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CRED: Rename is_single_threaded() to is_wq_single_threaded() 

Rename is_single_threaded() to is_wq_single_threaded() so that a new
is_single_threaded() can be created that refers to tasks rather than
waitqueues.

Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: James Morris <jmorris@namei.org>
Signed-off-by: James Morris <jmorris@namei.org>
This commit is contained in:
David Howells 2008-11-14 10:39:21 +11:00 committed by James Morris
parent bb952bb98a
commit 6cc88bc45c
2 changed files with 49 additions and 4 deletions
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8
kernel/workqueue.c
View File

@ -84,21 +84,21 @@ static cpumask_t cpu_singlethread_map __read_mostly;
static cpumask_t cpu_populated_map __read_mostly;
/* If it's single threaded, it isn't in the list of workqueues. */
static inline int is_single_threaded(struct workqueue_struct *wq)
static inline int is_wq_single_threaded(struct workqueue_struct *wq)
{
return wq->singlethread;
}
static const cpumask_t *wq_cpu_map(struct workqueue_struct *wq)
{
return is_single_threaded(wq)
return is_wq_single_threaded(wq)
? &cpu_singlethread_map : &cpu_populated_map;
}
static
struct cpu_workqueue_struct *wq_per_cpu(struct workqueue_struct *wq, int cpu)
{
if (unlikely(is_single_threaded(wq)))
if (unlikely(is_wq_single_threaded(wq)))
cpu = singlethread_cpu;
return per_cpu_ptr(wq->cpu_wq, cpu);
}
@ -769,7 +769,7 @@ static int create_workqueue_thread(struct cpu_workqueue_struct *cwq, int cpu)
{
struct sched_param param = { .sched_priority = MAX_RT_PRIO-1 };
struct workqueue_struct *wq = cwq->wq;
const char *fmt = is_single_threaded(wq) ? "%s" : "%s/%d";
const char *fmt = is_wq_single_threaded(wq) ? "%s" : "%s/%d";
struct task_struct *p;
p = kthread_create(worker_thread, cwq, fmt, wq->name, cpu);

45
lib/is_single_threaded.c Normal file
View File

@ -0,0 +1,45 @@
/* Function to determine if a thread group is single threaded or not
*
* Copyright (C) 2008 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
* - Derived from security/selinux/hooks.c
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public Licence
* as published by the Free Software Foundation; either version
* 2 of the Licence, or (at your option) any later version.
*/
#include <linux/sched.h>
/**
* is_single_threaded - Determine if a thread group is single-threaded or not
* @p: A task in the thread group in question
*
* This returns true if the thread group to which a task belongs is single
* threaded, false if it is not.
*/
bool is_single_threaded(struct task_struct *p)
{
struct task_struct *g, *t;
struct mm_struct *mm = p->mm;
if (atomic_read(&p->signal->count) != 1)
goto no;
if (atomic_read(&p->mm->mm_users) != 1) {
read_lock(&tasklist_lock);
do_each_thread(g, t) {
if (t->mm == mm && t != p)
goto no_unlock;
} while_each_thread(g, t);
read_unlock(&tasklist_lock);
}
return true;
no_unlock:
read_unlock(&tasklist_lock);
no:
return false;
}