2005-09-11 20:15:07 -06:00
|
|
|
/*
|
|
|
|
* connector.c
|
connector: create connector workqueue only while needed once
The netlink connector uses its own workqueue to relay the datas sent
from userspace to the appropriate callback. If you launch the test
from Documentation/connector and change it a bit to send a high flow
of data, you will see thousands of events coming to the "cqueue"
workqueue by looking at the workqueue tracer.
This flow of events can be sent very quickly. So, to not encumber the
kevent workqueue and delay other jobs, the "cqueue" workqueue should
remain.
But this workqueue is pointless most of the time, it will always be
created (assuming you have built it of course) although only
developpers with specific needs will use it.
So avoid this "most of the time useless task", this patch proposes to
create this workqueue only when needed once. The first jobs to be
sent to connector callbacks will be sent to kevent while the "cqueue"
thread creation will be scheduled to kevent too.
The following jobs will continue to be scheduled to keventd until the
cqueue workqueue is created, and then the rest of the jobs will
continue to perform as usual, through this dedicated workqueue.
Each time I tested this patch, only the first event was sent to
keventd, the rest has been sent to cqueue which have been created
quickly.
Also, this patch fixes some trailing whitespaces on the connector files.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-02-03 00:22:04 -07:00
|
|
|
*
|
2009-07-21 13:43:51 -06:00
|
|
|
* 2004+ Copyright (c) Evgeniy Polyakov <zbr@ioremap.net>
|
2005-09-11 20:15:07 -06:00
|
|
|
* All rights reserved.
|
connector: create connector workqueue only while needed once
The netlink connector uses its own workqueue to relay the datas sent
from userspace to the appropriate callback. If you launch the test
from Documentation/connector and change it a bit to send a high flow
of data, you will see thousands of events coming to the "cqueue"
workqueue by looking at the workqueue tracer.
This flow of events can be sent very quickly. So, to not encumber the
kevent workqueue and delay other jobs, the "cqueue" workqueue should
remain.
But this workqueue is pointless most of the time, it will always be
created (assuming you have built it of course) although only
developpers with specific needs will use it.
So avoid this "most of the time useless task", this patch proposes to
create this workqueue only when needed once. The first jobs to be
sent to connector callbacks will be sent to kevent while the "cqueue"
thread creation will be scheduled to kevent too.
The following jobs will continue to be scheduled to keventd until the
cqueue workqueue is created, and then the rest of the jobs will
continue to perform as usual, through this dedicated workqueue.
Each time I tested this patch, only the first event was sent to
keventd, the rest has been sent to cqueue which have been created
quickly.
Also, this patch fixes some trailing whitespaces on the connector files.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-02-03 00:22:04 -07:00
|
|
|
*
|
2005-09-11 20:15:07 -06:00
|
|
|
* This program is free software; you can redistribute it and/or modify
|
|
|
|
* it under the terms of the GNU General Public License as published by
|
|
|
|
* the Free Software Foundation; either version 2 of the License, or
|
|
|
|
* (at your option) any later version.
|
|
|
|
*
|
|
|
|
* This program is distributed in the hope that it will be useful,
|
|
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
|
|
* GNU General Public License for more details.
|
|
|
|
*
|
|
|
|
* You should have received a copy of the GNU General Public License
|
|
|
|
* along with this program; if not, write to the Free Software
|
|
|
|
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
|
|
|
|
*/
|
|
|
|
|
|
|
|
#include <linux/kernel.h>
|
|
|
|
#include <linux/module.h>
|
|
|
|
#include <linux/list.h>
|
|
|
|
#include <linux/skbuff.h>
|
|
|
|
#include <linux/netlink.h>
|
|
|
|
#include <linux/moduleparam.h>
|
|
|
|
#include <linux/connector.h>
|
include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.
percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.
http://userweb.kernel.org/~tj/misc/slabh-sweep.py
The script does the followings.
* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.
* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.
* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.
The conversion was done in the following steps.
1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.
2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.
3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.
4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.
5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.
6. percpu.h was updated not to include slab.h.
7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).
* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig
8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.
Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.
Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-24 02:04:11 -06:00
|
|
|
#include <linux/slab.h>
|
2006-03-23 04:00:21 -07:00
|
|
|
#include <linux/mutex.h>
|
2008-06-27 21:03:24 -06:00
|
|
|
#include <linux/proc_fs.h>
|
|
|
|
#include <linux/spinlock.h>
|
2005-09-11 20:15:07 -06:00
|
|
|
|
|
|
|
#include <net/sock.h>
|
|
|
|
|
|
|
|
MODULE_LICENSE("GPL");
|
2009-07-21 13:43:51 -06:00
|
|
|
MODULE_AUTHOR("Evgeniy Polyakov <zbr@ioremap.net>");
|
2005-09-11 20:15:07 -06:00
|
|
|
MODULE_DESCRIPTION("Generic userspace <-> kernelspace connector.");
|
2010-12-10 13:27:49 -07:00
|
|
|
MODULE_ALIAS_NET_PF_PROTO(PF_NETLINK, NETLINK_CONNECTOR);
|
2005-09-11 20:15:07 -06:00
|
|
|
|
|
|
|
static struct cn_dev cdev;
|
|
|
|
|
2008-02-26 19:25:53 -07:00
|
|
|
static int cn_already_initialized;
|
2005-09-11 20:15:07 -06:00
|
|
|
|
|
|
|
/*
|
|
|
|
* msg->seq and msg->ack are used to determine message genealogy.
|
|
|
|
* When someone sends message it puts there locally unique sequence
|
|
|
|
* and random acknowledge numbers. Sequence number may be copied into
|
|
|
|
* nlmsghdr->nlmsg_seq too.
|
|
|
|
*
|
|
|
|
* Sequence number is incremented with each message to be sent.
|
|
|
|
*
|
|
|
|
* If we expect reply to our message then the sequence number in
|
|
|
|
* received message MUST be the same as in original message, and
|
|
|
|
* acknowledge number MUST be the same + 1.
|
|
|
|
*
|
|
|
|
* If we receive a message and its sequence number is not equal to the
|
|
|
|
* one we are expecting then it is a new message.
|
|
|
|
*
|
|
|
|
* If we receive a message and its sequence number is the same as one
|
|
|
|
* we are expecting but it's acknowledgement number is not equal to
|
|
|
|
* the acknowledgement number in the original message + 1, then it is
|
|
|
|
* a new message.
|
|
|
|
*
|
|
|
|
*/
|
2005-10-07 00:46:04 -06:00
|
|
|
int cn_netlink_send(struct cn_msg *msg, u32 __group, gfp_t gfp_mask)
|
2005-09-11 20:15:07 -06:00
|
|
|
{
|
|
|
|
struct cn_callback_entry *__cbq;
|
|
|
|
unsigned int size;
|
|
|
|
struct sk_buff *skb;
|
|
|
|
struct nlmsghdr *nlh;
|
|
|
|
struct cn_msg *data;
|
|
|
|
struct cn_dev *dev = &cdev;
|
|
|
|
u32 group = 0;
|
|
|
|
int found = 0;
|
|
|
|
|
|
|
|
if (!__group) {
|
|
|
|
spin_lock_bh(&dev->cbdev->queue_lock);
|
|
|
|
list_for_each_entry(__cbq, &dev->cbdev->queue_list,
|
|
|
|
callback_entry) {
|
2005-09-26 16:06:50 -06:00
|
|
|
if (cn_cb_equal(&__cbq->id.id, &msg->id)) {
|
2005-09-11 20:15:07 -06:00
|
|
|
found = 1;
|
|
|
|
group = __cbq->group;
|
2008-01-04 02:54:38 -07:00
|
|
|
break;
|
