runtime: replace sys.CacheLineSize by corresponding internal/cpu const and vars

sys here is runtime/internal/sys.

Replace uses of sys.CacheLineSize for padding by
cpu.CacheLinePad or cpu.CacheLinePadSize.
Replace other uses of sys.CacheLineSize by cpu.CacheLineSize.
Remove now unused sys.CacheLineSize.

Updates #25203

Change-Id: I1daf410fe8f6c0493471c2ceccb9ca0a5a75ed8f
Reviewed-on: https://go-review.googlesource.com/126601
Run-TryBot: Martin Möhrmann <moehrmann@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

src/go/build/deps_test.go

@@ -38,7 +38,7 @@ var pkgDeps = map[string][]string{
 	"io":                      {"errors", "sync", "sync/atomic"},
 	"runtime":                 {"unsafe", "runtime/internal/atomic", "runtime/internal/sys", "internal/cpu", "internal/bytealg"},
 	"runtime/internal/sys":    {},
-	"runtime/internal/atomic": {"unsafe", "runtime/internal/sys"},
+	"runtime/internal/atomic": {"unsafe", "internal/cpu"},
 	"internal/race":           {"runtime", "unsafe"},
 	"sync":                    {"internal/race", "runtime", "sync/atomic", "unsafe"},
 	"sync/atomic":             {"unsafe"},

src/internal/cpu/cpu.go

@@ -17,7 +17,7 @@ type CacheLinePad struct{ _ [CacheLinePadSize]byte }
 // CacheLineSize is the CPU's assumed cache line size.
 // There is currently no runtime detection of the real cache line size
 // so we use the constant per GOARCH CacheLinePadSize as an approximation.
-var CacheLineSize = CacheLinePadSize
+var CacheLineSize uintptr = CacheLinePadSize
 
 var X86 x86
 

src/runtime/internal/atomic/atomic_arm.go

@@ -7,7 +7,7 @@
 package atomic
 
 import (
-	"runtime/internal/sys"
+	"internal/cpu"
 	"unsafe"
 )
 
@@ -31,7 +31,7 @@ func (l *spinlock) unlock() {
 
 var locktab [57]struct {
 	l   spinlock
-	pad [sys.CacheLineSize - unsafe.Sizeof(spinlock{})]byte
+	pad [cpu.CacheLinePadSize - unsafe.Sizeof(spinlock{})]byte
 }
 
 func addrLock(addr *uint64) *spinlock {

src/runtime/internal/atomic/atomic_mipsx.go

@@ -7,14 +7,14 @@
 package atomic
 
 import (
-	"runtime/internal/sys"
+	"internal/cpu"
 	"unsafe"
 )
 
 // TODO implement lock striping
 var lock struct {
 	state uint32
-	pad   [sys.CacheLineSize - 4]byte
+	pad   [cpu.CacheLinePadSize - 4]byte
 }
 
 //go:noescape

src/runtime/internal/sys/arch_386.go

@@ -7,7 +7,6 @@ package sys
 const (
 	ArchFamily          = I386
 	BigEndian           = false
-	CacheLineSize       = 64
 	DefaultPhysPageSize = GoosNacl*65536 + (1-GoosNacl)*4096 // 4k normally; 64k on NaCl
 	PCQuantum           = 1
 	Int64Align          = 4

src/runtime/internal/sys/arch_amd64.go

@@ -7,7 +7,6 @@ package sys
 const (
 	ArchFamily          = AMD64
 	BigEndian           = false
-	CacheLineSize       = 64
 	DefaultPhysPageSize = 4096
 	PCQuantum           = 1
 	Int64Align          = 8

src/runtime/internal/sys/arch_amd64p32.go

@@ -7,7 +7,6 @@ package sys
 const (
 	ArchFamily          = AMD64
 	BigEndian           = false
-	CacheLineSize       = 64
 	DefaultPhysPageSize = 65536*GoosNacl + 4096*(1-GoosNacl)
 	PCQuantum           = 1
 	Int64Align          = 8

src/runtime/internal/sys/arch_arm.go

@@ -7,7 +7,6 @@ package sys
 const (
 	ArchFamily          = ARM
 	BigEndian           = false
-	CacheLineSize       = 32
 	DefaultPhysPageSize = 65536
 	PCQuantum           = 4
 	Int64Align          = 4

