Stowage/go
2
0
Fork 0
mirror of https://github.com/golang/go.git synced 2025-12-08 06:10:04 +00:00
Code Issues Projects Releases Packages Wiki Activity

runtime: add page tracer

Browse source 
This change adds a new GODEBUG flag called pagetrace that writes a
low-overhead trace of how pages of memory are managed by the Go runtime.

The page tracer is kept behind a GOEXPERIMENT flag due to a potential
security risk for setuid binaries.

Change-Id: I6f4a2447d02693c25214400846a5d2832ad6e5c0
Reviewed-on: https://go-review.googlesource.com/c/go/+/444157
Reviewed-by: Austin Clements <austin@google.com>
Reviewed-by: David Chase <drchase@google.com>
Run-TryBot: Michael Knyszek <mknyszek@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
This commit is contained in:
Michael Knyszek 2022-10-19 14:51:15 -04:00
parent 0613418c98
commit e4435cb844
51 changed files with 636 additions and 29 deletions
Download patch file Download diff file Expand all files Collapse all files

61
src/runtime/proc.go
View file

@ -612,16 +612,39 @@ const (
_GoidCacheBatch = 16
)
// cpuinit extracts the environment variable GODEBUG from the environment on
// Unix-like operating systems and calls internal/cpu.Initialize.
func cpuinit() {
const prefix = "GODEBUG="
var env string
// cpuinit sets up CPU feature flags and calls internal/cpu.Initialize. env should be the complete
// value of the GODEBUG environment variable.
func cpuinit(env string) {
switch GOOS {
case "aix", "darwin", "ios", "dragonfly", "freebsd", "netbsd", "openbsd", "illumos", "solaris", "linux":
cpu.DebugOptions = true
}
cpu.Initialize(env)
// Support cpu feature variables are used in code generated by the compiler
// to guard execution of instructions that can not be assumed to be always supported.
switch GOARCH {
case "386", "amd64":
x86HasPOPCNT = cpu.X86.HasPOPCNT
x86HasSSE41 = cpu.X86.HasSSE41
x86HasFMA = cpu.X86.HasFMA
case "arm":
armHasVFPv4 = cpu.ARM.HasVFPv4
case "arm64":
arm64HasATOMICS = cpu.ARM64.HasATOMICS
}
}
// getGodebugEarly extracts the environment variable GODEBUG from the environment on
// Unix-like operating systems and returns it. This function exists to extract GODEBUG
// early before much of the runtime is initialized.
func getGodebugEarly() string {
const prefix = "GODEBUG="
var env string
switch GOOS {
case "aix", "darwin", "ios", "dragonfly", "freebsd", "netbsd", "openbsd", "illumos", "solaris", "linux":
// Similar to goenv_unix but extracts the environment value for
// GODEBUG directly.
// TODO(moehrmann): remove when general goenvs() can be called before cpuinit()
@ -640,23 +663,7 @@ func cpuinit() {
}
}
}
cpu.Initialize(env)
// Support cpu feature variables are used in code generated by the compiler
// to guard execution of instructions that can not be assumed to be always supported.
switch GOARCH {
case "386", "amd64":
x86HasPOPCNT = cpu.X86.HasPOPCNT
x86HasSSE41 = cpu.X86.HasSSE41
x86HasFMA = cpu.X86.HasFMA
case "arm":
armHasVFPv4 = cpu.ARM.HasVFPv4
case "arm64":
arm64HasATOMICS = cpu.ARM64.HasATOMICS
}
return env
}
// The bootstrap sequence is:
@ -703,9 +710,11 @@ func schedinit() {
moduledataverify()
stackinit()
mallocinit()
cpuinit() // must run before alginit
alginit() // maps, hash, fastrand must not be used before this call
fastrandinit() // must run before mcommoninit
godebug := getGodebugEarly()
initPageTrace(godebug) // must run after mallocinit but before anything allocates
cpuinit(godebug) // must run before alginit
alginit() // maps, hash, fastrand must not be used before this call
fastrandinit() // must run before mcommoninit
mcommoninit(gp.m, -1)
modulesinit() // provides activeModules
typelinksinit() // uses maps, activeModules