Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751183AbXB1UXg (ORCPT ); Wed, 28 Feb 2007 15:23:36 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751282AbXB1UXg (ORCPT ); Wed, 28 Feb 2007 15:23:36 -0500 Received: from ogre.sisk.pl ([217.79.144.158]:44332 "EHLO ogre.sisk.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751183AbXB1UXe (ORCPT ); Wed, 28 Feb 2007 15:23:34 -0500 From: "Rafael J. Wysocki" To: Oleg Nesterov Subject: Re: Problem with freezable workqueues Date: Wed, 28 Feb 2007 21:25:52 +0100 User-Agent: KMail/1.9.5 Cc: vatsa@in.ibm.com, Pavel Machek , Gautham R Shenoy , Johannes Berg , LKML References: <200702272251.28844.rjw@sisk.pl> <200702282043.24779.rjw@sisk.pl> <20070228200853.GA122@tv-sign.ru> In-Reply-To: <20070228200853.GA122@tv-sign.ru> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200702282125.53318.rjw@sisk.pl> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5897 Lines: 165 On Wednesday, 28 February 2007 21:08, Oleg Nesterov wrote: > On 02/28, Rafael J. Wysocki wrote: > > > > On Wednesday, 28 February 2007 20:32, Oleg Nesterov wrote: > > > > > > I am sorry, I lost track of this problem. As for 2.6.21, create_freezeable_workqueue > > > doesn't work and conflict with suspend. Why can't we remove it from XFS as you > > > suggested before? > > > > Yes, we can (preparing a patch). I was just curious. :-) > > OK, thanks. > > We can (I think) do pretty much the same with some additional complications > in worker_thread() (check !cpu_online() after try_to_freeze() and break). Okay, but I've just finished the patch that removes the freezability of workqueues (appended), so can we please do this in a separate one? Rafael --- Since freezable workqueues are broken in 2.6.21-rc (cf. http://marc.theaimsgroup.com/?l=linux-kernel&m=116855740612755, http://marc.theaimsgroup.com/?l=linux-kernel&m=117261312523921&w=2) it's better to remove them altogether for 2.6.21 and change the only user of them (XFS) accordingly. --- fs/xfs/linux-2.6/xfs_buf.c | 4 ++-- include/linux/workqueue.h | 8 +++----- kernel/workqueue.c | 21 +++++++-------------- 3 files changed, 12 insertions(+), 21 deletions(-) Index: linux-2.6.21-rc2/kernel/workqueue.c =================================================================== --- linux-2.6.21-rc2.orig/kernel/workqueue.c +++ linux-2.6.21-rc2/kernel/workqueue.c @@ -59,7 +59,6 @@ struct cpu_workqueue_struct { int run_depth; /* Detect run_workqueue() recursion depth */ - int freezeable; /* Freeze the thread during suspend */ } ____cacheline_aligned; /* @@ -352,8 +351,7 @@ static int worker_thread(void *__cwq) struct k_sigaction sa; sigset_t blocked; - if (!cwq->freezeable) - current->flags |= PF_NOFREEZE; + current->flags |= PF_NOFREEZE; set_user_nice(current, -5); @@ -376,9 +374,6 @@ static int worker_thread(void *__cwq) set_current_state(TASK_INTERRUPTIBLE); while (!kthread_should_stop()) { - if (cwq->freezeable) - try_to_freeze(); - add_wait_queue(&cwq->more_work, &wait); if (list_empty(&cwq->worklist)) schedule(); @@ -454,8 +449,8 @@ void fastcall flush_workqueue(struct wor } EXPORT_SYMBOL_GPL(flush_workqueue); -static struct task_struct *create_workqueue_thread(struct workqueue_struct *wq, - int cpu, int freezeable) +static struct task_struct +*create_workqueue_thread(struct workqueue_struct *wq, int cpu) { struct cpu_workqueue_struct *cwq = per_cpu_ptr(wq->cpu_wq, cpu); struct task_struct *p; @@ -465,7 +460,6 @@ static struct task_struct *create_workqu cwq->thread = NULL; cwq->insert_sequence = 0; cwq->remove_sequence = 0; - cwq->freezeable = freezeable; INIT_LIST_HEAD(&cwq->worklist); init_waitqueue_head(&cwq->more_work); init_waitqueue_head(&cwq->work_done); @@ -480,8 +474,7 @@ static struct task_struct *create_workqu return p; } -struct workqueue_struct *__create_workqueue(const char *name, - int singlethread, int freezeable) +struct workqueue_struct *__create_workqueue(const char *name, int singlethread) { int cpu, destroy = 0; struct workqueue_struct *wq; @@ -501,7 +494,7 @@ struct workqueue_struct *__create_workqu mutex_lock(&workqueue_mutex); if (singlethread) { INIT_LIST_HEAD(&wq->list); - p = create_workqueue_thread(wq, singlethread_cpu, freezeable); + p = create_workqueue_thread(wq, singlethread_cpu); if (!p) destroy = 1; else @@ -509,7 +502,7 @@ struct workqueue_struct *__create_workqu } else { list_add(&wq->list, &workqueues); for_each_online_cpu(cpu) { - p = create_workqueue_thread(wq, cpu, freezeable); + p = create_workqueue_thread(wq, cpu); if (p) { kthread_bind(p, cpu); wake_up_process(p); @@ -760,7 +753,7 @@ static int __devinit workqueue_cpu_callb mutex_lock(&workqueue_mutex); /* Create a new workqueue thread for it. */ list_for_each_entry(wq, &workqueues, list) { - if (!create_workqueue_thread(wq, hotcpu, 0)) { + if (!create_workqueue_thread(wq, hotcpu)) { printk("workqueue for %i failed\n", hotcpu); return NOTIFY_BAD; } Index: linux-2.6.21-rc2/include/linux/workqueue.h =================================================================== --- linux-2.6.21-rc2.orig/include/linux/workqueue.h +++ linux-2.6.21-rc2/include/linux/workqueue.h @@ -159,11 +159,9 @@ struct execute_work { extern struct workqueue_struct *__create_workqueue(const char *name, - int singlethread, - int freezeable); -#define create_workqueue(name) __create_workqueue((name), 0, 0) -#define create_freezeable_workqueue(name) __create_workqueue((name), 0, 1) -#define create_singlethread_workqueue(name) __create_workqueue((name), 1, 0) + int singlethread); +#define create_workqueue(name) __create_workqueue((name), 0) +#define create_singlethread_workqueue(name) __create_workqueue((name), 1) extern void destroy_workqueue(struct workqueue_struct *wq); Index: linux-2.6.21-rc2/fs/xfs/linux-2.6/xfs_buf.c =================================================================== --- linux-2.6.21-rc2.orig/fs/xfs/linux-2.6/xfs_buf.c +++ linux-2.6.21-rc2/fs/xfs/linux-2.6/xfs_buf.c @@ -1829,11 +1829,11 @@ xfs_buf_init(void) if (!xfs_buf_zone) goto out_free_trace_buf; - xfslogd_workqueue = create_freezeable_workqueue("xfslogd"); + xfslogd_workqueue = create_workqueue("xfslogd"); if (!xfslogd_workqueue) goto out_free_buf_zone; - xfsdatad_workqueue = create_freezeable_workqueue("xfsdatad"); + xfsdatad_workqueue = create_workqueue("xfsdatad"); if (!xfsdatad_workqueue) goto out_destroy_xfslogd_workqueue; - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/