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padata: Generic parallelization/serialization interface
This patch introduces an interface to process data objects in parallel. The parallelized objects return after serialization in the same order as they were before the parallelization. Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This commit is contained in:
Steffen Klassert
Herbert Xu
parent
863b557a88
commit
16295bec63
4 changed files with 783 additions and 0 deletions
88
include/linux/padata.h
Normal file
88
include/linux/padata.h
Normal file
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@ -0,0 +1,88 @@
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/*
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* padata.h - header for the padata parallelization interface
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*
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* Copyright (C) 2008, 2009 secunet Security Networks AG
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* Copyright (C) 2008, 2009 Steffen Klassert <steffen.klassert@secunet.com>
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms and conditions of the GNU General Public License,
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* version 2, as published by the Free Software Foundation.
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*
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* This program is distributed in the hope it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
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* more details.
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*
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* You should have received a copy of the GNU General Public License along with
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* this program; if not, write to the Free Software Foundation, Inc.,
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* 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
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*/
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#ifndef PADATA_H
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#define PADATA_H
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#include <linux/workqueue.h>
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#include <linux/spinlock.h>
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#include <linux/list.h>
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struct padata_priv {
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struct list_head list;
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struct parallel_data *pd;
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int cb_cpu;
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int seq_nr;
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int info;
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void (*parallel)(struct padata_priv *padata);
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void (*serial)(struct padata_priv *padata);
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};
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struct padata_list {
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struct list_head list;
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spinlock_t lock;
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};
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struct padata_queue {
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struct padata_list parallel;
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struct padata_list reorder;
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struct padata_list serial;
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struct work_struct pwork;
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struct work_struct swork;
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struct parallel_data *pd;
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atomic_t num_obj;
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int cpu_index;
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};
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struct parallel_data {
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struct padata_instance *pinst;
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struct padata_queue *queue;
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atomic_t seq_nr;
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atomic_t reorder_objects;
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atomic_t refcnt;
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unsigned int max_seq_nr;
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cpumask_var_t cpumask;
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spinlock_t lock;
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};
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struct padata_instance {
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struct notifier_block cpu_notifier;
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struct workqueue_struct *wq;
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struct parallel_data *pd;
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cpumask_var_t cpumask;
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struct mutex lock;
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u8 flags;
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#define PADATA_INIT 1
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#define PADATA_RESET 2
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};
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extern struct padata_instance *padata_alloc(const struct cpumask *cpumask,
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struct workqueue_struct *wq);
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extern void padata_free(struct padata_instance *pinst);
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extern int padata_do_parallel(struct padata_instance *pinst,
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struct padata_priv *padata, int cb_cpu);
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extern void padata_do_serial(struct padata_priv *padata);
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extern int padata_set_cpumask(struct padata_instance *pinst,
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cpumask_var_t cpumask);
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extern int padata_add_cpu(struct padata_instance *pinst, int cpu);
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extern int padata_remove_cpu(struct padata_instance *pinst, int cpu);
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extern void padata_start(struct padata_instance *pinst);
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extern void padata_stop(struct padata_instance *pinst);
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#endif
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@ -1252,4 +1252,8 @@ source "block/Kconfig"
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config PREEMPT_NOTIFIERS
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bool
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config PADATA
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depends on SMP
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bool
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source "kernel/Kconfig.locks"
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@ -100,6 +100,7 @@ obj-$(CONFIG_SLOW_WORK_DEBUG) += slow-work-debugfs.o
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obj-$(CONFIG_PERF_EVENTS) += perf_event.o
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obj-$(CONFIG_HAVE_HW_BREAKPOINT) += hw_breakpoint.o
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obj-$(CONFIG_USER_RETURN_NOTIFIER) += user-return-notifier.o
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obj-$(CONFIG_PADATA) += padata.o
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ifneq ($(CONFIG_SCHED_OMIT_FRAME_POINTER),y)
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# According to Alan Modra <alan@linuxcare.com.au>, the -fno-omit-frame-pointer is
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690
kernel/padata.c
Normal file
690
kernel/padata.c
Normal file
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@ -0,0 +1,690 @@
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/*
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* padata.c - generic interface to process data streams in parallel
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*
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* Copyright (C) 2008, 2009 secunet Security Networks AG
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* Copyright (C) 2008, 2009 Steffen Klassert <steffen.klassert@secunet.com>
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms and conditions of the GNU General Public License,
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* version 2, as published by the Free Software Foundation.
