The patch titled
Task watchers: register per-task semundo watcher
has been removed from the -mm tree. Its filename is
task-watchers-register-per-task-semundo-watcher.patch
This patch was dropped because it was nacked by the maintainer
------------------------------------------------------
Subject: Task watchers: register per-task semundo watcher
From: Matt Helsley <matthltc@xxxxxxxxxx>
This patch switches semundo from using the global task_watchers notifier chain
to a per-task notifier chain. In the case where a task does not use SysV
semaphores this would save a call to exit_sem().
Based off Jes Sorensen's patch implementing this with task_notifiers.
Signed-off-by: Matt Helsley <matthltc@xxxxxxxxxx>
Cc: Jes Sorensen <jes@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---
ipc/sem.c | 23 ++++++++++++++++-------
1 file changed, 16 insertions(+), 7 deletions(-)
diff -puN ipc/sem.c~task-watchers-register-per-task-semundo-watcher ipc/sem.c
--- a/ipc/sem.c~task-watchers-register-per-task-semundo-watcher
+++ a/ipc/sem.c
@@ -135,10 +135,6 @@ static int sem_undo_task_exit(struct not
}
}
-static struct notifier_block sem_watch_tasks_nb = {
- .notifier_call = sem_undo_task_exit
-};
-
static int used_sems;
void __init sem_init (void)
@@ -149,7 +145,6 @@ void __init sem_init (void)
" key semid perms nsems uid gid cuid cgid otime ctime\n",
&sem_ids,
sysvipc_sem_proc_show);
- register_task_watcher(&sem_watch_tasks_nb);
}
/*
@@ -958,7 +953,6 @@ static inline void unlock_semundo(void)
spin_unlock(&undo_list->lock);
}
-
/* If the task doesn't already have a undo_list, then allocate one
* here. We guarantee there is only one thread using this undo list,
* and current is THE ONE
@@ -974,13 +968,24 @@ static inline int get_undo_list(struct s
{
struct sem_undo_list *undo_list;
int size;
+ struct notifier_block *semun_nb;
+ int retval;
undo_list = current->sysvsem.undo_list;
if (!undo_list) {
+ semun_nb = NULL;
+ retval = -ENOMEM;
size = sizeof(struct sem_undo_list);
undo_list = (struct sem_undo_list *) kmalloc(size, GFP_KERNEL);
if (undo_list == NULL)
- return -ENOMEM;
+ goto err;
+ semun_nb = kzalloc(sizeof(*semun_nb), GFP_KERNEL);
+ if (semun_nb == NULL)
+ goto err;
+ semun_nb->notifier_call = sem_undo_task_exit;
+ retval = register_per_task_watcher(semun_nb);
+ if (retval)
+ goto err;
memset(undo_list, 0, size);
spin_lock_init(&undo_list->lock);
atomic_set(&undo_list->refcnt, 1);
@@ -988,6 +993,10 @@ static inline int get_undo_list(struct s
}
*undo_listp = undo_list;
return 0;
+err:
+ kfree(semun_nb);
+ kfree(undo_list);
+ return retval;
}
static struct sem_undo *lookup_undo(struct sem_undo_list *ulp, int semid)
_
Patches currently in -mm which might be from matthltc@xxxxxxxxxx are
kernel-bug-fixing-for-kernel-kmodc.patch
task-watchers-register-per-task-semundo-watcher.patch
ipc-replace-kmalloc-and-memset-in-get_undo_list-with-kzalloc.patch
-
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