Module Ref Counting & ibmphp

Module Ref Counting & ibmphp

[Srihari Vijayaraghavan]

Before (in 2.6.16-rc*):
$ egrep 'ibmphp' /proc/modules
ibmphp 67809 4294967295 - Live 0xf8910000
             ^^^^^^^^^^

After [1]:
ibmphp 64224 0 - Live 0xf8965000
             ^

Of course, now I'm able to successfully unload ibmphp
(& subsequently load it too :)) without any
observeable problems.

It'd seem, thro struct hotplug_slot_ops, module ref
count for ibmphp is taken care of. No?

Correct me, if I'm completely wrong here. Perhaps,
there may be a better way to address this that I'm
unaware of. If so, enlighten me.

I'm afraid I've no hardware to verify whether the
patch introduces any regressions.

Thanks

[1]
--- 2.6.16-rc6/drivers/pci/hotplug/ibmphp_core.c.orig
2006-03-15 03:37:38.000000000 +1100
+++ 2.6.16-rc6/drivers/pci/hotplug/ibmphp_core.c
2006-03-14 16:57:26.000000000 +1100
@@ -1398,10 +1398,6 @@
 		goto error;
 	}
 
-	/* lock ourselves into memory with a module 
-	 * count of -1 so that no one can unload us. */
-	module_put(THIS_MODULE);
-
 exit:
 	return rc;




		
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Re: Module Ref Counting & ibmphp

[Greg KH]

On Wed, Mar 15, 2006 at 09:47:00AM +1100, Srihari Vijayaraghavan wrote:
> Before (in 2.6.16-rc*):
> $ egrep 'ibmphp' /proc/modules
> ibmphp 67809 4294967295 - Live 0xf8910000
>              ^^^^^^^^^^
> 
> After [1]:
> ibmphp 64224 0 - Live 0xf8965000
>              ^
> 
> Of course, now I'm able to successfully unload ibmphp
> (& subsequently load it too :)) without any
> observeable problems.
> 
> It'd seem, thro struct hotplug_slot_ops, module ref
> count for ibmphp is taken care of. No?

No.  I don't think this driver likes to be unloaded due to the
instability of the hardware if that happens.  So let's just let it not
be unloaded, and hope that the hardware can die in peace and never get
put into any new machines...

thanks,

greg k-h

Re: Module Ref Counting & ibmphp

[Stephen Hemminger]

On Tue, 14 Mar 2006 16:02:12 -0800
Greg KH <greg@kroah.com> wrote:

> On Wed, Mar 15, 2006 at 09:47:00AM +1100, Srihari Vijayaraghavan wrote:
> > Before (in 2.6.16-rc*):
> > $ egrep 'ibmphp' /proc/modules
> > ibmphp 67809 4294967295 - Live 0xf8910000
> >              ^^^^^^^^^^
> > 
> > After [1]:
> > ibmphp 64224 0 - Live 0xf8965000
> >              ^
> > 
> > Of course, now I'm able to successfully unload ibmphp
> > (& subsequently load it too :)) without any
> > observeable problems.
> > 
> > It'd seem, thro struct hotplug_slot_ops, module ref
> > count for ibmphp is taken care of. No?
> 
> No.  I don't think this driver likes to be unloaded due to the
> instability of the hardware if that happens.  So let's just let it not
> be unloaded, and hope that the hardware can die in peace and never get
> put into any new machines...
> 
> thanks,
> 
> greg k-h

The proper way to prevent unloading is just not to have a module exit routine,
rather than causing ref count to be off. The the module subsystem will
mark it as unsafe to unload. Unless it wants to allow unsafe forced unload.
But IMHO either it needs to be safe to unload or not allow it.

--- linux-2.6/drivers/pci/hotplug/ibmphp_core.c.orig	2006-03-14 16:18:14.000000000 -0800
+++ linux-2.6/drivers/pci/hotplug/ibmphp_core.c	2006-03-14 16:19:12.000000000 -0800
@@ -1398,10 +1398,6 @@ static int __init ibmphp_init(void)
 		goto error;
 	}
 
-	/* lock ourselves into memory with a module 
-	 * count of -1 so that no one can unload us. */
-	module_put(THIS_MODULE);
-
 exit:
 	return rc;
 
@@ -1409,14 +1405,4 @@ error:
 	ibmphp_unload();
 	goto exit;
 }
-
-static void __exit ibmphp_exit(void)
-{
-	ibmphp_hpc_stop_poll_thread();
-	debug("after polling\n");
-	ibmphp_unload();
-	debug("done\n");
-}
-
 module_init(ibmphp_init);
-module_exit(ibmphp_exit);

Re: Module Ref Counting & ibmphp

[Daniel Barkalow]

On Tue, 14 Mar 2006, Stephen Hemminger wrote:

> The proper way to prevent unloading is just not to have a module exit routine,
> rather than causing ref count to be off. The the module subsystem will
> mark it as unsafe to unload. Unless it wants to allow unsafe forced unload.
> But IMHO either it needs to be safe to unload or not allow it.

