unix: defer Getpagesize() to runtime

In general, page size is not a function of the archetecture. This was addressed in the Go standard library here: https://go-review.googlesource.com/25051 This change simply defers to the standard library "syscall" package, which in turn defers to the runtime. This helps in addressing golang/go#10180 and also fixes a bug on ppc64. Currently, we return 65536 as the page size on ppc64, but the kernel supports 4k and 64k sizes, see here: http://elixir.free-electrons.com/linux/v4.13/source/arch/powerpc/include/asm/page.h#L24 Now that various page size calculations are not needed, various components are now dead code and can also be removed. This CL reverts: https://go-review.googlesource.com/14483 and part of: https://go-review.googlesource.com/30755 Change-Id: I9d7a2d96359054e0dca9c985b026c8072b2eeaf3 Reviewed-on: https://go-review.googlesource.com/62111 Reviewed-by: Austin Clements <austin@google.com> Run-TryBot: Austin Clements <austin@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org>
micanzhang · Sep 12, 2017 · 757c3cd · 757c3cd
1 parent 22e5721
commit 757c3cd
Show file tree

Hide file tree

Showing 40 changed files with 16 additions and 145 deletions.
diff --git a/unix/gccgo_linux_sparc64.go b/unix/gccgo_linux_sparc64.go
diff --git a/unix/linux/types.go b/unix/linux/types.go
@@ -535,10 +535,6 @@ const RNDGETENTCNT = C.RNDGETENTCNT
 
 const PERF_IOC_FLAG_GROUP = C.PERF_IOC_FLAG_GROUP
 
-// sysconf information
-
-const _SC_PAGESIZE = C._SC_PAGESIZE
-
 // Terminal handling
 
 type Termios C.termios_t

diff --git a/unix/pagesize_unix.go b/unix/pagesize_unix.go
@@ -0,0 +1,15 @@
+// Copyright 2017 The Go Authors.  All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build darwin dragonfly freebsd linux netbsd openbsd solaris
+
+// For Unix, get the pagesize from the runtime.
+
+package unix
+
+import "syscall"
+
+func Getpagesize() int {
+	return syscall.Getpagesize()
+}
diff --git a/unix/syscall_darwin_386.go b/unix/syscall_darwin_386.go
@@ -11,8 +11,6 @@ import (
 	"unsafe"
 )
 
-func Getpagesize() int { return 4096 }
-
 func TimespecToNsec(ts Timespec) int64 { return int64(ts.Sec)*1e9 + int64(ts.Nsec) }
 
 func NsecToTimespec(nsec int64) (ts Timespec) {

diff --git a/unix/syscall_darwin_amd64.go b/unix/syscall_darwin_amd64.go
@@ -11,8 +11,6 @@ import (
 	"unsafe"
 )
 
-func Getpagesize() int { return 4096 }
-
 func TimespecToNsec(ts Timespec) int64 { return int64(ts.Sec)*1e9 + int64(ts.Nsec) }
 
 func NsecToTimespec(nsec int64) (ts Timespec) {

diff --git a/unix/syscall_darwin_arm.go b/unix/syscall_darwin_arm.go
@@ -9,8 +9,6 @@ import (
 	"unsafe"
 )
 
-func Getpagesize() int { return 4096 }
-
 func TimespecToNsec(ts Timespec) int64 { return int64(ts.Sec)*1e9 + int64(ts.Nsec) }
 
 func NsecToTimespec(nsec int64) (ts Timespec) {

diff --git a/unix/syscall_darwin_arm64.go b/unix/syscall_darwin_arm64.go
@@ -11,8 +11,6 @@ import (
 	"unsafe"
 )
 
-func Getpagesize() int { return 16384 }
-
 func TimespecToNsec(ts Timespec) int64 { return int64(ts.Sec)*1e9 + int64(ts.Nsec) }
 
 func NsecToTimespec(nsec int64) (ts Timespec) {

diff --git a/unix/syscall_dragonfly_amd64.go b/unix/syscall_dragonfly_amd64.go
@@ -11,8 +11,6 @@ import (
 	"unsafe"
 )
 