src/runtime/internal/sys/arch_arm64.go

@@ -7,7 +7,6 @@ package sys
 const (
 	ArchFamily          = ARM64
 	BigEndian           = false
-	CacheLineSize       = 64
 	DefaultPhysPageSize = 65536
 	PCQuantum           = 4
 	Int64Align          = 8

src/runtime/internal/sys/arch_mips.go

@@ -7,7 +7,6 @@ package sys
 const (
 	ArchFamily          = MIPS
 	BigEndian           = true
-	CacheLineSize       = 32
 	DefaultPhysPageSize = 65536
 	PCQuantum           = 4
 	Int64Align          = 4

src/runtime/internal/sys/arch_mips64.go

@@ -7,7 +7,6 @@ package sys
 const (
 	ArchFamily          = MIPS64
 	BigEndian           = true
-	CacheLineSize       = 32
 	DefaultPhysPageSize = 16384
 	PCQuantum           = 4
 	Int64Align          = 8

src/runtime/internal/sys/arch_mips64le.go

@@ -7,7 +7,6 @@ package sys
 const (
 	ArchFamily          = MIPS64
 	BigEndian           = false
-	CacheLineSize       = 32
 	DefaultPhysPageSize = 16384
 	PCQuantum           = 4
 	Int64Align          = 8

src/runtime/internal/sys/arch_mipsle.go

@@ -7,7 +7,6 @@ package sys
 const (
 	ArchFamily          = MIPS
 	BigEndian           = false
-	CacheLineSize       = 32
 	DefaultPhysPageSize = 65536
 	PCQuantum           = 4
 	Int64Align          = 4

src/runtime/internal/sys/arch_ppc64.go

@@ -7,7 +7,6 @@ package sys
 const (
 	ArchFamily          = PPC64
 	BigEndian           = true
-	CacheLineSize       = 128
 	DefaultPhysPageSize = 65536
 	PCQuantum           = 4
 	Int64Align          = 8

src/runtime/internal/sys/arch_ppc64le.go

@@ -7,7 +7,6 @@ package sys
 const (
 	ArchFamily          = PPC64
 	BigEndian           = false
-	CacheLineSize       = 128
 	DefaultPhysPageSize = 65536
 	PCQuantum           = 4
 	Int64Align          = 8

src/runtime/internal/sys/arch_s390x.go

@@ -7,7 +7,6 @@ package sys
 const (
 	ArchFamily          = S390X
 	BigEndian           = true
-	CacheLineSize       = 256
 	DefaultPhysPageSize = 4096
 	PCQuantum           = 2
 	Int64Align          = 8

src/runtime/internal/sys/arch_wasm.go

@@ -7,7 +7,6 @@ package sys
 const (
 	ArchFamily          = WASM
 	BigEndian           = false
-	CacheLineSize       = 64
 	DefaultPhysPageSize = 65536
 	PCQuantum           = 1
 	Int64Align          = 8

src/runtime/mgc.go

@@ -137,8 +137,8 @@
 package runtime
 
 import (
+	"internal/cpu"
 	"runtime/internal/atomic"
-	"runtime/internal/sys"
 	"unsafe"
 )
 
@@ -414,7 +414,7 @@ type gcControllerState struct {
 	// If this is zero, no fractional workers are needed.
 	fractionalUtilizationGoal float64
 
-	_ [sys.CacheLineSize]byte
+	_ cpu.CacheLinePad
 }
 
 // startCycle resets the GC controller's state and computes estimates
@@ -919,9 +919,9 @@ const gcAssistTimeSlack = 5000
 const gcOverAssistWork = 64 << 10
 
 var work struct {
-	full  lfstack                  // lock-free list of full blocks workbuf
-	empty lfstack                  // lock-free list of empty blocks workbuf
-	pad0  [sys.CacheLineSize]uint8 // prevents false-sharing between full/empty and nproc/nwait
+	full  lfstack          // lock-free list of full blocks workbuf
+	empty lfstack          // lock-free list of empty blocks workbuf
+	pad0  cpu.CacheLinePad // prevents false-sharing between full/empty and nproc/nwait
 
