From: Tejun Heo <tj@kernel.org>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-kernel@vger.kernel.org, laijs@cn.fujitsu.com,
axboe@kernel.dk, jmoyer@redhat.com, zab@redhat.com,
Kay Sievers <kay.sievers@vrfy.org>
Subject: Re: [PATCH 30/31] driver/base: implement subsys_virtual_register()
Date: Sat, 2 Mar 2013 12:26:15 -0800 [thread overview]
Message-ID: <20130302202615.GA3678@htj.dyndns.org> (raw)
In-Reply-To: <20130302181727.GB2051@kroah.com>
Hello, Greg.
On Sat, Mar 02, 2013 at 10:17:27AM -0800, Greg Kroah-Hartman wrote:
> I'm almost afraid to ask what you want to export to userspace for a
> workqueue that userspace would care about...
Workqueue is being extended to support worker pools with custom
attributes so that it can replace private worker pool implementations
in writeback, btrfs and other places. They want to expose
per-workqueue tunables to userland - nice level, cpu affinity and
cgroup association of those IO threads to userland, so that's where
the sysfs interface comes in. The export is opt-in and those
workqueues should have well defined name.
> If you create a subsystem, the devices will show up under the virtual
> "bus" if you don't give them a parent, so this patch shouldn't be
> needed, unless you are abusing the driver model. What am I missing
> here?
If you don't give the parent, it ends up in /sys/devices/ with
symlinks appearing under /sys/bus/. I didn't know where to put it.
Right under /sys/devices/ doesn't seem right to me. We already have
one like that /sys/devices/software/ which actually is for perf
software events and it just is weird. I was wondering where to put it
and Kay told me that /sys/devices/virtual/ would be the best fit
although we don't yet have proper interface for it, so the patch. I
don't really care where it shows up and it apparently shouldn't matter
for userland as long as /sys/bus/ part is there but /sys/virtual/
seems to be the best fit at the moment.
Thanks.
--
tejun
next prev parent reply other threads:[~2013-03-02 20:26 UTC|newest]
Thread overview: 77+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-03-02 3:23 [PATCHSET wq/for-3.10-tmp] workqueue: implement workqueue with custom worker attributes Tejun Heo
2013-03-02 3:23 ` [PATCH 01/31] workqueue: make sanity checks less punshing using WARN_ON[_ONCE]()s Tejun Heo
2013-03-02 3:23 ` [PATCH 02/31] workqueue: make workqueue_lock irq-safe Tejun Heo
2013-03-02 3:23 ` [PATCH 03/31] workqueue: introduce kmem_cache for pool_workqueues Tejun Heo
2013-03-02 3:23 ` [PATCH 04/31] workqueue: add workqueue_struct->pwqs list Tejun Heo
2013-03-02 3:23 ` [PATCH 05/31] workqueue: replace for_each_pwq_cpu() with for_each_pwq() Tejun Heo
2013-03-02 3:23 ` [PATCH 06/31] workqueue: introduce for_each_pool() Tejun Heo
2013-03-02 3:23 ` [PATCH 07/31] workqueue: restructure pool / pool_workqueue iterations in freeze/thaw functions Tejun Heo
2013-03-10 10:09 ` Lai Jiangshan
2013-03-10 12:34 ` Tejun Heo
2013-03-02 3:23 ` [PATCH 08/31] workqueue: add wokrqueue_struct->maydays list to replace mayday cpu iterators Tejun Heo
2013-03-02 3:24 ` [PATCH 09/31] workqueue: consistently use int for @cpu variables Tejun Heo
2013-03-02 3:24 ` [PATCH 10/31] workqueue: remove workqueue_struct->pool_wq.single Tejun Heo
2013-03-02 3:24 ` [PATCH 11/31] workqueue: replace get_pwq() with explicit per_cpu_ptr() accesses and first_pwq() Tejun Heo
2013-03-02 3:24 ` [PATCH 12/31] workqueue: update synchronization rules on workqueue->pwqs Tejun Heo
2013-03-10 10:09 ` Lai Jiangshan
2013-03-10 12:38 ` Tejun Heo