Maybe add a comment where module_exit was, saying that the hardware can't 
be made to behave without the module, so people don't think that debugging 
the module could make it safely unloadable?

	-Daniel
*This .sig left intentionally blank*

[2.6 patch] disallow unloading of ibmphp

[Adrian Bunk]

On Tue, Mar 14, 2006 at 04:21:04PM -0800, Stephen Hemminger wrote:
> On Tue, 14 Mar 2006 16:02:12 -0800
> Greg KH <greg@kroah.com> wrote:
> 
> > On Wed, Mar 15, 2006 at 09:47:00AM +1100, Srihari Vijayaraghavan wrote:
> > > Before (in 2.6.16-rc*):
> > > $ egrep 'ibmphp' /proc/modules
> > > ibmphp 67809 4294967295 - Live 0xf8910000
> > >              ^^^^^^^^^^
> > > 
> > > After [1]:
> > > ibmphp 64224 0 - Live 0xf8965000
> > >              ^
> > > 
> > > Of course, now I'm able to successfully unload ibmphp
> > > (& subsequently load it too :)) without any
> > > observeable problems.
> > > 
> > > It'd seem, thro struct hotplug_slot_ops, module ref
> > > count for ibmphp is taken care of. No?
> > 
> > No.  I don't think this driver likes to be unloaded due to the
> > instability of the hardware if that happens.  So let's just let it not
> > be unloaded, and hope that the hardware can die in peace and never get
> > put into any new machines...
> > 
> > thanks,
> > 
> > greg k-h
> 
> The proper way to prevent unloading is just not to have a module exit routine,
> rather than causing ref count to be off. The the module subsystem will
> mark it as unsafe to unload. Unless it wants to allow unsafe forced unload.
> But IMHO either it needs to be safe to unload or not allow it.
>...


What about the patch below that also adds a comment and removes some 
more code?

I'll send a "diff -uwp" for better readability of the ibmphp_hpc.c 
changes in a reply.


<--  snip  -->


The ibmphp driver shouldn't be unloaded.

This patch replaces the module_exit() with a comment why it shouldn't 
happen and removes some now no longer needed code.


Signed-off-by: Adrian Bunk <bunk@stusta.de>

---

 drivers/pci/hotplug/ibmphp.h      |    1 
 drivers/pci/hotplug/ibmphp_core.c |   24 +---
 drivers/pci/hotplug/ibmphp_hpc.c  |  178 +++++++++++-------------------
 3 files changed, 76 insertions(+), 127 deletions(-)

--- linux-2.6.16-rc6-mm1-full/drivers/pci/hotplug/ibmphp_core.c.old	2006-03-17 20:51:09.000000000 +0100
+++ linux-2.6.16-rc6-mm1-full/drivers/pci/hotplug/ibmphp_core.c	2006-03-17 21:00:52.000000000 +0100
@@ -736,7 +736,7 @@ static struct pci_func *ibm_slot_find(u8
  * the pointers to pci_func, bus, hotplug_slot, controller,
  * and deregistering from the hotplug core
  *************************************************************/
-static void free_slots(void)
+static __init void free_slots(void)
 {
 	struct slot *slot_cur;
 	struct list_head * tmp;
@@ -1328,7 +1328,7 @@ struct hotplug_slot_ops ibmphp_hotplug_s
 */
 };
 
-static void ibmphp_unload(void)
+static void __init ibmphp_unload(void)
 {
 	free_slots();
 	debug("after slots\n");
@@ -1398,10 +1398,6 @@ static int __init ibmphp_init(void)
 		goto error;
 	}
 
-	/* lock ourselves into memory with a module 
-	 * count of -1 so that no one can unload us. */
-	module_put(THIS_MODULE);
-
 exit:
 	return rc;
 
@@ -1410,13 +1406,11 @@ error:
 	goto exit;
 }
 
-static void __exit ibmphp_exit(void)
-{
-	ibmphp_hpc_stop_poll_thread();
-	debug("after polling\n");
-	ibmphp_unload();
-	debug("done\n");
-}
-
 module_init(ibmphp_init);
-module_exit(ibmphp_exit);
+
+/* Greg KH <greg@kroah.com>:
+ * I don't think this driver likes to be unloaded due to the
+ * instability of the hardware if that happens.  So let's just let it not
+ * be unloaded, and hope that the hardware can die in peace and never get
+ * put into any new machines...
+ */
--- linux-2.6.16-rc6-mm1-full/drivers/pci/hotplug/ibmphp.h.old	2006-03-17 20:52:49.000000000 +0100
+++ linux-2.6.16-rc6-mm1-full/drivers/pci/hotplug/ibmphp.h	2006-03-17 20:52:55.000000000 +0100
@@ -398,7 +398,6 @@ extern int ibmphp_hpc_writeslot (struct 
 extern void ibmphp_lock_operations (void);
 extern void ibmphp_unlock_operations (void);
 extern int ibmphp_hpc_start_poll_thread (void);
-extern void ibmphp_hpc_stop_poll_thread (void);
 