2005-09-11 20:15:07 -06:00
|
|
|
}
|
|
|
|
}
|
|
|
|
spin_unlock_bh(&dev->cbdev->queue_lock);
|
|
|
|
|
|
|
|
if (!found)
|
|
|
|
return -ENODEV;
|
|
|
|
} else {
|
|
|
|
group = __group;
|
|
|
|
}
|
|
|
|
|
2006-03-20 23:21:40 -07:00
|
|
|
if (!netlink_has_listeners(dev->nls, group))
|
|
|
|
return -ESRCH;
|
|
|
|
|
2005-09-11 20:15:07 -06:00
|
|
|
size = NLMSG_SPACE(sizeof(*msg) + msg->len);
|
|
|
|
|
|
|
|
skb = alloc_skb(size, gfp_mask);
|
|
|
|
if (!skb)
|
|
|
|
return -ENOMEM;
|
|
|
|
|
|
|
|
nlh = NLMSG_PUT(skb, 0, msg->seq, NLMSG_DONE, size - sizeof(*nlh));
|
|
|
|
|
|
|
|
data = NLMSG_DATA(nlh);
|
|
|
|
|
|
|
|
memcpy(data, msg, sizeof(*data) + msg->len);
|
|
|
|
|
|
|
|
NETLINK_CB(skb).dst_group = group;
|
|
|
|
|
2006-03-20 23:21:40 -07:00
|
|
|
return netlink_broadcast(dev->nls, skb, 0, group, gfp_mask);
|
2005-09-11 20:15:07 -06:00
|
|
|
|
|
|
|
nlmsg_failure:
|
|
|
|
kfree_skb(skb);
|
|
|
|
return -EINVAL;
|
|
|
|
}
|
2006-06-23 03:05:46 -06:00
|
|
|
EXPORT_SYMBOL_GPL(cn_netlink_send);
|
2005-09-11 20:15:07 -06:00
|
|
|
|
|
|
|
/*
|
|
|
|
* Callback helper - queues work and setup destructor for given data.
|
|
|
|
*/
|
2009-10-01 20:40:07 -06:00
|
|
|
static int cn_call_callback(struct sk_buff *skb)
|
2005-09-11 20:15:07 -06:00
|
|
|
{
|
2011-03-28 02:39:36 -06:00
|
|
|
struct cn_callback_entry *i, *cbq = NULL;
|
2005-09-11 20:15:07 -06:00
|
|
|
struct cn_dev *dev = &cdev;
|
2009-10-01 20:40:04 -06:00
|
|
|
struct cn_msg *msg = NLMSG_DATA(nlmsg_hdr(skb));
|
2011-03-28 02:39:36 -06:00
|
|
|
struct netlink_skb_parms *nsp = &NETLINK_CB(skb);
|
2005-09-26 16:06:50 -06:00
|
|
|
int err = -ENODEV;
|
2005-09-11 20:15:07 -06:00
|
|
|
|
|
|
|
spin_lock_bh(&dev->cbdev->queue_lock);
|
2011-03-28 02:39:36 -06:00
|
|
|
list_for_each_entry(i, &dev->cbdev->queue_list, callback_entry) {
|
|
|
|
if (cn_cb_equal(&i->id.id, &msg->id)) {
|
|
|
|
atomic_inc(&i->refcnt);
|
|
|
|
cbq = i;
|
2005-09-11 20:15:07 -06:00
|
|
|
break;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
spin_unlock_bh(&dev->cbdev->queue_lock);
|
|
|
|
|
2011-03-28 02:39:36 -06:00
|
|
|
if (cbq != NULL) {
|
|
|
|
cbq->callback(msg, nsp);
|
|
|
|
kfree_skb(skb);
|
|
|
|
cn_queue_release_callback(cbq);
|
2011-04-11 23:39:51 -06:00
|
|
|
err = 0;
|
2011-03-28 02:39:36 -06:00
|
|
|
}
|
|
|
|
|
2005-09-26 16:06:50 -06:00
|
|
|
return err;
|
2005-09-11 20:15:07 -06:00
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Main netlink receiving function.
|
|
|
|
*
|
2008-01-04 02:55:01 -07:00
|
|
|
* It checks skb, netlink header and msg sizes, and calls callback helper.