2013-03-12 18:20 ` [PATCH v2 " Tejun Heo
2013-03-02 3:24 ` [PATCH 13/31] workqueue: update synchronization rules on worker_pool_idr Tejun Heo
2013-03-12 18:20 ` [PATCH v2 " Tejun Heo
2013-03-02 3:24 ` [PATCH 14/31] workqueue: replace POOL_MANAGING_WORKERS flag with worker_pool->manager_mutex Tejun Heo
2013-03-10 10:09 ` Lai Jiangshan
2013-03-10 12:46 ` Tejun Heo
2013-03-12 18:19 ` [PATCH v2 " Tejun Heo
2013-03-02 3:24 ` [PATCH 15/31] workqueue: separate out init_worker_pool() from init_workqueues() Tejun Heo
2013-03-02 3:24 ` [PATCH 16/31] workqueue: introduce workqueue_attrs Tejun Heo
2013-03-04 18:37 ` [PATCH v2 " Tejun Heo
2013-03-05 22:29 ` Ryan Mallon
2013-03-05 22:33 ` Tejun Heo
2013-03-05 22:34 ` Tejun Heo
2013-03-05 22:40 ` Ryan Mallon
2013-03-05 22:44 ` Tejun Heo
2013-03-05 23:20 ` Ryan Mallon
2013-03-05 23:28 ` Tejun Heo
2013-03-02 3:24 ` [PATCH 17/31] workqueue: implement attribute-based unbound worker_pool management Tejun Heo
2013-03-10 10:08 ` Lai Jiangshan
2013-03-10 12:58 ` Tejun Heo
2013-03-10 18:36 ` Tejun Heo
2013-03-12 18:21 ` [PATCH v2 " Tejun Heo
2013-03-02 3:24 ` [PATCH 18/31] workqueue: remove unbound_std_worker_pools[] and related helpers Tejun Heo
2013-03-02 3:24 ` [PATCH 19/31] workqueue: drop "std" from cpu_std_worker_pools and for_each_std_worker_pool() Tejun Heo
2013-03-02 3:24 ` [PATCH 20/31] workqueue: add pool ID to the names of unbound kworkers Tejun Heo
2013-03-02 3:24 ` [PATCH 21/31] workqueue: drop WQ_RESCUER and test workqueue->rescuer for NULL instead Tejun Heo
2013-03-02 3:24 ` [PATCH 22/31] workqueue: restructure __alloc_workqueue_key() Tejun Heo
2013-03-02 3:24 ` [PATCH 23/31] workqueue: implement get/put_pwq() Tejun Heo
2013-03-02 3:24 ` [PATCH 24/31] workqueue: prepare flush_workqueue() for dynamic creation and destrucion of unbound pool_workqueues Tejun Heo
2013-03-02 3:24 ` [PATCH 25/31] workqueue: perform non-reentrancy test when queueing to unbound workqueues too Tejun Heo
2013-03-02 3:24 ` [PATCH 26/31] workqueue: implement apply_workqueue_attrs() Tejun Heo
2013-03-02 3:24 ` [PATCH 27/31] workqueue: make it clear that WQ_DRAINING is an internal flag Tejun Heo
2013-03-02 3:24 ` [PATCH 28/31] workqueue: reject increasing max_active for ordered workqueues Tejun Heo
2013-03-04 18:30 ` [PATCH UPDATED 28/31] workqueue: reject adjusting max_active or applying attrs to " Tejun Heo
2013-03-02 3:24 ` [PATCH 29/31] cpumask: implement cpumask_parse() Tejun Heo
2013-03-02 3:24 ` [PATCH 30/31] driver/base: implement subsys_virtual_register() Tejun Heo
2013-03-02 18:17 ` Greg Kroah-Hartman
2013-03-02 20:26 ` Tejun Heo [this message]
2013-03-03 6:42 ` Kay Sievers
2013-03-05 20:43 ` Tejun Heo
2013-03-07 23:31 ` Greg Kroah-Hartman
2013-03-08 0:04 ` Kay Sievers
2013-03-10 11:57 ` Tejun Heo
2013-03-10 16:45 ` Greg Kroah-Hartman
2013-03-10 17:00 ` Kay Sievers
2013-03-10 17:24 ` Greg Kroah-Hartman
2013-03-10 17:50 ` Kay Sievers
2013-03-10 18:34 ` Tejun Heo
2013-03-12 18:40 ` Tejun Heo
2013-03-02 3:24 ` [PATCH 31/31] workqueue: implement sysfs interface for workqueues Tejun Heo
2013-03-04 18:30 ` [PATCH v2 " Tejun Heo
2013-03-05 20:41 ` [PATCHSET wq/for-3.10-tmp] workqueue: implement workqueue with custom worker attributes Tejun Heo
2013-03-10 10:34 ` Lai Jiangshan
2013-03-10 12:01 ` Tejun Heo
2013-03-11 15:24 ` Tejun Heo
2013-03-11 15:40 ` Lai Jiangshan
2013-03-11 15:42 ` Lai Jiangshan
2013-03-11 15:43 ` Tejun Heo
2013-03-12 18:10 ` Tejun Heo
2013-03-12 18:34 ` Tejun Heo
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