diff options
Diffstat (limited to 'pkg')
| -rw-r--r-- | pkg/sentry/control/BUILD | 2 | ||||
| -rw-r--r-- | pkg/sentry/control/usage.go | 183 |
2 files changed, 185 insertions, 0 deletions
diff --git a/pkg/sentry/control/BUILD b/pkg/sentry/control/BUILD index 7ee237c9f..fa3fe47c1 100644 --- a/pkg/sentry/control/BUILD +++ b/pkg/sentry/control/BUILD @@ -12,6 +12,7 @@ go_library( "pprof.go", "proc.go", "state.go", + "usage.go", ], visibility = [ "//:sandbox", @@ -39,6 +40,7 @@ go_library( "//pkg/tcpip/link/sniffer", "//pkg/urpc", "//pkg/usermem", + "@org_golang_x_sys//unix:go_default_library", ], ) diff --git a/pkg/sentry/control/usage.go b/pkg/sentry/control/usage.go new file mode 100644 index 000000000..cc78d3f45 --- /dev/null +++ b/pkg/sentry/control/usage.go @@ -0,0 +1,183 @@ +// Copyright 2021 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 control + +import ( + "fmt" + "os" + "runtime" + + "golang.org/x/sys/unix" + "gvisor.dev/gvisor/pkg/sentry/kernel" + "gvisor.dev/gvisor/pkg/sentry/usage" + "gvisor.dev/gvisor/pkg/urpc" +) + +// Usage includes usage-related RPC stubs. +type Usage struct { + Kernel *kernel.Kernel +} + +// MemoryUsageOpts contains usage options. +type MemoryUsageOpts struct { + // Full indicates that a full accounting should be done. If Full is not + // specified, then a partial accounting will be done, and Unknown will + // contain a majority of memory. See Collect for more information. + Full bool `json:"Full"` +} + +// MemoryUsage is a memory usage structure. +type MemoryUsage struct { + Unknown uint64 `json:"Unknown"` + System uint64 `json:"System"` + Anonymous uint64 `json:"Anonymous"` + PageCache uint64 `json:"PageCache"` + Mapped uint64 `json:"Mapped"` + Tmpfs uint64 `json:"Tmpfs"` + Ramdiskfs uint64 `json:"Ramdiskfs"` + Total uint64 `json:"Total"` +} + +// MemoryUsageFileOpts contains usage file options. +type MemoryUsageFileOpts struct { + // Version is used to ensure both sides agree on the format of the + // shared memory buffer. + Version uint64 `json:"Version"` +} + +// MemoryUsageFile contains the file handle to the usage file. +type MemoryUsageFile struct { + urpc.FilePayload +} + +// UsageFD returns the file that tracks the memory usage of the application. +func (u *Usage) UsageFD(opts *MemoryUsageFileOpts, out *MemoryUsageFile) error { + // Only support version 1 for now. + if opts.Version != 1 { + return fmt.Errorf("unsupported version requested: %d", opts.Version) + } + + mf := u.Kernel.MemoryFile() + *out = MemoryUsageFile{ + FilePayload: urpc.FilePayload{ + Files: []*os.File{ + usage.MemoryAccounting.File, + mf.File(), + }, + }, + } + + return nil +} + +// Collect returns memory used by the sandboxed application. +func (u *Usage) Collect(opts *MemoryUsageOpts, out *MemoryUsage) error { + if opts.Full { + // Ensure everything is up to date. + if err := u.Kernel.MemoryFile().UpdateUsage(); err != nil { + return err + } + + // Copy out a snapshot. + snapshot, total := usage.MemoryAccounting.Copy() + *out = MemoryUsage{ + System: snapshot.System, + Anonymous: snapshot.Anonymous, + PageCache: snapshot.PageCache, + Mapped: snapshot.Mapped, + Tmpfs: snapshot.Tmpfs, + Ramdiskfs: snapshot.Ramdiskfs, + Total: total, + } + } else { + // Get total usage from the MemoryFile implementation. + total, err := u.Kernel.MemoryFile().TotalUsage() + if err != nil { + return err + } + + // The memory accounting is guaranteed to be accurate only when + // UpdateUsage is called. If UpdateUsage is not called, then only Mapped + // will be up-to-date. + snapshot, _ := usage.MemoryAccounting.Copy() + *out = MemoryUsage{ + Unknown: total, + Mapped: snapshot.Mapped, + Total: total + snapshot.Mapped, + } + + } + + return nil +} + +// UsageReduceOpts contains options to Usage.Reduce(). +type UsageReduceOpts struct { + // If Wait is true, Reduce blocks until all activity initiated by + // Usage.Reduce() has completed. + Wait bool `json:"wait"` +} + +// UsageReduceOutput contains output from Usage.Reduce(). +type UsageReduceOutput struct{} + +// Reduce requests that the sentry attempt to reduce its memory usage. +func (u *Usage) Reduce(opts *UsageReduceOpts, out *UsageReduceOutput) error { + mf := u.Kernel.MemoryFile() + mf.StartEvictions() + if opts.Wait { + mf.WaitForEvictions() + } + return nil +} + +// MemoryUsageRecord contains the mapping and platform memory file. +type MemoryUsageRecord struct { + mmap uintptr + stats *usage.RTMemoryStats + mf os.File +} + +// NewMemoryUsageRecord creates a new MemoryUsageRecord from usageFile and +// platformFile. +func NewMemoryUsageRecord(usageFile, platformFile os.File) (*MemoryUsageRecord, error) { + mmap, _, e := unix.RawSyscall6(unix.SYS_MMAP, 0, usage.RTMemoryStatsSize, unix.PROT_READ, unix.MAP_SHARED, usageFile.Fd(), 0) + if e != 0 { + return nil, fmt.Errorf("mmap returned %d, want 0", e) + } + + m := MemoryUsageRecord{ + mmap: mmap, + stats: usage.RTMemoryStatsPointer(mmap), + mf: platformFile, + } + + runtime.SetFinalizer(&m, finalizer) + return &m, nil +} + +func finalizer(m *MemoryUsageRecord) { + unix.RawSyscall(unix.SYS_MUNMAP, m.mmap, usage.RTMemoryStatsSize, 0) +} + +// Fetch fetches the usage info from a MemoryUsageRecord. +func (m *MemoryUsageRecord) Fetch() (mapped, unknown, total uint64, err error) { + var stat unix.Stat_t + if err := unix.Fstat(int(m.mf.Fd()), &stat); err != nil { + return 0, 0, 0, err + } + fmem := uint64(stat.Blocks) * 512 + return m.stats.RTMapped, fmem, m.stats.RTMapped + fmem, nil +} |