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*
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* This program is distributed in the hope it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
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* more details.
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*
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* You should have received a copy of the GNU General Public License along with
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* this program; if not, write to the Free Software Foundation, Inc.,
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* 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
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*/
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#include <linux/module.h>
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#include <linux/cpumask.h>
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#include <linux/err.h>
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#include <linux/cpu.h>
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#include <linux/padata.h>
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#include <linux/mutex.h>
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#include <linux/sched.h>
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#include <linux/rcupdate.h>
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#define MAX_SEQ_NR INT_MAX - NR_CPUS
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#define MAX_OBJ_NUM 10000 * NR_CPUS
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static int padata_index_to_cpu(struct parallel_data *pd, int cpu_index)
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{
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int cpu, target_cpu;
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target_cpu = cpumask_first(pd->cpumask);
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for (cpu = 0; cpu < cpu_index; cpu++)
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target_cpu = cpumask_next(target_cpu, pd->cpumask);
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return target_cpu;
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}
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static int padata_cpu_hash(struct padata_priv *padata)
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{
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int cpu_index;
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struct parallel_data *pd;
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pd = padata->pd;
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/*
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* Hash the sequence numbers to the cpus by taking
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* seq_nr mod. number of cpus in use.
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*/
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cpu_index = padata->seq_nr % cpumask_weight(pd->cpumask);
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return padata_index_to_cpu(pd, cpu_index);
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}
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static void padata_parallel_worker(struct work_struct *work)
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{
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struct padata_queue *queue;
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struct parallel_data *pd;
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struct padata_instance *pinst;
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LIST_HEAD(local_list);
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local_bh_disable();
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queue = container_of(work, struct padata_queue, pwork);
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pd = queue->pd;
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pinst = pd->pinst;
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spin_lock(&queue->parallel.lock);
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list_replace_init(&queue->parallel.list, &local_list);
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spin_unlock(&queue->parallel.lock);
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while (!list_empty(&local_list)) {
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struct padata_priv *padata;
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padata = list_entry(local_list.next,
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struct padata_priv, list);
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list_del_init(&padata->list);
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padata->parallel(padata);
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}
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local_bh_enable();
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}
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/*
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* padata_do_parallel - padata parallelization function
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*
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* @pinst: padata instance
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* @padata: object to be parallelized
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* @cb_cpu: cpu the serialization callback function will run on,
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* must be in the cpumask of padata.
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*
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* The parallelization callback function will run with BHs off.
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* Note: Every object which is parallelized by padata_do_parallel
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* must be seen by padata_do_serial.
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*/
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int padata_do_parallel(struct padata_instance *pinst,
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struct padata_priv *padata, int cb_cpu)
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{
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int target_cpu, err;
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struct padata_queue *queue;
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struct parallel_data *pd;
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rcu_read_lock_bh();
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pd = rcu_dereference(pinst->pd);
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err = 0;
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if (!(pinst->flags & PADATA_INIT))
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goto out;
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err = -EBUSY;
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if ((pinst->flags & PADATA_RESET))
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goto out;
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if (atomic_read(&pd->refcnt) >= MAX_OBJ_NUM)
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goto out;
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err = -EINVAL;
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if (!cpumask_test_cpu(cb_cpu, pd->cpumask))
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goto out;
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err = -EINPROGRESS;
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atomic_inc(&pd->refcnt);
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padata->pd = pd;
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padata->cb_cpu = cb_cpu;
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if (unlikely(atomic_read(&pd->seq_nr) == pd->max_seq_nr))
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atomic_set(&pd->seq_nr, -1);
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padata->seq_nr = atomic_inc_return(&pd->seq_nr);
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target_cpu = padata_cpu_hash(padata);
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queue = per_cpu_ptr(pd->queue, target_cpu);
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spin_lock(&queue->parallel.lock);
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list_add_tail(&padata->list, &queue->parallel.list);
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spin_unlock(&queue->parallel.lock);
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queue_work_on(target_cpu, pinst->wq, &queue->pwork);
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out:
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rcu_read_unlock_bh();
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return err;
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}
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EXPORT_SYMBOL(padata_do_parallel);
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static struct padata_priv *padata_get_next(struct parallel_data *pd)
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{
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int cpu, num_cpus, empty, calc_seq_nr;
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int seq_nr, next_nr, overrun, next_overrun;
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struct padata_queue *queue, *next_queue;
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struct padata_priv *padata;
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struct padata_list *reorder;
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empty = 0;
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next_nr = -1;
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next_overrun = 0;
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next_queue = NULL;
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num_cpus = cpumask_weight(pd->cpumask);
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for_each_cpu(cpu, pd->cpumask) {
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queue = per_cpu_ptr(pd->queue, cpu);
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reorder = &queue->reorder;
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/*
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* Calculate the seq_nr of the object that should be
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* next in this queue.
