fsmetric

Documentation

Overview

Package fsmetric defines filesystem metrics that are used by both VFS1 and VFS2.

TODO(gvisor.dev/issue/1624): Once VFS1 is deleted, inline these metrics into VFS2.

Index

• Variables
• func FinishReadWait(m *metric.Uint64Metric, start time.Time)
• func StartReadWait() time.Time

Variables

var (
	Opens    = metric.MustCreateNewUint64Metric("/fs/opens", false, "Number of file opens.")
	Reads    = metric.MustCreateNewUint64Metric("/fs/reads", false, "Number of file reads.")
	ReadWait = metric.MustCreateNewUint64NanosecondsMetric("/fs/read_wait", false, "Time waiting on file reads, in nanoseconds.")
)

Metrics that apply to all filesystems.

var (
	GoferOpens9P      = metric.MustCreateNewUint64Metric("/gofer/opens_9p", false, "Number of times a file was opened from a gofer and did not have a host file descriptor.")
	GoferOpensHost    = metric.MustCreateNewUint64Metric("/gofer/opens_host", false, "Number of times a file was opened from a gofer and did have a host file descriptor.")
	GoferReads9P      = metric.MustCreateNewUint64Metric("/gofer/reads_9p", false, "Number of 9P file reads from a gofer.")
	GoferReadWait9P   = metric.MustCreateNewUint64NanosecondsMetric("/gofer/read_wait_9p", false, "Time waiting on 9P file reads from a gofer, in nanoseconds.")
	GoferReadsHost    = metric.MustCreateNewUint64Metric("/gofer/reads_host", false, "Number of host file reads from a gofer.")
	GoferReadWaitHost = metric.MustCreateNewUint64NanosecondsMetric("/gofer/read_wait_host", false, "Time waiting on host file reads from a gofer, in nanoseconds.")
)

Metrics that only apply to fs/gofer and fsimpl/gofer.

var (
	TmpfsOpensRO  = metric.MustCreateNewUint64Metric("/in_memory_file/opens_ro", false, "Number of times an in-memory file was opened in read-only mode.")
	TmpfsOpensW   = metric.MustCreateNewUint64Metric("/in_memory_file/opens_w", false, "Number of times an in-memory file was opened in write mode.")
	TmpfsReads    = metric.MustCreateNewUint64Metric("/in_memory_file/reads", false, "Number of in-memory file reads.")
	TmpfsReadWait = metric.MustCreateNewUint64NanosecondsMetric("/in_memory_file/read_wait", false, "Time waiting on in-memory file reads, in nanoseconds.")
)

Metrics that only apply to fs/tmpfs and fsimpl/tmpfs.

var RecordWaitTime = false

RecordWaitTime enables the ReadWait, GoferReadWait9P, GoferReadWaitHost, and TmpfsReadWait metrics. Enabling this comes at a CPU cost due to performing three clock reads per read call.

Note that this is only performed in the direct read path, and may not be consistently applied for other forms of reads, such as splice.

Functions

func FinishReadWait

func FinishReadWait(m *metric.Uint64Metric, start time.Time)

FinishReadWait indicates the end of a file read whose time is accounted by m. start must be the value returned by the corresponding call to StartReadWait.

FinishReadWait is marked nosplit for performance since it's often called from defer statements, which prevents it from being inlined (https://github.com/golang/go/issues/38471).

func StartReadWait

func StartReadWait() time.Time

StartReadWait indicates the beginning of a file read.