(b/31823263)
+	fmt.Fprintf(buf, "SwapTotal:             0 kB\n")
+	fmt.Fprintf(buf, "SwapFree:              0 kB\n")
+	fmt.Fprintf(buf, "Dirty:                 0 kB\n")
+	fmt.Fprintf(buf, "Writeback:             0 kB\n")
+	fmt.Fprintf(buf, "AnonPages:      %8d kB\n", anon/1024)
+	fmt.Fprintf(buf, "Mapped:         %8d kB\n", file/1024) // doesn't count mapped tmpfs, which we don't know
+	fmt.Fprintf(buf, "Shmem:          %8d kB\n", snapshot.Tmpfs/1024)
+	return nil
+}