 //----------------------------------------------------------------------------
 
--- linux-2.6.16-rc6-mm1-full/drivers/pci/hotplug/ibmphp_hpc.c.old	2006-03-17 20:53:02.000000000 +0100
+++ linux-2.6.16-rc6-mm1-full/drivers/pci/hotplug/ibmphp_hpc.c	2006-03-17 20:58:49.000000000 +0100
@@ -101,12 +101,10 @@ static int to_debug = FALSE;
 //----------------------------------------------------------------------------
 // global variables
 //----------------------------------------------------------------------------
-static int ibmphp_shutdown;
 static int tid_poll;
 static struct mutex sem_hpcaccess;	// lock access to HPC
 static struct semaphore semOperations;	// lock all operations and
 					// access to data structures
-static struct semaphore sem_exit;	// make sure polling thread goes away
 //----------------------------------------------------------------------------
 // local function prototypes
 //----------------------------------------------------------------------------
@@ -135,9 +133,7 @@ void __init ibmphp_hpc_initvars (void)
 
 	mutex_init(&sem_hpcaccess);
 	init_MUTEX (&semOperations);
-	init_MUTEX_LOCKED (&sem_exit);
 	to_debug = FALSE;
-	ibmphp_shutdown = FALSE;
 	tid_poll = 0;
 
 	debug ("%s - Exit\n", __FUNCTION__);
@@ -833,87 +829,78 @@ static void poll_hpc (void)
 
 	debug ("%s - Entry\n", __FUNCTION__);
 
-	while (!ibmphp_shutdown) {
-		if (ibmphp_shutdown) 
-			break;
-		
-		/* try to get the lock to do some kind of hardware access */
-		down (&semOperations);
+	/* try to get the lock to do some kind of hardware access */
+	down (&semOperations);
 