-func Getpagesize() int { return 4096 }
-
 func TimespecToNsec(ts Timespec) int64 { return int64(ts.Sec)*1e9 + int64(ts.Nsec) }
 
 func NsecToTimespec(nsec int64) (ts Timespec) {

diff --git a/unix/syscall_freebsd_386.go b/unix/syscall_freebsd_386.go
@@ -11,8 +11,6 @@ import (
 	"unsafe"
 )
 
-func Getpagesize() int { return 4096 }
-
 func TimespecToNsec(ts Timespec) int64 { return int64(ts.Sec)*1e9 + int64(ts.Nsec) }
 
 func NsecToTimespec(nsec int64) (ts Timespec) {

diff --git a/unix/syscall_freebsd_amd64.go b/unix/syscall_freebsd_amd64.go
@@ -11,8 +11,6 @@ import (
 	"unsafe"
 )
 
-func Getpagesize() int { return 4096 }
-
 func TimespecToNsec(ts Timespec) int64 { return int64(ts.Sec)*1e9 + int64(ts.Nsec) }
 
 func NsecToTimespec(nsec int64) (ts Timespec) {

diff --git a/unix/syscall_freebsd_arm.go b/unix/syscall_freebsd_arm.go
@@ -11,8 +11,6 @@ import (
 	"unsafe"
 )
 
-func Getpagesize() int { return 4096 }
-
 func TimespecToNsec(ts Timespec) int64 { return ts.Sec*1e9 + int64(ts.Nsec) }
 
 func NsecToTimespec(nsec int64) (ts Timespec) {

diff --git a/unix/syscall_linux_386.go b/unix/syscall_linux_386.go
@@ -14,8 +14,6 @@ import (
 	"unsafe"
 )
 
-func Getpagesize() int { return 4096 }
-
 func TimespecToNsec(ts Timespec) int64 { return int64(ts.Sec)*1e9 + int64(ts.Nsec) }
 
 func NsecToTimespec(nsec int64) (ts Timespec) {

diff --git a/unix/syscall_linux_amd64.go b/unix/syscall_linux_amd64.go
@@ -69,8 +69,6 @@ func Gettimeofday(tv *Timeval) (err error) {
 	return nil
 }
 
-func Getpagesize() int { return 4096 }
-
 func Time(t *Time_t) (tt Time_t, err error) {
 	var tv Timeval
 	errno := gettimeofday(&tv)

diff --git a/unix/syscall_linux_arm.go b/unix/syscall_linux_arm.go
@@ -11,8 +11,6 @@ import (
 	"unsafe"
 )
 
-func Getpagesize() int { return 4096 }
-
 func TimespecToNsec(ts Timespec) int64 { return int64(ts.Sec)*1e9 + int64(ts.Nsec) }
 
 func NsecToTimespec(nsec int64) (ts Timespec) {

diff --git a/unix/syscall_linux_arm64.go b/unix/syscall_linux_arm64.go
@@ -66,8 +66,6 @@ func Lstat(path string, stat *Stat_t) (err error) {
 //sys	sendmsg(s int, msg *Msghdr, flags int) (n int, err error)
 //sys	mmap(addr uintptr, length uintptr, prot int, flags int, fd int, offset int64) (xaddr uintptr, err error)
 
-func Getpagesize() int { return 65536 }
-
 //sysnb	Gettimeofday(tv *Timeval) (err error)
 
 func TimespecToNsec(ts Timespec) int64 { return int64(ts.Sec)*1e9 + int64(ts.Nsec) }

diff --git a/unix/syscall_linux_mips64x.go b/unix/syscall_linux_mips64x.go
@@ -55,8 +55,6 @@ package unix
 //sys	sendmsg(s int, msg *Msghdr, flags int) (n int, err error)
 //sys	mmap(addr uintptr, length uintptr, prot int, flags int, fd int, offset int64) (xaddr uintptr, err error)
 