 	wbufSpans struct {
 		lock mutex

src/runtime/mgcsweepbuf.go

@@ -5,6 +5,7 @@
 package runtime
 
 import (
+	"internal/cpu"
 	"runtime/internal/atomic"
 	"runtime/internal/sys"
 	"unsafe"
@@ -83,7 +84,7 @@ retry:
 			if newCap == 0 {
 				newCap = gcSweepBufInitSpineCap
 			}
-			newSpine := persistentalloc(newCap*sys.PtrSize, sys.CacheLineSize, &memstats.gc_sys)
+			newSpine := persistentalloc(newCap*sys.PtrSize, cpu.CacheLineSize, &memstats.gc_sys)
 			if b.spineCap != 0 {
 				// Blocks are allocated off-heap, so
 				// no write barriers.
@@ -102,7 +103,7 @@ retry:
 		}
 
 		// Allocate a new block and add it to the spine.
-		block = (*gcSweepBlock)(persistentalloc(unsafe.Sizeof(gcSweepBlock{}), sys.CacheLineSize, &memstats.gc_sys))
+		block = (*gcSweepBlock)(persistentalloc(unsafe.Sizeof(gcSweepBlock{}), cpu.CacheLineSize, &memstats.gc_sys))
 		blockp := add(b.spine, sys.PtrSize*top)
 		// Blocks are allocated off-heap, so no write barrier.
 		atomic.StorepNoWB(blockp, unsafe.Pointer(block))

src/runtime/mheap.go

@@ -9,6 +9,7 @@
 package runtime
 
 import (
+	"internal/cpu"
 	"runtime/internal/atomic"
 	"runtime/internal/sys"
 	"unsafe"
@@ -137,12 +138,12 @@ type mheap struct {
 
 	// central free lists for small size classes.
 	// the padding makes sure that the MCentrals are
-	// spaced CacheLineSize bytes apart, so that each MCentral.lock
+	// spaced CacheLinePadSize bytes apart, so that each MCentral.lock
 	// gets its own cache line.
 	// central is indexed by spanClass.
 	central [numSpanClasses]struct {
 		mcentral mcentral
-		pad      [sys.CacheLineSize - unsafe.Sizeof(mcentral{})%sys.CacheLineSize]byte
+		pad      [cpu.CacheLinePadSize - unsafe.Sizeof(mcentral{})%cpu.CacheLinePadSize]byte
 	}
 
 	spanalloc             fixalloc // allocator for span*

src/runtime/runtime2.go

@@ -5,6 +5,7 @@
 package runtime
 
 import (
+	"internal/cpu"
 	"runtime/internal/atomic"
 	"runtime/internal/sys"
 	"unsafe"
@@ -548,7 +549,7 @@ type p struct {
 
 	runSafePointFn uint32 // if 1, run sched.safePointFn at next safe point
 
-	pad [sys.CacheLineSize]byte
+	pad cpu.CacheLinePad
 }
 
 type schedt struct {

src/runtime/sema.go

@@ -20,8 +20,8 @@
 package runtime
 
 import (
+	"internal/cpu"
 	"runtime/internal/atomic"
-	"runtime/internal/sys"
 	"unsafe"
 )
 
@@ -48,7 +48,7 @@ const semTabSize = 251
 
 var semtable [semTabSize]struct {
 	root semaRoot
-	pad  [sys.CacheLineSize - unsafe.Sizeof(semaRoot{})]byte
+	pad  [cpu.CacheLinePadSize - unsafe.Sizeof(semaRoot{})]byte
 }
 
 //go:linkname sync_runtime_Semacquire sync.runtime_Semacquire

src/runtime/time.go

@@ -7,7 +7,7 @@
 package runtime
 
 import (
-	"runtime/internal/sys"
+	"internal/cpu"
 	"unsafe"
 )
 
@@ -50,7 +50,7 @@ var timers [timersLen]struct {
 
 	// The padding should eliminate false sharing
 	// between timersBucket values.
-	pad [sys.CacheLineSize - unsafe.Sizeof(timersBucket{})%sys.CacheLineSize]byte
+	pad [cpu.CacheLinePadSize - unsafe.Sizeof(timersBucket{})%cpu.CacheLinePadSize]byte
 }
 
 func (t *timer) assignBucket() *timersBucket {