(merged) cpuhotplug fixes

index f91cf88..52598a9 100755
@@ -45,13 +45,8 @@ do_clean()
 {
 	kill_pid ${WRL_ID}
 
-	# Turns off the cpus that were off before the test start
-	until [ $CPU_COUNT -eq 0 ]; do
-		offline_cpu=$(eval "echo \$OFFLINE_CPU_${CPU_COUNT}")
-		tst_resm TINFO "CPU = $CPU_COUNT @on = $offline_cpu"
-		offline_cpu $offline_cpu
-		CPU_COUNT=$((CPU_COUNT-1))
-	done
+	# Restore CPU states
+	set_all_cpu_states "$cpu_states"
 }
 
 

@@ -138,6 +133,8 @@ fi
 
 TST_CLEANUP=do_clean
 
+cpu_states=$(get_all_cpu_states)
+
 CPU_COUNT=0
 
 # Start up a process that writes to disk; keep track of its PID

index 8176fb3..817f066 100755
@@ -46,11 +46,8 @@ do_clean()
 		rm /var/run/hotplug4_$$.pid
 	fi
 
-	# Turn off the CPUs that were off before the test start
-	until [ $cpu -eq 0 ];do
-		offline_cpu $(eval "echo \$on_${cpu}")
-		cpu=$((cpu-1))
-	done
+	# Restore CPU states
+	set_all_cpu_states "$cpu_states"
 }
 
 while getopts c:l: OPTION; do

@@ -82,11 +79,13 @@ fi
 
 TST_CLEANUP=do_clean
 
+cpu_states=$(get_all_cpu_states)
+
 until [ $LOOP_COUNT -gt $HOTPLUG03_LOOPS ]; do
 	cpu=0
 	number_of_cpus=0
 
-	# Turns on all CPUs and saves their states
+	# Turns on all CPUs
 	for i in $( get_all_cpus ); do
             if [ "$i" = "cpu0" ]; then
                 continue

@@ -96,7 +95,6 @@ until [ $LOOP_COUNT -gt $HOTPLUG03_LOOPS ]; do
                     tst_brkm TBROK "Could not online cpu $i"
                 fi
 				cpu=$((cpu+1))
-                eval "on_${cpu}=$i"
             fi
 		number_of_cpus=$((number_of_cpus+1))
 	done

index 72fbc6e..ea2723b 100755
@@ -33,17 +33,8 @@ EOF
 do_clean()
 {
 	# Online the ones that were on initially
-	until [ $cpu -eq 0 ]; do
-		online_cpu $(eval "echo \$on_${cpu}")
-		cpu=$((cpu-1))
-	done
-
-	# Return CPU 0 to its initial state
-	if [ $cpustate = 1 ]; then
-		online_cpu 0
-	else
-		offline_cpu 0
-	fi
+	# Restore CPU states
+	set_all_cpu_states "$cpu_states"
 }
 
 while getopts l: OPTION; do

@@ -64,11 +55,13 @@ fi
 
 TST_CLEANUP=do_clean
 
+cpu_states=$(get_all_cpu_states)
+
 until [ $LOOP_COUNT -gt $HOTPLUG04_LOOPS ]; do
 	cpu=0
 	cpustate=1
 
-	# Online all the CPUs' keep track of which were already on
+	# Online all the CPUs
 	for i in $(get_all_cpus); do
 		if [ "$i" != "cpu0" ]; then
 			if ! cpu_is_online $i; then

@@ -77,7 +70,6 @@ until [ $LOOP_COUNT -gt $HOTPLUG04_LOOPS ]; do
 				fi
 			fi
 			cpu=$((cpu+1))
-			eval "on_${cpu}=$i"
 			echo $i
 		else
 			if online_cpu $i; then

index dd8472f..f553d0c 100644
@@ -73,6 +73,9 @@ online_cpu()
     if [ ! -w /sys/devices/system/cpu/cpu${CPU}/online ]; then
         return 1
     fi
+
+    cpu_is_online ${CPU} && return 0
+
     $TIME echo 1 > /sys/devices/system/cpu/cpu${CPU}/online
     RC=$?
     report_timing "Online cpu ${CPU}"