-func Getpagesize() int { return 65536 }
-
 //sysnb	Gettimeofday(tv *Timeval) (err error)
 
 func Time(t *Time_t) (tt Time_t, err error) {

diff --git a/unix/syscall_linux_mipsx.go b/unix/syscall_linux_mipsx.go
@@ -235,5 +235,3 @@ func Poll(fds []PollFd, timeout int) (n int, err error) {
 	}
 	return poll(&fds[0], len(fds), timeout)
 }
-
-func Getpagesize() int { return 4096 }
diff --git a/unix/syscall_linux_ppc64x.go b/unix/syscall_linux_ppc64x.go
@@ -61,8 +61,6 @@ package unix
 //sys	sendmsg(s int, msg *Msghdr, flags int) (n int, err error)
 //sys	mmap(addr uintptr, length uintptr, prot int, flags int, fd int, offset int64) (xaddr uintptr, err error)
 
-func Getpagesize() int { return 65536 }
-
 //sysnb	Gettimeofday(tv *Timeval) (err error)
 //sysnb	Time(t *Time_t) (tt Time_t, err error)
 

diff --git a/unix/syscall_linux_s390x.go b/unix/syscall_linux_s390x.go
@@ -46,8 +46,6 @@ import (
 //sysnb	getgroups(n int, list *_Gid_t) (nn int, err error)
 //sysnb	setgroups(n int, list *_Gid_t) (err error)
 
-func Getpagesize() int { return 4096 }
-
 //sysnb	Gettimeofday(tv *Timeval) (err error)
 
 func Time(t *Time_t) (tt Time_t, err error) {

diff --git a/unix/syscall_linux_sparc64.go b/unix/syscall_linux_sparc64.go
@@ -6,11 +6,6 @@
 
 package unix
 
-import (
-	"sync/atomic"
-	"syscall"
-)
-
 //sys	EpollWait(epfd int, events []EpollEvent, msec int) (n int, err error)
 //sys	Dup2(oldfd int, newfd int) (err error)
 //sys	Fchown(fd int, uid int, gid int) (err error)
@@ -63,21 +58,6 @@ import (
 //sys	sendmsg(s int, msg *Msghdr, flags int) (n int, err error)
 //sys	mmap(addr uintptr, length uintptr, prot int, flags int, fd int, offset int64) (xaddr uintptr, err error)
 
-func sysconf(name int) (n int64, err syscall.Errno)
-
-// pageSize caches the value of Getpagesize, since it can't change
-// once the system is booted.
-var pageSize int64 // accessed atomically
-
-func Getpagesize() int {
-	n := atomic.LoadInt64(&pageSize)
-	if n == 0 {
-		n, _ = sysconf(_SC_PAGESIZE)
-		atomic.StoreInt64(&pageSize, n)
-	}
-	return int(n)
-}
-
 func Ioperm(from int, num int, on int) (err error) {
 	return ENOSYS
 }

diff --git a/unix/syscall_netbsd_386.go b/unix/syscall_netbsd_386.go
@@ -6,8 +6,6 @@
 
 package unix
 
-func Getpagesize() int { return 4096 }
-
 func TimespecToNsec(ts Timespec) int64 { return int64(ts.Sec)*1e9 + int64(ts.Nsec) }
 
 func NsecToTimespec(nsec int64) (ts Timespec) {

diff --git a/unix/syscall_netbsd_amd64.go b/unix/syscall_netbsd_amd64.go
@@ -6,8 +6,6 @@
 
 package unix
 
-func Getpagesize() int { return 4096 }
-
 func TimespecToNsec(ts Timespec) int64 { return int64(ts.Sec)*1e9 + int64(ts.Nsec) }
 
