diff options
author | Heiko Carstens <heiko.carstens@de.ibm.com> | 2008-04-30 07:38:36 -0400 |
---|---|---|
committer | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2008-04-30 07:38:44 -0400 |
commit | 0b18d318b80a7f350648ca8f7cc00a2f688104cb (patch) | |
tree | 7a5346faefb67b24f05c00691ca170a6805b0921 /arch/s390 | |
parent | f291e17227cf30432ca7c402220f62e6924dd97d (diff) |
[S390] smp: Fix locking order.
On some smp sysfs store attributes get_online_cpus() may block on
cpu_hotplug.lock, but we hold already smp_cpu_state_mutex. Since the
locking order on cpu hotplug via arch_update_cpu_topology is inverse
this might lead to deadlocks.
So make sure locking order is always the same.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch/s390')
-rw-r--r-- | arch/s390/kernel/smp.c | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c index 0dfa988c1b26..6bb5c050640f 100644 --- a/arch/s390/kernel/smp.c +++ b/arch/s390/kernel/smp.c | |||
@@ -890,8 +890,8 @@ static ssize_t cpu_configure_store(struct sys_device *dev, const char *buf, | |||
890 | if (val != 0 && val != 1) | 890 | if (val != 0 && val != 1) |
891 | return -EINVAL; | 891 | return -EINVAL; |
892 | 892 | ||
893 | mutex_lock(&smp_cpu_state_mutex); | ||
894 | get_online_cpus(); | 893 | get_online_cpus(); |
894 | mutex_lock(&smp_cpu_state_mutex); | ||
895 | rc = -EBUSY; | 895 | rc = -EBUSY; |
896 | if (cpu_online(cpu)) | 896 | if (cpu_online(cpu)) |
897 | goto out; | 897 | goto out; |
@@ -919,8 +919,8 @@ static ssize_t cpu_configure_store(struct sys_device *dev, const char *buf, | |||
919 | break; | 919 | break; |
920 | } | 920 | } |
921 | out: | 921 | out: |
922 | put_online_cpus(); | ||
923 | mutex_unlock(&smp_cpu_state_mutex); | 922 | mutex_unlock(&smp_cpu_state_mutex); |
923 | put_online_cpus(); | ||
924 | return rc ? rc : count; | 924 | return rc ? rc : count; |
925 | } | 925 | } |
926 | static SYSDEV_ATTR(configure, 0644, cpu_configure_show, cpu_configure_store); | 926 | static SYSDEV_ATTR(configure, 0644, cpu_configure_show, cpu_configure_store); |
@@ -1095,8 +1095,8 @@ static ssize_t __ref rescan_store(struct sys_device *dev, | |||
1095 | int cpu; | 1095 | int cpu; |
1096 | int rc; | 1096 | int rc; |
1097 | 1097 | ||
1098 | mutex_lock(&smp_cpu_state_mutex); | ||
1099 | get_online_cpus(); | 1098 | get_online_cpus(); |
1099 | mutex_lock(&smp_cpu_state_mutex); | ||
1100 | newcpus = cpu_present_map; | 1100 | newcpus = cpu_present_map; |
1101 | rc = smp_rescan_cpus(); | 1101 | rc = smp_rescan_cpus(); |
1102 | if (rc) | 1102 | if (rc) |
@@ -1109,8 +1109,8 @@ static ssize_t __ref rescan_store(struct sys_device *dev, | |||
1109 | } | 1109 | } |
1110 | rc = 0; | 1110 | rc = 0; |
1111 | out: | 1111 | out: |
1112 | put_online_cpus(); | ||
1113 | mutex_unlock(&smp_cpu_state_mutex); | 1112 | mutex_unlock(&smp_cpu_state_mutex); |
1113 | put_online_cpus(); | ||
1114 | if (!cpus_empty(newcpus)) | 1114 | if (!cpus_empty(newcpus)) |
1115 | topology_schedule_update(); | 1115 | topology_schedule_update(); |
1116 | return rc ? rc : count; | 1116 | return rc ? rc : count; |
@@ -1139,16 +1139,16 @@ static ssize_t dispatching_store(struct sys_device *dev, const char *buf, | |||
1139 | if (val != 0 && val != 1) | 1139 | if (val != 0 && val != 1) |
1140 | return -EINVAL; | 1140 | return -EINVAL; |
1141 | rc = 0; | 1141 | rc = 0; |
1142 | mutex_lock(&smp_cpu_state_mutex); | ||
1143 | get_online_cpus(); | 1142 | get_online_cpus(); |
1143 | mutex_lock(&smp_cpu_state_mutex); | ||
1144 | if (cpu_management == val) | 1144 | if (cpu_management == val) |
1145 | goto out; | 1145 | goto out; |
1146 | rc = topology_set_cpu_management(val); | 1146 | rc = topology_set_cpu_management(val); |
1147 | if (!rc) | 1147 | if (!rc) |
1148 | cpu_management = val; | 1148 | cpu_management = val; |
1149 | out: | 1149 | out: |
1150 | put_online_cpus(); | ||
1151 | mutex_unlock(&smp_cpu_state_mutex); | 1150 | mutex_unlock(&smp_cpu_state_mutex); |
1151 | put_online_cpus(); | ||
1152 | return rc ? rc : count; | 1152 | return rc ? rc : count; |
1153 | } | 1153 | } |
1154 | static SYSDEV_ATTR(dispatching, 0644, dispatching_show, dispatching_store); | 1154 | static SYSDEV_ATTR(dispatching, 0644, dispatching_show, dispatching_store); |