datapath/linux/compat/include/linux/workqueue.h

   1 #ifndef __LINUX_WORKQUEUE_WRAPPER_H
   2 #define __LINUX_WORKQUEUE_WRAPPER_H 1
   3
   4 #include_next <linux/workqueue.h>
   5
   6 #include <linux/version.h>
   7 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,23)
   8
   9 /* Older kernels have an implementation of work queues with some very bad
  10  * characteristics when trying to cancel work (potential deadlocks, use after
  11  * free, etc.  Here we directly use timers instead for delayed work.  It's not
  12  * optimal but it is better than the alternative.  Note that work queues
  13  * normally run in process context but this will cause them to operate in
  14  * softirq context.
  15  */
  16
  17 #include <linux/timer.h>
  18
  19 #undef DECLARE_DELAYED_WORK
  20 #define DECLARE_DELAYED_WORK(n, f) \
  21         struct timer_list n = TIMER_INITIALIZER((void (*)(unsigned long))f, 0, 0)
  22
  23 #define schedule_delayed_work rpl_schedule_delayed_work
  24 static inline int schedule_delayed_work(struct timer_list *timer, unsigned long delay)
  25 {
  26         if (timer_pending(timer))
  27                 return 0;
  28
  29         mod_timer(timer, jiffies + delay);
  30         return 1;
  31 }
  32
  33 #define cancel_delayed_work_sync rpl_cancel_delayed_work_sync
  34 static inline int cancel_delayed_work_sync(struct timer_list *timer)
  35 {
  36         return del_timer_sync(timer);
  37 }
  38
  39 #endif /* kernel version < 2.6.23 */
  40
  41 #endif