|
2005-09-11 20:15:07 -06:00
|
|
|
*/
|
|
|
|
static void cn_rx_skb(struct sk_buff *__skb)
|
|
|
|
{
|
|
|
|
struct nlmsghdr *nlh;
|
|
|
|
int err;
|
|
|
|
struct sk_buff *skb;
|
|
|
|
|
|
|
|
skb = skb_get(__skb);
|
|
|
|
|
|
|
|
if (skb->len >= NLMSG_SPACE(0)) {
|
2007-04-25 20:08:35 -06:00
|
|
|
nlh = nlmsg_hdr(skb);
|
2005-09-11 20:15:07 -06:00
|
|
|
|
|
|
|
if (nlh->nlmsg_len < sizeof(struct cn_msg) ||
|
|
|
|
skb->len < nlh->nlmsg_len ||
|
|
|
|
nlh->nlmsg_len > CONNECTOR_MAX_MSG_SIZE) {
|
|
|
|
kfree_skb(skb);
|
2007-10-30 21:41:49 -06:00
|
|
|
return;
|
2005-09-11 20:15:07 -06:00
|
|
|
}
|
|
|
|
|
2009-10-01 20:40:07 -06:00
|
|
|
err = cn_call_callback(skb);
|
2005-09-11 20:15:07 -06:00
|
|
|
if (err < 0)
|
|
|
|
kfree_skb(skb);
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Callback add routing - adds callback with given ID and name.
|
|
|
|
* If there is registered callback with the same ID it will not be added.
|
|
|
|
*
|
|
|
|
* May sleep.
|
|
|
|
*/
|
2011-02-19 16:45:29 -07:00
|
|
|
int cn_add_callback(struct cb_id *id, const char *name,
|
2009-10-01 20:40:05 -06:00
|
|
|
void (*callback)(struct cn_msg *, struct netlink_skb_parms *))
|
2005-09-11 20:15:07 -06:00
|
|
|
{
|
|
|
|
int err;
|
|
|
|
struct cn_dev *dev = &cdev;
|
|
|
|
|
2006-06-20 00:42:53 -06:00
|
|
|
if (!cn_already_initialized)
|
|
|
|
return -EAGAIN;
|
|
|
|
|
2005-09-26 16:06:50 -06:00
|
|
|
err = cn_queue_add_callback(dev->cbdev, name, id, callback);
|
|
|
|
if (err)
|
2005-09-11 20:15:07 -06:00
|
|
|
return err;
|
|
|
|
|
|
|
|
return 0;
|
|
|
|
}
|
2006-06-23 03:05:46 -06:00
|
|
|
EXPORT_SYMBOL_GPL(cn_add_callback);
|
2005-09-11 20:15:07 -06:00
|
|
|
|
|
|
|
/*
|
|
|
|
* Callback remove routing - removes callback
|
|
|
|
* with given ID.
|
|
|
|
* If there is no registered callback with given
|
|
|
|
* ID nothing happens.
|
|
|
|
*
|
|
|
|
* May sleep while waiting for reference counter to become zero.
|
|
|
|
*/
|
|
|
|
void cn_del_callback(struct cb_id *id)
|
|
|
|
{
|
|
|
|
struct cn_dev *dev = &cdev;
|
|
|
|
|
|
|
|
cn_queue_del_callback(dev->cbdev, id);
|
|
|
|
}
|
2006-06-23 03:05:46 -06:00
|
|
|
EXPORT_SYMBOL_GPL(cn_del_callback);
|
2005-09-11 20:15:07 -06:00
|
|
|
|
2008-06-27 21:03:24 -06:00
|
|
|
static int cn_proc_show(struct seq_file *m, void *v)
|
|
|
|
{
|
|
|
|
struct cn_queue_dev *dev = cdev.cbdev;
|
|
|
|
struct cn_callback_entry *cbq;
|
|
|
|
|
|
|
|
seq_printf(m, "Name ID\n");
|
|
|
|
|
|
|
|
spin_lock_bh(&dev->queue_lock);
|
|
|
|
|
|
|
|
list_for_each_entry(cbq, &dev->queue_list, callback_entry) {
|
|
|
|
seq_printf(m, "%-15s %u:%u\n",
|
|
|
|
cbq->id.name,
|
|
|
|
cbq->id.id.idx,
|
|
|
|
cbq->id.id.val);
|
|
|
|
}
|
|
|
|
|
|
|
|
spin_unlock_bh(&dev->queue_lock);
|
|
|
|
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
|
|
|
static int cn_proc_open(struct inode *inode, struct file *file)
|
|
|
|
{
|
|
|
|
return single_open(file, cn_proc_show, NULL);
|
|
|
|
}
|
|
|
|
|
|
|
|
static const struct file_operations cn_file_ops = {
|
|
|
|
.owner = THIS_MODULE,
|
|
|
|
.open = cn_proc_open,
|
|
|
|
.read = seq_read,
|
|
|
|
.llseek = seq_lseek,
|
|
|
|
