diff options
Diffstat (limited to 'kernel/padata.c')
| -rw-r--r-- | kernel/padata.c | 27 |
1 files changed, 20 insertions, 7 deletions
diff --git a/kernel/padata.c b/kernel/padata.c index 58728cd7f40c..9a17922ec436 100644 --- a/kernel/padata.c +++ b/kernel/padata.c @@ -94,17 +94,19 @@ static void padata_parallel_worker(struct work_struct *parallel_work) * * @pinst: padata instance * @padata: object to be parallelized - * @cb_cpu: cpu the serialization callback function will run on, - * must be in the serial cpumask of padata(i.e. cpumask.cbcpu). + * @cb_cpu: pointer to the CPU that the serialization callback function should + * run on. If it's not in the serial cpumask of @pinst + * (i.e. cpumask.cbcpu), this function selects a fallback CPU and if + * none found, returns -EINVAL. * * The parallelization callback function will run with BHs off. * Note: Every object which is parallelized by padata_do_parallel * must be seen by padata_do_serial. */ int padata_do_parallel(struct padata_instance *pinst, - struct padata_priv *padata, int cb_cpu) + struct padata_priv *padata, int *cb_cpu) { - int target_cpu, err; + int i, cpu, cpu_index, target_cpu, err; struct padata_parallel_queue *queue; struct parallel_data *pd; @@ -116,8 +118,19 @@ int padata_do_parallel(struct padata_instance *pinst, if (!(pinst->flags & PADATA_INIT) || pinst->flags & PADATA_INVALID) goto out; - if (!cpumask_test_cpu(cb_cpu, pd->cpumask.cbcpu)) - goto out; + if (!cpumask_test_cpu(*cb_cpu, pd->cpumask.cbcpu)) { + if (!cpumask_weight(pd->cpumask.cbcpu)) + goto out; + + /* Select an alternate fallback CPU and notify the caller. */ + cpu_index = *cb_cpu % cpumask_weight(pd->cpumask.cbcpu); + + cpu = cpumask_first(pd->cpumask.cbcpu); + for (i = 0; i < cpu_index; i++) + cpu = cpumask_next(cpu, pd->cpumask.cbcpu); + + *cb_cpu = cpu; + } err = -EBUSY; if ((pinst->flags & PADATA_RESET)) @@ -129,7 +142,7 @@ int padata_do_parallel(struct padata_instance *pinst, err = 0; atomic_inc(&pd->refcnt); padata->pd = pd; - padata->cb_cpu = cb_cpu; + padata->cb_cpu = *cb_cpu; target_cpu = padata_cpu_hash(pd); padata->cpu = target_cpu; |