 func NsecToTimespec(nsec int64) (ts Timespec) {

diff --git a/unix/syscall_netbsd_arm.go b/unix/syscall_netbsd_arm.go
@@ -6,8 +6,6 @@
 
 package unix
 
-func Getpagesize() int { return 4096 }
-
 func TimespecToNsec(ts Timespec) int64 { return int64(ts.Sec)*1e9 + int64(ts.Nsec) }
 
 func NsecToTimespec(nsec int64) (ts Timespec) {

diff --git a/unix/syscall_openbsd_386.go b/unix/syscall_openbsd_386.go
@@ -6,8 +6,6 @@
 
 package unix
 
-func Getpagesize() int { return 4096 }
-
 func TimespecToNsec(ts Timespec) int64 { return int64(ts.Sec)*1e9 + int64(ts.Nsec) }
 
 func NsecToTimespec(nsec int64) (ts Timespec) {

diff --git a/unix/syscall_openbsd_amd64.go b/unix/syscall_openbsd_amd64.go
@@ -6,8 +6,6 @@
 
 package unix
 
-func Getpagesize() int { return 4096 }
-
 func TimespecToNsec(ts Timespec) int64 { return int64(ts.Sec)*1e9 + int64(ts.Nsec) }
 
 func NsecToTimespec(nsec int64) (ts Timespec) {

diff --git a/unix/syscall_openbsd_arm.go b/unix/syscall_openbsd_arm.go
@@ -6,10 +6,6 @@
 
 package unix
 
-import "syscall"
-
-func Getpagesize() int { return syscall.Getpagesize() }
-
 func TimespecToNsec(ts Timespec) int64 { return int64(ts.Sec)*1e9 + int64(ts.Nsec) }
 
 func NsecToTimespec(nsec int64) (ts Timespec) {

diff --git a/unix/syscall_solaris.go b/unix/syscall_solaris.go
@@ -13,7 +13,6 @@
 package unix
 
 import (
-	"sync/atomic"
 	"syscall"
 	"unsafe"
 )
@@ -699,18 +698,3 @@ func Mmap(fd int, offset int64, length int, prot int, flags int) (data []byte, e
 func Munmap(b []byte) (err error) {
 	return mapper.Munmap(b)
 }
-
-//sys	sysconf(name int) (n int64, err error)
-
-// pageSize caches the value of Getpagesize, since it can't change
-// once the system is booted.
-var pageSize int64 // accessed atomically
-
-func Getpagesize() int {
-	n := atomic.LoadInt64(&pageSize)
-	if n == 0 {
-		n, _ = sysconf(_SC_PAGESIZE)
-		atomic.StoreInt64(&pageSize, n)
-	}
-	return int(n)
-}
diff --git a/unix/types_solaris.go b/unix/types_solaris.go
@@ -256,10 +256,6 @@ type BpfTimeval C.struct_bpf_timeval
 
 type BpfHdr C.struct_bpf_hdr
 
-// sysconf information
-
-const _SC_PAGESIZE = C._SC_PAGESIZE
-
 // Terminal handling
 
 type Termios C.struct_termios

diff --git a/unix/zsyscall_solaris_amd64.go b/unix/zsyscall_solaris_amd64.go
diff --git a/unix/ztypes_linux_386.go b/unix/ztypes_linux_386.go
diff --git a/unix/ztypes_linux_amd64.go b/unix/ztypes_linux_amd64.go
diff --git a/unix/ztypes_linux_arm.go b/unix/ztypes_linux_arm.go
diff --git a/unix/ztypes_linux_arm64.go b/unix/ztypes_linux_arm64.go
-Original file line number
+Diff line change
@@ Expand Up / @@ -235,5 +235,3 @@ func Poll(fds []PollFd, timeout int) (n int, err error) { @@
     	}
     	return poll(&fds[0], len(fds), timeout)
     }
-    func Getpagesize() int { return 4096 }