.release = single_release
|
|
|
|
};
|
|
|
|
|
2006-06-20 00:42:53 -06:00
|
|
|
static int __devinit cn_init(void)
|
2005-09-11 20:15:07 -06:00
|
|
|
{
|
|
|
|
struct cn_dev *dev = &cdev;
|
|
|
|
|
2007-10-10 22:15:29 -06:00
|
|
|
dev->input = cn_rx_skb;
|
2005-09-11 20:15:07 -06:00
|
|
|
|
2007-09-12 05:05:38 -06:00
|
|
|
dev->nls = netlink_kernel_create(&init_net, NETLINK_CONNECTOR,
|
2005-09-11 20:15:07 -06:00
|
|
|
CN_NETLINK_USERS + 0xf,
|
2007-04-20 15:14:21 -06:00
|
|
|
dev->input, NULL, THIS_MODULE);
|
2005-09-11 20:15:07 -06:00
|
|
|
if (!dev->nls)
|
|
|
|
return -EIO;
|
|
|
|
|
|
|
|
dev->cbdev = cn_queue_alloc_dev("cqueue", dev->nls);
|
|
|
|
if (!dev->cbdev) {
|
2008-01-28 15:41:19 -07:00
|
|
|
netlink_kernel_release(dev->nls);
|
2005-09-11 20:15:07 -06:00
|
|
|
return -EINVAL;
|
|
|
|
}
|
connector: create connector workqueue only while needed once
The netlink connector uses its own workqueue to relay the datas sent
from userspace to the appropriate callback. If you launch the test
from Documentation/connector and change it a bit to send a high flow
of data, you will see thousands of events coming to the "cqueue"
workqueue by looking at the workqueue tracer.
This flow of events can be sent very quickly. So, to not encumber the
kevent workqueue and delay other jobs, the "cqueue" workqueue should
remain.
But this workqueue is pointless most of the time, it will always be
created (assuming you have built it of course) although only
developpers with specific needs will use it.
So avoid this "most of the time useless task", this patch proposes to
create this workqueue only when needed once. The first jobs to be
sent to connector callbacks will be sent to kevent while the "cqueue"
thread creation will be scheduled to kevent too.
The following jobs will continue to be scheduled to keventd until the
cqueue workqueue is created, and then the rest of the jobs will
continue to perform as usual, through this dedicated workqueue.
Each time I tested this patch, only the first event was sent to
keventd, the rest has been sent to cqueue which have been created
quickly.
Also, this patch fixes some trailing whitespaces on the connector files.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-02-03 00:22:04 -07:00
|
|
|
|
2006-06-20 00:42:53 -06:00
|
|
|
cn_already_initialized = 1;
|
2005-09-11 20:15:07 -06:00
|
|
|
|
2008-06-27 21:03:24 -06:00
|
|
|
proc_net_fops_create(&init_net, "connector", S_IRUGO, &cn_file_ops);
|
|
|
|
|
2005-09-11 20:15:07 -06:00
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
2006-06-20 00:42:53 -06:00
|
|
|
static void __devexit cn_fini(void)
|
2005-09-11 20:15:07 -06:00
|
|
|
{
|
|
|
|
struct cn_dev *dev = &cdev;
|
|
|
|
|
|
|
|
cn_already_initialized = 0;
|
|
|
|
|
2008-06-27 21:03:24 -06:00
|
|
|
proc_net_remove(&init_net, "connector");
|
|
|
|
|
2005-09-11 20:15:07 -06:00
|
|
|
cn_queue_free_dev(dev->cbdev);
|
2008-01-28 15:41:19 -07:00
|
|
|
netlink_kernel_release(dev->nls);
|
2005-09-11 20:15:07 -06:00
|
|
|
}
|
|
|
|
|
2006-06-20 00:42:53 -06:00
|
|
|
subsys_initcall(cn_init);
|
2005-09-11 20:15:07 -06:00
|
|
|
module_exit(cn_fini);
|