From fb1951204c9972d0a4364e24a6f2cd5900b7f2f2 Mon Sep 17 00:00:00 2001
From: Brandon Philips <brandon.philips@coreos.com>
Date: Sat, 8 Aug 2015 17:40:12 -0700
Subject: [PATCH 1/2] etcdserver: move atomics to make etcd work on arm64

Follow the simple rule in the atomic package:

"On both ARM and x86-32, it is the caller's responsibility to arrange
for 64-bit alignment of 64-bit words accessed atomically. The first word
in a global variable or in an allocated struct or slice can be relied
upon to be 64-bit aligned."

Tested on a system with /proc/cpuinfo reporting:

processor       : 0
model name      : ARMv7 Processor rev 1 (v7l)
Features        : swp half thumb fastmult vfp edsp thumbee neon vfpv3
tls vfpv4 idiva idivt vfpd32 lpae evtstrm
CPU implementer : 0x41
CPU architecture: 7
CPU variant     : 0x0
CPU part        : 0xc0d
CPU revision    : 1
---
 etcdserver/raft.go   | 12 +++++++-----
 etcdserver/server.go |  6 ++++--
 store/watcher_hub.go |  6 +++++-
 3 files changed, 16 insertions(+), 8 deletions(-)

diff --git a/etcdserver/raft.go b/etcdserver/raft.go
index 711c8fe61..16838af03 100644
--- a/etcdserver/raft.go
+++ b/etcdserver/raft.go
@@ -79,6 +79,13 @@ type apply struct {
 }
 
 type raftNode struct {
+	// Cache of the latest raft index and raft term the server has seen.
+	// These three unit64 fields must be the first elements to keep 64-bit
+	// alignment for atomic access to the fields.
+	index uint64
+	term  uint64
+	lead  uint64
+
 	raft.Node
 
 	// a chan to send out apply
@@ -99,11 +106,6 @@ type raftNode struct {
 	// If transport is nil, server will panic.
 	transport rafthttp.Transporter
 
-	// Cache of the latest raft index and raft term the server has seen
-	index uint64
-	term  uint64
-	lead  uint64
-
 	stopped chan struct{}
 	done    chan struct{}
 }
diff --git a/etcdserver/server.go b/etcdserver/server.go
index 330029bda..dce70c6f0 100644
--- a/etcdserver/server.go
+++ b/etcdserver/server.go
@@ -141,11 +141,13 @@ type Server interface {
 
 // EtcdServer is the production implementation of the Server interface
 type EtcdServer struct {
+	// r must be the first element to keep 64-bit alignment for atomic
+	// access to fields
+	r raftNode
+
 	cfg       *ServerConfig
 	snapCount uint64
 
-	r raftNode
-
 	w          wait.Wait
 	stop       chan struct{}
 	done       chan struct{}
diff --git a/store/watcher_hub.go b/store/watcher_hub.go
index d27ace06b..d573eb331 100644
--- a/store/watcher_hub.go
+++ b/store/watcher_hub.go
@@ -31,9 +31,13 @@ import (
 // event happens between the end of the first watch command and the start
 // of the second command.
 type watcherHub struct {
+	// count must be the first element to keep 64-bit alignment for atomic
+	// access
+
+	count int64 // current number of watchers.
+
 	mutex        sync.Mutex
 	watchers     map[string]*list.List
-	count        int64 // current number of watchers.
 	EventHistory *EventHistory
 }
 

From 1b894c6b0b8c0689c8c276c0d29367b52cd702de Mon Sep 17 00:00:00 2001
From: Brandon Philips <brandon.philips@coreos.com>
Date: Sat, 8 Aug 2015 17:45:13 -0700
Subject: [PATCH 2/2] test: race detector doesn't work on armv7l

Test fails without this fix on armv7l:

    go test: -race is only supported on linux/amd64, freebsd/amd64, darwin/amd64 and windows/amd64
---
 test | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/test b/test
index 9eb0b23c6..88c23a9b7 100755
--- a/test
+++ b/test
@@ -45,7 +45,13 @@ split=(${NO_RACE_TEST// / })
 NO_RACE_TEST=${split[@]/#/${REPO_PATH}/}
 
 echo "Running tests..."
-go test -timeout 3m ${COVER} $@ ${TEST} --race -cpu 1,2,4
+
+MACHINE_TYPE=$(uname -m)
+if [ $MACHINE_TYPE != "armv7l" ]; then
+  RACE="--race"
+fi
+
+go test -timeout 3m ${COVER} $@ ${TEST} ${RACE} -cpu 1,2,4
 go test -timeout 3m ${COVER} $@ ${NO_RACE_TEST} -cpu 1,2,4
 
 if [ -n "$INTEGRATION" ]; then