aboutsummaryrefslogtreecommitdiff
path: root/kernel/stop_machine.c
diff options
context:
space:
mode:
authorHeiko Carstens <heiko.carstens@de.ibm.com>2008-10-22 10:00:26 -0500
committerRusty Russell <rusty@rustcorp.com.au>2008-10-22 10:00:26 +1100
commit8163bcac779f62c6bf847caed9bce905db0693fb (patch)
tree8fcf397c504fadbebecde09901aacef06b4551d8 /kernel/stop_machine.c
parentc9583e55fa2b08a230c549bd1e3c0bde6c50d9cc (diff)
downloadlinux-linaro-8163bcac779f62c6bf847caed9bce905db0693fb.tar.gz
stop_machine: fix error code handling on multiple cpus
Using |= for updating a value which might be updated on several cpus concurrently will not always work since we need to make sure that the update happens atomically. To fix this just use a write if the called function returns an error code on a cpu. We end up writing the error code of an arbitrary cpu if multiple ones fail but that should be sufficient. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Diffstat (limited to 'kernel/stop_machine.c')
-rw-r--r--kernel/stop_machine.c9
1 files changed, 6 insertions, 3 deletions
diff --git a/kernel/stop_machine.c b/kernel/stop_machine.c
index 0e688c6a1a6..8aff79d90dd 100644
--- a/kernel/stop_machine.c
+++ b/kernel/stop_machine.c
@@ -66,6 +66,7 @@ static void stop_cpu(struct work_struct *unused)
enum stopmachine_state curstate = STOPMACHINE_NONE;
struct stop_machine_data *smdata = &idle;
int cpu = smp_processor_id();
+ int err;
if (!active_cpus) {
if (cpu == first_cpu(cpu_online_map))
@@ -86,9 +87,11 @@ static void stop_cpu(struct work_struct *unused)
hard_irq_disable();
break;
case STOPMACHINE_RUN:
- /* |= allows error detection if functions on
- * multiple CPUs. */
- smdata->fnret |= smdata->fn(smdata->data);
+ /* On multiple CPUs only a single error code
+ * is needed to tell that something failed. */
+ err = smdata->fn(smdata->data);
+ if (err)
+ smdata->fnret = err;
break;
default:
break;