From: Paul E. McKenney on
Hello!

Would you like to carry this patch, or should I push it up -tip?
If I don't hear otherwise from you, I will push it up -tip.
The INIT_RCU_HEAD() primitive is going away in favor of debugobjects.

Thanx, Paul

------------------------------------------------------------------------

fs: remove all rcu head initializations, except on_stack initializations

Remove all rcu head inits. We don't care about the RCU head state before passing
it to call_rcu() anyway. Only leave the "on_stack" variants so debugobjects can
keep track of objects on stack.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers(a)efficios.com>
Signed-off-by: Paul E. McKenney <paulmck(a)linux.vnet.ibm.com>
Cc: Alexander Viro <viro(a)zeniv.linux.org.uk>
Cc: Andries Brouwer <aeb(a)cwi.nl>

diff --git a/fs/file.c b/fs/file.c
index 34bb7f7..cccaead 100644
--- a/fs/file.c
+++ b/fs/file.c
@@ -178,7 +178,6 @@ static struct fdtable * alloc_fdtable(unsigned int nr)
fdt->open_fds = (fd_set *)data;
data += nr / BITS_PER_BYTE;
fdt->close_on_exec = (fd_set *)data;
- INIT_RCU_HEAD(&fdt->rcu);
fdt->next = NULL;

return fdt;
@@ -312,7 +311,6 @@ struct files_struct *dup_fd(struct files_struct *oldf, int *errorp)
new_fdt->close_on_exec = (fd_set *)&newf->close_on_exec_init;
new_fdt->open_fds = (fd_set *)&newf->open_fds_init;
new_fdt->fd = &newf->fd_array[0];
- INIT_RCU_HEAD(&new_fdt->rcu);
new_fdt->next = NULL;

spin_lock(&oldf->file_lock);
@@ -430,7 +428,6 @@ struct files_struct init_files = {
.fd = &init_files.fd_array[0],
.close_on_exec = (fd_set *)&init_files.close_on_exec_init,
.open_fds = (fd_set *)&init_files.open_fds_init,
- .rcu = RCU_HEAD_INIT,
},
.file_lock = __SPIN_LOCK_UNLOCKED(init_task.file_lock),
};
diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c
index 4b37f7c..ea38c65 100644
--- a/fs/fs-writeback.c
+++ b/fs/fs-writeback.c
@@ -75,12 +75,33 @@ static inline bool bdi_work_on_stack(struct bdi_work *work)
return test_bit(WS_ONSTACK_B, &work->state);
}

-static inline void bdi_work_init(struct bdi_work *work,
- struct wb_writeback_args *args)
+static inline void __bdi_work_init(struct bdi_work *work,
+ struct wb_writeback_args *args,
+ int on_stack)
{
- INIT_RCU_HEAD(&work->rcu_head);
work->args = *args;
work->state = WS_USED;
+ if (on_stack) {
+ work->state |= WS_ONSTACK;
+ init_rcu_head_on_stack(&work->rcu_head);
+ }
+}
+
+static inline void bdi_work_init(struct bdi_work *work,
+ struct wb_writeback_args *args)
+{
+ __bdi_work_init(work, args, false);
+}
+
+static inline void bdi_work_init_on_stack(struct bdi_work *work,
+ struct wb_writeback_args *args)
+{
+ __bdi_work_init(work, args, true);
+}
+
+static inline void bdi_destroy_work_on_stack(struct bdi_work *work)
+{
+ destroy_rcu_head_on_stack(&work->rcu_head);
}

/**
@@ -233,11 +254,11 @@ static void bdi_sync_writeback(struct backing_dev_info *bdi,
};
struct bdi_work work;

- bdi_work_init(&work, &args);
- work.state |= WS_ONSTACK;
+ bdi_work_init_on_stack(&work, &args);

bdi_queue_work(bdi, &work);
bdi_wait_on_work_clear(&work);
+ bdi_destroy_work_on_stack(&work);
}

/**
diff --git a/fs/partitions/check.c b/fs/partitions/check.c
index e238ab2..7444e6f 100644
--- a/fs/partitions/check.c
+++ b/fs/partitions/check.c
@@ -456,7 +456,6 @@ struct hd_struct *add_partition(struct gendisk *disk, int partno,
}

/* everything is up and running, commence */
- INIT_RCU_HEAD(&p->rcu_head);
rcu_assign_pointer(ptbl->part[partno], p);

/* suppress uevent if the disk supresses it */
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo(a)vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/