path: root/ipc
diff options
authorDavid Howells <>2006-11-22 14:55:48 +0000
committerDavid Howells <>2006-11-22 14:55:48 +0000
commit65f27f38446e1976cc98fd3004b110fedcddd189 (patch)
tree68f8be93feae31dfa018c22db392a05546b63ee1 /ipc
parent365970a1ea76d81cb1ad2f652acb605f06dae256 (diff)
WorkStruct: Pass the work_struct pointer instead of context data
Pass the work_struct pointer to the work function rather than context data. The work function can use container_of() to work out the data. For the cases where the container of the work_struct may go away the moment the pending bit is cleared, it is made possible to defer the release of the structure by deferring the clearing of the pending bit. To make this work, an extra flag is introduced into the management side of the work_struct. This governs auto-release of the structure upon execution. Ordinarily, the work queue executor would release the work_struct for further scheduling or deallocation by clearing the pending bit prior to jumping to the work function. This means that, unless the driver makes some guarantee itself that the work_struct won't go away, the work function may not access anything else in the work_struct or its container lest they be deallocated.. This is a problem if the auxiliary data is taken away (as done by the last patch). However, if the pending bit is *not* cleared before jumping to the work function, then the work function *may* access the work_struct and its container with no problems. But then the work function must itself release the work_struct by calling work_release(). In most cases, automatic release is fine, so this is the default. Special initiators exist for the non-auto-release case (ending in _NAR). Signed-Off-By: David Howells <>
Diffstat (limited to 'ipc')
1 files changed, 6 insertions, 1 deletions
diff --git a/ipc/util.c b/ipc/util.c
index cd8bb14a431f..a9b7a227b8d4 100644
--- a/ipc/util.c
+++ b/ipc/util.c
@@ -514,6 +514,11 @@ void ipc_rcu_getref(void *ptr)
container_of(ptr, struct ipc_rcu_hdr, data)->refcount++;
+static void ipc_do_vfree(struct work_struct *work)
+ vfree(container_of(work, struct ipc_rcu_sched, work));
* ipc_schedule_free - free ipc + rcu space
* @head: RCU callback structure for queued work
@@ -528,7 +533,7 @@ static void ipc_schedule_free(struct rcu_head *head)
struct ipc_rcu_sched *sched =
container_of(&(grace->data[0]), struct ipc_rcu_sched, data[0]);
- INIT_WORK(&sched->work, vfree, sched);
+ INIT_WORK(&sched->work, ipc_do_vfree);