@@ -91,6 +94,9 @@ offline_cpu()
     if [ ! -w /sys/devices/system/cpu/cpu${CPU}/online ]; then
         return 1
     fi
+
+    ! cpu_is_online ${CPU} && return 0
+
     $TIME echo 0 > /sys/devices/system/cpu/cpu${CPU}/online
     RC=$?
     report_timing "Offline cpu ${CPU}"

@@ -141,20 +147,18 @@ get_all_cpu_states()
 
 # set_all_cpu_states(STATES)
 #
-#  Sets all of the CPU states according to $STATE, which must be
+#  Sets all of the CPU states according to STATES, which must be
 #  of the form "cpuX:Y", where X is the CPU number and Y its state.
 #  Each must be on a separate line.
 #
 set_all_cpu_states()
 {
-    for cpu_state in $STATE; do
-        cpu=`echo $c | cut -d: -f 1`
-        state=`echo $c | cut -d: -f 1`
+    for cpu_state in $1; do
+        cpu=`echo $cpu_state | cut -d: -f 1`
+        state=`echo $cpu_state | cut -d: -f 2`
         if [ $state = 1 ]; then
-            echo "# Re-onlining $cpu"
             online_cpu $cpu
         else
-            echo "# Re-offlining $cpu"
             offline_cpu $cpu
         fi
     done

index f553d0c..6920393 100644
@@ -126,11 +126,78 @@ get_cpus_num()
 #
 get_all_cpus()
 {
-    [ -d /sys/devices/system/cpu/cpu0 ] || return 1
-    ls -dr /sys/devices/system/cpu/cpu[0-9]* | \
-        sed "s/\/sys\/devices\/system\/cpu\///g" || return 2
+    [ -d /sys/devices/system/cpu ] || return 1
+    (cd /sys/devices/system/cpu; ls -d cpu[0-9]*)
 }
 
+# get_present_cpus()
+#
+#  Prints a list of present CPUs, regardless of whether they're
+#  currently online or offline.
+#
+get_present_cpus()
+{
+    local present_mask="/sys/devices/system/cpu/present"
+    local present_cpus=""
+
+    # if sysfs present mask is missing, assume all cpu are present
+    if [ ! -e "$present_mask" ]; then
+        get_all_cpus
+        return
+    fi
+
+    for part in $(cat $present_mask | tr "," " "); do
+        if echo $part | grep -q "-"; then
+            range_low=$(echo $part | cut -d - -f 1)
+            range_high=$(echo $part | cut -d - -f 2)
+        else
+            range_low=$(part)
+            range_high=$(part)
+        fi
+        for cpu in $(seq $range_low $range_high); do
+            if [ -e /sys/devices/system/cpu/cpu$cpu ]; then
+                present_cpus="$present_cpus cpu$cpu"
+            fi
+        done
+    done
+    echo $present_cpus
+}
+
+# get_present_cpus_num()
+#
+#  Prints the number of present CPUs
+#
+get_present_cpus_num()
+{
+    return $(get_present_cpus | wc -w)
+}
+
+# get_hotplug_cpus()
+#
+#  Prints a list of present hotpluggable CPUs, regardless of whether they're
+#  currently online or offline.
+#
+get_hotplug_cpus()
+{
+    local present_cpus=$(get_present_cpus)
+    local hotplug_cpus=""
+
+    for cpu in $present_cpus; do
+        if [ -e /sys/devices/system/cpu/$cpu/online ]; then
+            hotplug_cpus="$hotplug_cpus $cpu"
+	fi
+    done
+    echo $hotplug_cpus
+}
+
+# get_hotplug_cpus_num()
+#
+#  Prints the number of hotpluggable CPUs
+#
+get_hotplug_cpus_num()
+{
+    return $(get_hotplug_cpus | wc -w)
+}
 