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*/
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overrun = 0;
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calc_seq_nr = (atomic_read(&queue->num_obj) * num_cpus)
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+ queue->cpu_index;
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if (unlikely(calc_seq_nr > pd->max_seq_nr)) {
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calc_seq_nr = calc_seq_nr - pd->max_seq_nr - 1;
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overrun = 1;
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}
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if (!list_empty(&reorder->list)) {
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padata = list_entry(reorder->list.next,
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struct padata_priv, list);
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seq_nr = padata->seq_nr;
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BUG_ON(calc_seq_nr != seq_nr);
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} else {
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seq_nr = calc_seq_nr;
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empty++;
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}
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if (next_nr < 0 || seq_nr < next_nr
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|| (next_overrun && !overrun)) {
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next_nr = seq_nr;
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next_overrun = overrun;
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next_queue = queue;
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}
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}
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padata = NULL;
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if (empty == num_cpus)
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goto out;
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reorder = &next_queue->reorder;
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if (!list_empty(&reorder->list)) {
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padata = list_entry(reorder->list.next,
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struct padata_priv, list);
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if (unlikely(next_overrun)) {
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for_each_cpu(cpu, pd->cpumask) {
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queue = per_cpu_ptr(pd->queue, cpu);
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atomic_set(&queue->num_obj, 0);
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}
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}
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spin_lock(&reorder->lock);
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list_del_init(&padata->list);
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atomic_dec(&pd->reorder_objects);
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spin_unlock(&reorder->lock);
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atomic_inc(&next_queue->num_obj);
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goto out;
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}
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if (next_nr % num_cpus == next_queue->cpu_index) {
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padata = ERR_PTR(-ENODATA);
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goto out;
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}
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padata = ERR_PTR(-EINPROGRESS);
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out:
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return padata;
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}
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static void padata_reorder(struct parallel_data *pd)
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{
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struct padata_priv *padata;
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struct padata_queue *queue;
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struct padata_instance *pinst = pd->pinst;
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try_again:
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if (!spin_trylock_bh(&pd->lock))
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goto out;
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while (1) {
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padata = padata_get_next(pd);
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if (!padata || PTR_ERR(padata) == -EINPROGRESS)
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break;
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if (PTR_ERR(padata) == -ENODATA) {
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spin_unlock_bh(&pd->lock);
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goto out;
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}
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queue = per_cpu_ptr(pd->queue, padata->cb_cpu);
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spin_lock(&queue->serial.lock);
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list_add_tail(&padata->list, &queue->serial.list);
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spin_unlock(&queue->serial.lock);
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queue_work_on(padata->cb_cpu, pinst->wq, &queue->swork);
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}
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spin_unlock_bh(&pd->lock);
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if (atomic_read(&pd->reorder_objects))
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goto try_again;
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out:
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return;
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}
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static void padata_serial_worker(struct work_struct *work)
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{
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struct padata_queue *queue;
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struct parallel_data *pd;
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LIST_HEAD(local_list);
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local_bh_disable();
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queue = container_of(work, struct padata_queue, swork);
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pd = queue->pd;
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spin_lock(&queue->serial.lock);
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list_replace_init(&queue->serial.list, &local_list);
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spin_unlock(&queue->serial.lock);
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while (!list_empty(&local_list)) {
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struct padata_priv *padata;
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padata = list_entry(local_list.next,
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struct padata_priv, list);
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list_del_init(&padata->list);
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padata->serial(padata);
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atomic_dec(&pd->refcnt);
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}
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local_bh_enable();
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}
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/*
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* padata_do_serial - padata serialization function
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*
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* @padata: object to be serialized.
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*
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* padata_do_serial must be called for every parallelized object.
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* The serialization callback function will run with BHs off.
