Merge branch 'tip/tracing/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into tracing/urgent

1 files changed, 690 insertions, 0 deletions

diff --git a/kernel/padata.c b/kernel/padata.c
new file mode 100644
index 000000000000..6f9bcb8313d6
--- /dev/null
+++ b/kernel/padata.c
@@ -0,0 +1,690 @@
+/*
+ * padata.c - generic interface to process data streams in parallel
+ *
+ * Copyright (C) 2008, 2009 secunet Security Networks AG
+ * Copyright (C) 2008, 2009 Steffen Klassert <steffen.klassert@secunet.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include <linux/module.h>
+#include <linux/cpumask.h>
+#include <linux/err.h>
+#include <linux/cpu.h>
+#include <linux/padata.h>
+#include <linux/mutex.h>
+#include <linux/sched.h>
+#include <linux/rcupdate.h>
+
+#define MAX_SEQ_NR INT_MAX - NR_CPUS
+#define MAX_OBJ_NUM 10000 * NR_CPUS
+
+static int padata_index_to_cpu(struct parallel_data *pd, int cpu_index)
+{
+        int cpu, target_cpu;
+
+        target_cpu = cpumask_first(pd->cpumask);
+        for (cpu = 0; cpu < cpu_index; cpu++)
+                target_cpu = cpumask_next(target_cpu, pd->cpumask);
+
+        return target_cpu;
+}
+
+static int padata_cpu_hash(struct padata_priv *padata)
+{
+        int cpu_index;
+        struct parallel_data *pd;
+
+        pd =  padata->pd;
+
+        /*
+         * Hash the sequence numbers to the cpus by taking
+         * seq_nr mod. number of cpus in use.
+         */
+        cpu_index =  padata->seq_nr % cpumask_weight(pd->cpumask);
+
+        return padata_index_to_cpu(pd, cpu_index);
+}
+
+static void padata_parallel_worker(struct work_struct *work)
+{
+        struct padata_queue *queue;
+        struct parallel_data *pd;
+        struct padata_instance *pinst;
+        LIST_HEAD(local_list);
+
+        local_bh_disable();
+        queue = container_of(work, struct padata_queue, pwork);
+        pd = queue->pd;
+        pinst = pd->pinst;
+
+        spin_lock(&queue->parallel.lock);
+        list_replace_init(&queue->parallel.list, &local_list);
+        spin_unlock(&queue->parallel.lock);
+
+        while (!list_empty(&local_list)) {
+                struct padata_priv *padata;
+
+                padata = list_entry(local_list.next,
+                                    struct padata_priv, list);
+
+                list_del_init(&padata->list);
+
+                padata->parallel(padata);
+        }
+
+        local_bh_enable();
+}
+
+/*
+ * padata_do_parallel - padata parallelization function
+ *
+ * @pinst: padata instance
+ * @padata: object to be parallelized
+ * @cb_cpu: cpu the serialization callback function will run on,
+ *          must be in the cpumask of padata.
+ *
+ * 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)
+{
+        int target_cpu, err;
+        struct padata_queue *queue;
+        struct parallel_data *pd;
+
+        rcu_read_lock_bh();
+
+        pd = rcu_dereference(pinst->pd);
+
+        err = 0;
+        if (!(pinst->flags & PADATA_INIT))
+                goto out;
+
+        err =  -EBUSY;
+        if ((pinst->flags & PADATA_RESET))
+                goto out;
+
+        if (atomic_read(&pd->refcnt) >= MAX_OBJ_NUM)
+                goto out;
+
+        err = -EINVAL;
+        if (!cpumask_test_cpu(cb_cpu, pd->cpumask))
+                goto out;
+
+        err = -EINPROGRESS;
+        atomic_inc(&pd->refcnt);
+        padata->pd = pd;
+        padata->cb_cpu = cb_cpu;
+
+        if (unlikely(atomic_read(&pd->seq_nr) == pd->max_seq_nr))
+                atomic_set(&pd->seq_nr, -1);
+
+        padata->seq_nr = atomic_inc_return(&pd->seq_nr);
+
+        target_cpu = padata_cpu_hash(padata);
+        queue = per_cpu_ptr(pd->queue, target_cpu);
+
+        spin_lock(&queue->parallel.lock);
+        list_add_tail(&padata->list, &queue->parallel.list);
+        spin_unlock(&queue->parallel.lock);
+
+        queue_work_on(target_cpu, pinst->wq, &queue->pwork);
+
+out:
+        rcu_read_unlock_bh();
+
+        return err;
+}
+EXPORT_SYMBOL(padata_do_parallel);
+
+static struct padata_priv *padata_get_next(struct parallel_data *pd)
+{
+        int cpu, num_cpus, empty, calc_seq_nr;
+        int seq_nr, next_nr, overrun, next_overrun;
+        struct padata_queue *queue, *next_queue;
+        struct padata_priv *padata;
+        struct padata_list *reorder;
+
+        empty = 0;
+        next_nr = -1;
+        next_overrun = 0;
+        next_queue = NULL;
+
+        num_cpus = cpumask_weight(pd->cpumask);
+
+        for_each_cpu(cpu, pd->cpumask) {
+                queue = per_cpu_ptr(pd->queue, cpu);
+                reorder = &queue->reorder;
+
+                /*
+                 * Calculate the seq_nr of the object that should be
+                 * next in this queue.
+                 */
+                overrun = 0;
+                calc_seq_nr = (atomic_read(&queue->num_obj) * num_cpus)
+                               + queue->cpu_index;
+
+                if (unlikely(calc_seq_nr > pd->max_seq_nr)) {
+                        calc_seq_nr = calc_seq_nr - pd->max_seq_nr - 1;
+                        overrun = 1;
+                }
+
+                if (!list_empty(&reorder->list)) {
+                        padata = list_entry(reorder->list.next,
+                                            struct padata_priv, list);
+
+                        seq_nr  = padata->seq_nr;
+                        BUG_ON(calc_seq_nr != seq_nr);
+                } else {
+                        seq_nr = calc_seq_nr;
+                        empty++;
+                }
+
+                if (next_nr < 0 || seq_nr < next_nr
+                    || (next_overrun && !overrun)) {
+                        next_nr = seq_nr;
+                        next_overrun = overrun;
+                        next_queue = queue;
+                }
+        }
+