 # get_all_cpu_states()
 #

index 52598a9..8ae1379 100755
@@ -111,7 +111,7 @@ LOOP_COUNT=1
 
 tst_check_cmds perl
 
-get_cpus_num
+get_present_cpus_num
 if [ $? -lt 2 ]; then
 	tst_brkm TCONF "system doesn't have required CPU hotplug support"
 fi

@@ -148,7 +148,7 @@ do
 	IRQ_START=$(cat /proc/interrupts)
 
 	# Attempt to offline all CPUs
-	for cpu in $( get_all_cpus ); do
+	for cpu in $( get_hotplug_cpus ); do
 		if [ "$cpu" = "cpu0" ]; then
 			continue
 		fi

@@ -163,7 +163,7 @@ do
 	done
 
 	# Attempt to online all CPUs
-	for cpu in $( get_all_cpus ); do
+	for cpu in $( get_hotplug_cpus ); do
 		if [ "$cpu" = "cpu0" ]; then
 			continue
 		fi

index 3b33720..c42cc1b 100755
@@ -54,7 +54,7 @@ done
 
 LOOP_COUNT=1
 
-get_cpus_num
+get_present_cpus_num
 if [ $? -lt 2 ]; then
 	tst_brkm TCONF "system doesn't have required CPU hotplug support"
 fi

index 817f066..3469b10 100755
@@ -63,8 +63,9 @@ done
 
 LOOP_COUNT=1
 
-get_cpus_num
-if [ $? -lt 2 ]; then
+get_present_cpus_num
+cpus_num=$?
+if [ $cpus_num -lt 2 ]; then
 	tst_brkm TCONF "system doesn't have required CPU hotplug support"
 fi
 

@@ -82,21 +83,14 @@ TST_CLEANUP=do_clean
 cpu_states=$(get_all_cpu_states)
 
 until [ $LOOP_COUNT -gt $HOTPLUG03_LOOPS ]; do
-	cpu=0
-	number_of_cpus=0
 
 	# Turns on all CPUs
-	for i in $( get_all_cpus ); do
-            if [ "$i" = "cpu0" ]; then
-                continue
-            fi
+	for i in $( get_hotplug_cpus ); do
             if ! cpu_is_online $i; then
 				if ! online_cpu $i; then
                     tst_brkm TBROK "Could not online cpu $i"
                 fi
-				cpu=$((cpu+1))
             fi
-		number_of_cpus=$((number_of_cpus+1))
 	done
 
 	if ! offline_cpu ${CPU_TO_TEST} ; then

@@ -107,11 +101,11 @@ until [ $LOOP_COUNT -gt $HOTPLUG03_LOOPS ]; do
 	# CPUs we have.  This is to help ensure we've got enough processes
 	# that at least one will migrate to the new CPU.  Store the PIDs
 	# so we can kill them later.
-	number_of_cpus=$((number_of_cpus*2))
-	until [ $number_of_cpus -eq 0 ]; do
+	number_of_procs=$((cpus_num*2))
+	until [ $number_of_procs -eq 0 ]; do
 		cpuhotplug_do_spin_loop > /dev/null 2>&1 &
 		echo $! >> /var/run/hotplug4_$$.pid
-		number_of_cpus=$((number_of_cpus-1))
+		number_of_procs=$((number_of_procs-1))
 	done
 
 	ps aux | head -n 1

index ea2723b..3e025da 100755
@@ -62,7 +62,7 @@ until [ $LOOP_COUNT -gt $HOTPLUG04_LOOPS ]; do
 	cpustate=1
 
 	# Online all the CPUs
-	for i in $(get_all_cpus); do
+	for i in $(get_hotplug_cpus); do
 		if [ "$i" != "cpu0" ]; then
 			if ! cpu_is_online $i; then
 				if ! online_cpu $i; then