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*/
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void padata_do_serial(struct padata_priv *padata)
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{
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int cpu;
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struct padata_queue *queue;
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struct parallel_data *pd;
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pd = padata->pd;
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cpu = get_cpu();
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queue = per_cpu_ptr(pd->queue, cpu);
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spin_lock(&queue->reorder.lock);
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atomic_inc(&pd->reorder_objects);
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list_add_tail(&padata->list, &queue->reorder.list);
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spin_unlock(&queue->reorder.lock);
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put_cpu();
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padata_reorder(pd);
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}
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EXPORT_SYMBOL(padata_do_serial);
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static struct parallel_data *padata_alloc_pd(struct padata_instance *pinst,
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const struct cpumask *cpumask)
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{
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int cpu, cpu_index, num_cpus;
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struct padata_queue *queue;
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struct parallel_data *pd;
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cpu_index = 0;
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pd = kzalloc(sizeof(struct parallel_data), GFP_KERNEL);
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if (!pd)
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goto err;
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pd->queue = alloc_percpu(struct padata_queue);
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if (!pd->queue)
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goto err_free_pd;
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if (!alloc_cpumask_var(&pd->cpumask, GFP_KERNEL))
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goto err_free_queue;
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for_each_possible_cpu(cpu) {
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queue = per_cpu_ptr(pd->queue, cpu);
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queue->pd = pd;
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if (cpumask_test_cpu(cpu, cpumask)
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&& cpumask_test_cpu(cpu, cpu_active_mask)) {
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queue->cpu_index = cpu_index;
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cpu_index++;
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} else
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queue->cpu_index = -1;
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INIT_LIST_HEAD(&queue->reorder.list);
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INIT_LIST_HEAD(&queue->parallel.list);
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INIT_LIST_HEAD(&queue->serial.list);
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spin_lock_init(&queue->reorder.lock);
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spin_lock_init(&queue->parallel.lock);
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spin_lock_init(&queue->serial.lock);
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INIT_WORK(&queue->pwork, padata_parallel_worker);
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INIT_WORK(&queue->swork, padata_serial_worker);
