[PATCH -mm 1/2] Support for freezeable workqueues

Rafael J. Wysocki
2006-11-16T08:22:38Z

Make it possible to create a workqueue the worker thread of which will be
frozen during suspend, along with other kernel threads.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
---
include/linux/workqueue.h | 8 +++++---
kernel/workqueue.c | 20 ++++++++++++++------
2 files changed, 19 insertions(+), 9 deletions(-)

Index: linux-2.6.19-rc5-mm2/include/linux/workqueue.h
===================================================================
--- linux-2.6.19-rc5-mm2.orig/include/linux/workqueue.h
+++ linux-2.6.19-rc5-mm2/include/linux/workqueue.h
@@ -55,9 +55,11 @@ struct execute_work {
} while (0)

extern struct workqueue_struct *__create_workqueue(const char *name,
- int singlethread);
-#define create_workqueue(name) __create_workqueue((name), 0)
-#define create_singlethread_workqueue(name) __create_workqueue((name), 1)
+ int singlethread,
+ int freezeable);
+#define create_workqueue(name) __create_workqueue((name), 0, 0)
+#define create_freezeable_workqueue(name) __create_workqueue((name), 0, 1)
+#define create_singlethread_workqueue(name) __create_workqueue((name), 1, 0)

extern void destroy_workqueue(struct workqueue_struct *wq);

Index: linux-2.6.19-rc5-mm2/kernel/workqueue.c
===================================================================
--- linux-2.6.19-rc5-mm2.orig/kernel/workqueue.c
+++ linux-2.6.19-rc5-mm2/kernel/workqueue.c
@@ -31,6 +31,7 @@
#include <linux/mempolicy.h>
#include <linux/kallsyms.h>
#include <linux/debug_locks.h>
+#include <linux/freezer.h>

/*
* The per-CPU workqueue (if single thread, we always use the first
@@ -57,6 +58,8 @@ struct cpu_workqueue_struct {
struct task_struct *thread;

int run_depth; /* Detect run_workqueue() recursion depth */
+
+ int freezeable; /* Freeze the thread during suspend */
} ____cacheline_aligned;

/*
@@ -251,7 +254,8 @@ static int worker_thread(void *__cwq)
struct k_sigaction sa;
sigset_t blocked;

- current->flags |= PF_NOFREEZE;
+ if (!cwq->freezeable)
+ current->flags |= PF_NOFREEZE;

set_user_nice(current, -5);

@@ -274,6 +278,9 @@ static int worker_thread(void *__cwq)

set_current_state(TASK_INTERRUPTIBLE);
while (!kthread_should_stop()) {
+ if (cwq->freezeable)
+ try_to_freeze();
+
add_wait_queue(&cwq->more_work, &wait);
if (list_empty(&cwq->worklist))
schedule();
@@ -350,7 +357,7 @@ void fastcall flush_workqueue(struct wor
EXPORT_SYMBOL_GPL(flush_workqueue);

static struct task_struct *create_workqueue_thread(struct workqueue_struct *wq,
- int cpu)
+ int cpu, int freezeable)
{
struct cpu_workqueue_struct *cwq = per_cpu_ptr(wq->cpu_wq, cpu);
struct task_struct *p;
@@ -360,6 +367,7 @@ static struct task_struct *create_workqu
cwq->thread = NULL;
cwq->insert_sequence = 0;
cwq->remove_sequence = 0;
+ cwq->freezeable = freezeable;
INIT_LIST_HEAD(&cwq->worklist);
init_waitqueue_head(&cwq->more_work);
init_waitqueue_head(&cwq->work_done);
@@ -375,7 +383,7 @@ static struct task_struct *create_workqu
}

struct workqueue_struct *__create_workqueue(const char *name,
- int singlethread)
+ int singlethread, int freezeable)
{
int cpu, destroy = 0;
struct workqueue_struct *wq;
@@ -395,7 +403,7 @@ struct workqueue_struct *__create_workqu
mutex_lock(&workqueue_mutex);
if (singlethread) {
INIT_LIST_HEAD(&wq->list);
- p = create_workqueue_thread(wq, singlethread_cpu);
+ p = create_workqueue_thread(wq, singlethread_cpu, freezeable);
if (!p)
destroy = 1;
else
@@ -403,7 +411,7 @@ struct workqueue_struct *__create_workqu
} else {
list_add(&wq->list, &workqueues);
for_each_online_cpu(cpu) {
- p = create_workqueue_thread(wq, cpu);
+ p = create_workqueue_thread(wq, cpu, freezeable);
if (p) {
kthread_bind(p, cpu);
wake_up_process(p);
@@ -657,7 +665,7 @@ static int __devinit workqueue_cpu_callb
mutex_lock(&workqueue_mutex);
/* Create a new workqueue thread for it. */
list_for_each_entry(wq, &workqueues, list) {
- if (!create_workqueue_thread(wq, hotcpu)) {
+ if (!create_workqueue_thread(wq, hotcpu, 0)) {
printk("workqueue for %i failed\n", hotcpu);
return NOTIFY_BAD;
}