@@ -79,7 +79,7 @@ until [ $LOOP_COUNT -gt $HOTPLUG04_LOOPS ]; do
 	done
 
 	# Now offline all the CPUs
-	for i in $(get_all_cpus); do
+	for i in $(get_hotplug_cpus); do
 		if ! offline_cpu $i; then
 			if [ "x$i" != "xcpu0" ]; then
 				tst_resm TFAIL "Did not offline first CPU (offlined $i instead)"

index bb0e896..79f7e90 100755
@@ -54,7 +54,7 @@ LOOP_COUNT=1
 
 tst_check_cmds sar
 
-get_cpus_num
+get_present_cpus_num
 if [ $? -lt 2 ]; then
 	tst_brkm TCONF "system doesn't have required CPU hotplug support"
 fi

index 2e48242..6710fad 100755
@@ -49,7 +49,7 @@ done
 
 LOOP_COUNT=1
 
-get_cpus_num
+get_present_cpus_num
 if [ $? -lt 2 ]; then
 	tst_brkm TCONF "system doesn't have required CPU hotplug support"
 fi

index 723f3de..7edb3a9 100755
@@ -55,7 +55,7 @@ done
 
 LOOP_COUNT=1
 
-get_cpus_num
+get_present_cpus_num
 if [ $? -lt 2 ]; then
 	tst_brkm TCONF "system doesn't have required CPU hotplug support"
 fi

index 3e025da..58a822e 100755
@@ -48,42 +48,50 @@ done
 
 LOOP_COUNT=1
 
-get_cpus_num
-if [ $? -lt 2 ]; then
+get_present_cpus_num
+cpus_num=$?
+if [ $cpus_num -lt 2 ]; then
 	tst_brkm TCONF "system doesn't have required CPU hotplug support"
 fi
 
+get_hotplug_cpus_num
+if [ $? -lt 1 ]; then
+	tst_brkm TCONF "system doesn't have at least one hotpluggable CPU"
+fi
+
 TST_CLEANUP=do_clean
 
 cpu_states=$(get_all_cpu_states)
 
 until [ $LOOP_COUNT -gt $HOTPLUG04_LOOPS ]; do
-	cpu=0
-	cpustate=1
 
-	# Online all the CPUs
+	# Online all the hotpluggable CPUs
 	for i in $(get_hotplug_cpus); do
-		if [ "$i" != "cpu0" ]; then
-			if ! cpu_is_online $i; then
-				if ! online_cpu $i; then
-					tst_brkm TBROK "$i cannot be onlined"
-				fi
-			fi
-			cpu=$((cpu+1))
-			echo $i
-		else
-			if online_cpu $i; then
-				cpustate=0
+		if ! cpu_is_online $i; then
+			if ! online_cpu $i; then
+				tst_brkm TBROK "$i can not be onlined"
 			fi
 		fi
 	done
 
-	# Now offline all the CPUs
+	# Now offline them
+	cpu=0
 	for i in $(get_hotplug_cpus); do
-		if ! offline_cpu $i; then
-			if [ "x$i" != "xcpu0" ]; then
-				tst_resm TFAIL "Did not offline first CPU (offlined $i instead)"
-				tst_exit
+		cpu=$((cpu + 1))
+
+		# If all the CPUs are hotpluggable, we expect
+		# that the kernel will refuse to offline the last CPU.
+		# If only some of the CPUs are hotpluggable,
+		# they all can be offlined.
+		if [ $cpu -eq $cpus_num ]; then
+			if offline_cpu $i 2> /dev/null; then
+				tst_brkm TFAIL "Have we just offlined the last CPU?"
+			else
+				tst_resm TPASS "System prevented us from offlining the last CPU - $i"
+			fi
+		else
+			if ! offline_cpu $i; then
+				tst_brkm TFAIL "Could not offline $i"
 			fi
 		fi
 	done

@@ -92,6 +100,6 @@ until [ $LOOP_COUNT -gt $HOTPLUG04_LOOPS ]; do
 
 done
 
-tst_resm TPASS "Successfully offlined first CPU, $i"
+tst_resm TPASS "Success"
 
 tst_exit