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atomic_set(&queue->num_obj, 0);
|
||||
}
|
||||
|
||||
cpumask_and(pd->cpumask, cpumask, cpu_active_mask);
|
||||
|
||||
num_cpus = cpumask_weight(pd->cpumask);
|
||||
pd->max_seq_nr = (MAX_SEQ_NR / num_cpus) * num_cpus - 1;
|
||||
|
||||
atomic_set(&pd->seq_nr, -1);
|
||||
atomic_set(&pd->reorder_objects, 0);
|
||||
atomic_set(&pd->refcnt, 0);
|
||||
pd->pinst = pinst;
|
||||
spin_lock_init(&pd->lock);
|
||||
|
||||
return pd;
|
||||
|
||||
err_free_queue:
|
||||
free_percpu(pd->queue);
|
||||
err_free_pd:
|
||||
kfree(pd);
|
||||
err:
|
||||
return NULL;
|
||||
}
|
||||
|
||||
static void padata_free_pd(struct parallel_data *pd)
|
||||
{
|
||||
free_cpumask_var(pd->cpumask);
|
||||
free_percpu(pd->queue);
|
||||
kfree(pd);
|
||||
}
|
||||
|
||||
static void padata_replace(struct padata_instance *pinst,
|
||||
struct parallel_data *pd_new)
|
||||
{
|
||||
struct parallel_data *pd_old = pinst->pd;
|
||||
|
||||
pinst->flags |= PADATA_RESET;
|
||||
|
||||
rcu_assign_pointer(pinst->pd, pd_new);
|
||||
|
||||
synchronize_rcu();
|
||||
|
||||
while (atomic_read(&pd_old->refcnt) != 0)
|
||||
yield();
|
||||
|
||||
flush_workqueue(pinst->wq);
|
||||
|
||||
padata_free_pd(pd_old);
|
||||
|
||||
pinst->flags &= ~PADATA_RESET;
|
||||
}
|
||||
|
||||
/*
|
||||
* padata_set_cpumask - set the cpumask that padata should use
|
||||
*
|
||||
* @pinst: padata instance
|
||||
* @cpumask: the cpumask to use
|
||||
*/
|
||||
int padata_set_cpumask(struct padata_instance *pinst,
|
||||
cpumask_var_t cpumask)
|
||||
{
|
||||
struct parallel_data *pd;
|
||||
int err = 0;
|
||||
|
||||
might_sleep();
|
||||
|
||||
mutex_lock(&pinst->lock);
|
||||
|
||||
pd = padata_alloc_pd(pinst, cpumask);
|
||||
if (!pd) {
|
||||
err = -ENOMEM;
|
||||
goto out;
|
||||
}
|
||||
|
||||
cpumask_copy(pinst->cpumask, cpumask);
|
||||
|
||||
padata_replace(pinst, pd);
|
||||
|
||||
out:
|
||||
mutex_unlock(&pinst->lock);
|
||||
|
||||
return err;
|
||||
}
|
||||
EXPORT_SYMBOL(padata_set_cpumask);
|
||||
|
||||
static int __padata_add_cpu(struct padata_instance *pinst, int cpu)
|
||||
{
|
||||
struct parallel_data *pd;
|
||||
|
||||
if (cpumask_test_cpu(cpu, cpu_active_mask)) {
|
||||
pd = padata_alloc_pd(pinst, pinst->cpumask);
|
||||
if (!pd)
|
||||
return -ENOMEM;
|
||||
|
||||
padata_replace(pinst, pd);
|
||||
}
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
/*
|
||||
* padata_add_cpu - add a cpu to the padata cpumask
|
||||
*
|
||||
* @pinst: padata instance
|
||||
* @cpu: cpu to add
|
||||
*/
|
||||
int padata_add_cpu(struct padata_instance *pinst, int cpu)
|
||||
{
|
||||
int err;
|
||||
|
||||
might_sleep();
|
||||
|
||||
mutex_lock(&pinst->lock);
|
||||
|
||||
cpumask_set_cpu(cpu, pinst->cpumask);
|
||||
err = __padata_add_cpu(pinst, cpu);
|
||||
|
||||
mutex_unlock(&pinst->lock);
|
||||
|
||||
return err;
|
||||
}
|
||||
EXPORT_SYMBOL(padata_add_cpu);
|
||||
|
||||
static int __padata_remove_cpu(struct padata_instance *pinst, int cpu)
|
||||
{
|
||||
struct parallel_data *pd;
|
||||
|
||||
if (cpumask_test_cpu(cpu, cpu_online_mask)) {
|
||||
pd = padata_alloc_pd(pinst, pinst->cpumask);
|
||||
if (!pd)
|
||||
return -ENOMEM;
|
||||
|
||||
padata_replace(pinst, pd);
|
||||
}
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
/*
|
||||
* padata_remove_cpu - remove a cpu from the padata cpumask
|
||||
*
|
||||
* @pinst: padata instance
|
||||
* @cpu: cpu to remove
|
||||
*/
|
||||
int padata_remove_cpu(struct padata_instance *pinst, int cpu)
|
||||
{
|
||||
int err;
|
||||
|
||||
might_sleep();
|
||||
|
||||
mutex_lock(&pinst->lock);
|
||||
|
||||
cpumask_clear_cpu(cpu, pinst->cpumask);
|
||||
err = __padata_remove_cpu(pinst, cpu);
|
||||
|
||||
mutex_unlock(&pinst->lock);
|
||||
|
||||
return err;
|
||||
}
|
||||
EXPORT_SYMBOL(padata_remove_cpu);
|
||||
|
||||
/*
|
||||
* padata_start - start the parallel processing
