From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tao Ma Date: Mon, 16 Aug 2010 15:39:15 +0800 Subject: [Ocfs2-devel] [PATCH] CMWQ: Set workqueue name before we process one work. Message-ID: <1281944355-4379-1-git-send-email-tao.ma@oracle.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-kernel@vger.kernel.org Cc: ocfs2-devel@oss.oracle.com, Tao Ma , Tejun Heo Now in CMWQ, workqueue threads are named as 'kworker/*'. So it is a little boring to see in the 'top'(below) and actually it isn't meaningful for the users. 12606 root 20 0 0 0 0 S 2 0.0 0:03.22 kworker/u:0 12607 root 20 0 0 0 0 S 1 0.0 0:03.69 kworker/u:4 So this patch just try to set the proper workqueue name if it does exist. Yes, workqueue now is a thread pool and the data may be not accurate but I think it is better(below) than the 'kworker*' stuff. And if there is something block the workqueue, we can find the caller easily. 12606 root 20 0 0 0 0 D 2 0.0 0:02.90 dlm_wq 12607 root 20 0 0 0 0 D 0 0.0 0:03.21 ocfs2_wq What's more, in ocfs2, we sometimes want to print some debug info in the system log and we use 'current->comm' to print the thread and this change also does help. The only thing I am not clear is that do we need [gs]et_task_comm? I guess not and this patch just try to use strlcpy without task_lock. Cc: Tejun Heo Signed-off-by: Tao Ma --- kernel/workqueue.c | 10 ++++++++++ 1 files changed, 10 insertions(+), 0 deletions(-) diff --git a/kernel/workqueue.c b/kernel/workqueue.c index 2994a0e..69402f8 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -1730,6 +1730,7 @@ static void process_one_work(struct worker *worker, struct work_struct *work) work_func_t f = work->func; int work_color; struct worker *collision; + char comm_saved[TASK_COMM_LEN]; #ifdef CONFIG_LOCKDEP /* * It is permissible to free the struct work_struct from @@ -1790,7 +1791,16 @@ static void process_one_work(struct worker *worker, struct work_struct *work) work_clear_pending(work); lock_map_acquire(&cwq->wq->lockdep_map); lock_map_acquire(&lockdep_map); + if (cwq->wq->name) { + strlcpy(comm_saved, worker->task->comm, + sizeof(comm_saved)); + strlcpy(worker->task->comm, cwq->wq->name, + sizeof(worker->task->comm)); + } f(work); + if (cwq->wq->name) + strlcpy(worker->task->comm, comm_saved, + sizeof(worker->task->comm)); lock_map_release(&lockdep_map); lock_map_release(&cwq->wq->lockdep_map); -- 1.7.1.GIT