Revision 73863ab028579ed98c4f1f36d016536b1b415344 authored by Anton Vorontsov on 31 May 2012, 23:26:23 UTC, committed by Linus Torvalds on 01 June 2012, 00:49:29 UTC
Current CPU hotplug code has some task->mm handling issues: 1. Working with task->mm w/o getting mm or grabing the task lock is dangerous as ->mm might disappear (exit_mm() assigns NULL under task_lock(), so tasklist lock is not enough). We can't use get_task_mm()/mmput() pair as mmput() might sleep, so we must take the task lock while handle its mm. 2. Checking for process->mm is not enough because process' main thread may exit or detach its mm via use_mm(), but other threads may still have a valid mm. To fix this we would need to use find_lock_task_mm(), which would walk up all threads and returns an appropriate task (with task lock held). clear_tasks_mm_cpumask() has all the issues fixed, so let's use it. Suggested-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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remoteproc_internal.h
/*
* Remote processor framework
*
* Copyright (C) 2011 Texas Instruments, Inc.
* Copyright (C) 2011 Google, Inc.
*
* Ohad Ben-Cohen <ohad@wizery.com>
* Brian Swetland <swetland@google.com>
*
* This software is licensed under the terms of the GNU General Public
* License version 2, as published by the Free Software Foundation, and
* may be copied, distributed, and modified under those terms.
*
* This program is distributed in the hope that 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.
*/
#ifndef REMOTEPROC_INTERNAL_H
#define REMOTEPROC_INTERNAL_H
#include <linux/irqreturn.h>
struct rproc;
/* from remoteproc_core.c */
void rproc_release(struct kref *kref);
irqreturn_t rproc_vq_interrupt(struct rproc *rproc, int vq_id);
/* from remoteproc_virtio.c */
int rproc_add_virtio_dev(struct rproc_vdev *rvdev, int id);
void rproc_remove_virtio_dev(struct rproc_vdev *rvdev);
/* from remoteproc_debugfs.c */
void rproc_remove_trace_file(struct dentry *tfile);
struct dentry *rproc_create_trace_file(const char *name, struct rproc *rproc,
struct rproc_mem_entry *trace);
void rproc_delete_debug_dir(struct rproc *rproc);
void rproc_create_debug_dir(struct rproc *rproc);
void rproc_init_debugfs(void);
void rproc_exit_debugfs(void);
#endif /* REMOTEPROC_INTERNAL_H */
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