|
||||
*
|
||||
* @pinst: padata instance to start
|
||||
*/
|
||||
void padata_start(struct padata_instance *pinst)
|
||||
{
|
||||
might_sleep();
|
||||
|
||||
mutex_lock(&pinst->lock);
|
||||
pinst->flags |= PADATA_INIT;
|
||||
mutex_unlock(&pinst->lock);
|
||||
}
|
||||
EXPORT_SYMBOL(padata_start);
|
||||
|
||||
/*
|
||||
* padata_stop - stop the parallel processing
|
||||
*
|
||||
* @pinst: padata instance to stop
|
||||
*/
|
||||
void padata_stop(struct padata_instance *pinst)
|
||||
{
|
||||
might_sleep();
|
||||
|
||||
mutex_lock(&pinst->lock);
|
||||
pinst->flags &= ~PADATA_INIT;
|
||||
mutex_unlock(&pinst->lock);
|
||||
}
|
||||
EXPORT_SYMBOL(padata_stop);
|
||||
|
||||
static int __cpuinit padata_cpu_callback(struct notifier_block *nfb,
|
||||
unsigned long action, void *hcpu)
|
||||
{
|
||||
int err;
|
||||
struct padata_instance *pinst;
|
||||
int cpu = (unsigned long)hcpu;
|
||||
|
||||
pinst = container_of(nfb, struct padata_instance, cpu_notifier);
|
||||
|
||||
switch (action) {
|
||||
case CPU_ONLINE:
|
||||
case CPU_ONLINE_FROZEN:
|
||||
if (!cpumask_test_cpu(cpu, pinst->cpumask))
|
||||
break;
|
||||
mutex_lock(&pinst->lock);
|
||||
err = __padata_add_cpu(pinst, cpu);
|
||||
mutex_unlock(&pinst->lock);
|
||||
if (err)
|
||||
return NOTIFY_BAD;
|
||||
break;
|
||||
|
||||
case CPU_DOWN_PREPARE:
|
||||
case CPU_DOWN_PREPARE_FROZEN:
|
||||
if (!cpumask_test_cpu(cpu, pinst->cpumask))
|
||||
break;
|
||||
mutex_lock(&pinst->lock);
|
||||
err = __padata_remove_cpu(pinst, cpu);
|
||||
mutex_unlock(&pinst->lock);
|
||||
if (err)
|
||||
return NOTIFY_BAD;
|
||||
break;
|
||||
|
||||
case CPU_UP_CANCELED:
|
||||
case CPU_UP_CANCELED_FROZEN:
|
||||
if (!cpumask_test_cpu(cpu, pinst->cpumask))
|
||||
break;
|
||||
mutex_lock(&pinst->lock);
|
||||
__padata_remove_cpu(pinst, cpu);
|
||||
mutex_unlock(&pinst->lock);
|
||||
|
||||
case CPU_DOWN_FAILED:
|
||||
case CPU_DOWN_FAILED_FROZEN:
|
||||
if (!cpumask_test_cpu(cpu, pinst->cpumask))
|
||||
break;
|
||||
mutex_lock(&pinst->lock);
|
||||
__padata_add_cpu(pinst, cpu);
|
||||
mutex_unlock(&pinst->lock);
|
||||
}
|
||||
|
||||
return NOTIFY_OK;
|
||||
}
|
||||
|
||||
/*
|
||||
* padata_alloc - allocate and initialize a padata instance
|
||||
*
|
||||
* @cpumask: cpumask that padata uses for parallelization
|
||||
* @wq: workqueue to use for the allocated padata instance
|
||||
*/
|
||||
struct padata_instance *padata_alloc(const struct cpumask *cpumask,
|
||||
struct workqueue_struct *wq)
|
||||
{
|
||||
int err;
|
||||
struct padata_instance *pinst;
|
||||
struct parallel_data *pd;
|
||||
|
||||
pinst = kzalloc(sizeof(struct padata_instance), GFP_KERNEL);
|
||||
if (!pinst)
|
||||
goto err;
|
||||
|
||||
pd = padata_alloc_pd(pinst, cpumask);
|
||||
if (!pd)
|
||||
goto err_free_inst;
|
||||
|
||||
rcu_assign_pointer(pinst->pd, pd);
|
||||
|
||||
pinst->wq = wq;
|
||||
|
||||
cpumask_copy(pinst->cpumask, cpumask);
|
||||
|
||||
pinst->flags = 0;
|
||||
|
||||
pinst->cpu_notifier.notifier_call = padata_cpu_callback;
|
||||
pinst->cpu_notifier.priority = 0;
|
||||
err = register_hotcpu_notifier(&pinst->cpu_notifier);
|
||||
if (err)
|
||||
goto err_free_pd;
|
||||
|
||||
mutex_init(&pinst->lock);
|
||||
|
||||
return pinst;
|
||||
|
||||
err_free_pd:
|
||||
padata_free_pd(pd);
|
||||
err_free_inst:
|
||||
kfree(pinst);
|
||||
err:
|
||||
return NULL;
|
||||
}
|
||||
EXPORT_SYMBOL(padata_alloc);
|
||||
|
||||
/*
|
||||
* padata_free - free a padata instance
|
||||
*
|
||||
* @ padata_inst: padata instance to free
|
||||
*/
|
||||
void padata_free(struct padata_instance *pinst)
|
||||
{
|
||||
padata_stop(pinst);
|
||||
|
||||
synchronize_rcu();
|
||||
|
||||
while (atomic_read(&pinst->pd->refcnt) != 0)
|
||||
yield();
|
||||
|
||||
unregister_hotcpu_notifier(&pinst->cpu_notifier);
|
||||
padata_free_pd(pinst->pd);
|
||||
kfree(pinst);
|
||||
}
|
||||
EXPORT_SYMBOL(padata_free);
|
||||
Loading…
Reference in a new issue