-		switch (poll_state) {
-		case POLL_LATCH_REGISTER: 
-			oldlatchlow = curlatchlow;
-			ctrl_count = 0x00;
-			list_for_each (pslotlist, &ibmphp_slot_head) {
-				if (ctrl_count >= ibmphp_get_total_controllers())
-					break;
-				pslot = list_entry (pslotlist, struct slot, ibm_slot_list);
-				if (pslot->ctrl->ctlr_relative_id == ctrl_count) {
-					ctrl_count++;
-					if (READ_SLOT_LATCH (pslot->ctrl)) {
-						rc = ibmphp_hpc_readslot (pslot,
-									  READ_SLOTLATCHLOWREG,
-									  &curlatchlow);
-						if (oldlatchlow != curlatchlow)
-							process_changeinlatch (oldlatchlow,
-									       curlatchlow,
-									       pslot->ctrl);
-					}
-				}
-			}
-			++poll_count;
-			poll_state = POLL_SLEEP;
-			break;
-		case POLL_SLOTS:
-			list_for_each (pslotlist, &ibmphp_slot_head) {
-				pslot = list_entry (pslotlist, struct slot, ibm_slot_list);
-				// make a copy of the old status
-				memcpy ((void *) &myslot, (void *) pslot,
-					sizeof (struct slot));
-				rc = ibmphp_hpc_readslot (pslot, READ_ALLSTAT, NULL);
-				if ((myslot.status != pslot->status)
-				    || (myslot.ext_status != pslot->ext_status))
-					process_changeinstatus (pslot, &myslot);
-			}
-			ctrl_count = 0x00;
-			list_for_each (pslotlist, &ibmphp_slot_head) {
-				if (ctrl_count >= ibmphp_get_total_controllers())
-					break;
-				pslot = list_entry (pslotlist, struct slot, ibm_slot_list);
-				if (pslot->ctrl->ctlr_relative_id == ctrl_count) {
-					ctrl_count++;
-					if (READ_SLOT_LATCH (pslot->ctrl))
-						rc = ibmphp_hpc_readslot (pslot,
-									  READ_SLOTLATCHLOWREG,
-									  &curlatchlow);
+	switch (poll_state) {
+	case POLL_LATCH_REGISTER: 
+		oldlatchlow = curlatchlow;
+		ctrl_count = 0x00;
+		list_for_each (pslotlist, &ibmphp_slot_head) {
+			if (ctrl_count >= ibmphp_get_total_controllers())
+				break;
+			pslot = list_entry (pslotlist, struct slot, ibm_slot_list);
+			if (pslot->ctrl->ctlr_relative_id == ctrl_count) {
+				ctrl_count++;
+				if (READ_SLOT_LATCH (pslot->ctrl)) {
+					rc = ibmphp_hpc_readslot (pslot,
+								  READ_SLOTLATCHLOWREG,
+								  &curlatchlow);
+					if (oldlatchlow != curlatchlow)
+						process_changeinlatch (oldlatchlow,
+								       curlatchlow,
+								       pslot->ctrl);
 				}
 			}
-			++poll_count;
-			poll_state = POLL_SLEEP;
-			break;
-		case POLL_SLEEP:
-			/* don't sleep with a lock on the hardware */
-			up (&semOperations);
-			msleep(POLL_INTERVAL_SEC * 1000);
-
-			if (ibmphp_shutdown) 
+		}
+		++poll_count;
+		poll_state = POLL_SLEEP;
+		break;
+	case POLL_SLOTS:
+		list_for_each (pslotlist, &ibmphp_slot_head) {
+			pslot = list_entry (pslotlist, struct slot, ibm_slot_list);
+			// make a copy of the old status
+			memcpy ((void *) &myslot, (void *) pslot,
+				sizeof (struct slot));
+			rc = ibmphp_hpc_readslot (pslot, READ_ALLSTAT, NULL);
+			if ((myslot.status != pslot->status)
+			    || (myslot.ext_status != pslot->ext_status))
+				process_changeinstatus (pslot, &myslot);
+		}
+		ctrl_count = 0x00;
+		list_for_each (pslotlist, &ibmphp_slot_head) {
+			if (ctrl_count >= ibmphp_get_total_controllers())
 				break;
-			
-			down (&semOperations);
-			
-			if (poll_count >= POLL_LATCH_CNT) {
-				poll_count = 0;
-				poll_state = POLL_SLOTS;
-			} else
-				poll_state = POLL_LATCH_REGISTER;
-			break;
-		}	
-		/* give up the hardware semaphore */
+			pslot = list_entry (pslotlist, struct slot, ibm_slot_list);
+			if (pslot->ctrl->ctlr_relative_id == ctrl_count) {
+				ctrl_count++;
+				if (READ_SLOT_LATCH (pslot->ctrl))
+					rc = ibmphp_hpc_readslot (pslot,
+								  READ_SLOTLATCHLOWREG,
+								  &curlatchlow);
+			}
+		}
+		++poll_count;
+		poll_state = POLL_SLEEP;
+		break;
+	case POLL_SLEEP:
+		/* don't sleep with a lock on the hardware */
 		up (&semOperations);
-		/* sleep for a short time just for good measure */
-		msleep(100);
-	}
-	up (&sem_exit);
+		msleep(POLL_INTERVAL_SEC * 1000);
+		
+		down (&semOperations);
+		
+		if (poll_count >= POLL_LATCH_CNT) {
+			poll_count = 0;
+			poll_state = POLL_SLOTS;
+		} else
+			poll_state = POLL_LATCH_REGISTER;
+		break;
+	}	
+	/* give up the hardware semaphore */
+	up (&semOperations);
+	/* sleep for a short time just for good measure */
+	msleep(100);
 	debug ("%s - Exit\n", __FUNCTION__);
 }
 
@@ -1094,37 +1081,6 @@ int __init ibmphp_hpc_start_poll_thread 
 }
 
 /*----------------------------------------------------------------------
-* Name:    ibmphp_hpc_stop_poll_thread
-*
-* Action:  stop polling thread and cleanup
-*---------------------------------------------------------------------*/
-void __exit ibmphp_hpc_stop_poll_thread (void)
-{
-	debug ("%s - Entry\n", __FUNCTION__);
-
-	ibmphp_shutdown = TRUE;
-	debug ("before locking operations \n");
-	ibmphp_lock_operations ();
-	debug ("after locking operations \n");
-	
-	// wait for poll thread to exit
-	debug ("before sem_exit down \n");
-	down (&sem_exit);
-	debug ("after sem_exit down \n");
-
-	// cleanup
-	debug ("before free_hpc_access \n");
-	free_hpc_access ();
-	debug ("after free_hpc_access \n");
-	ibmphp_unlock_operations ();
-	debug ("after unlock operations \n");
-	up (&sem_exit);
-	debug ("after sem exit up\n");
-
-	debug ("%s - Exit\n", __FUNCTION__);
-}
-
-/*----------------------------------------------------------------------
 * Name:    hpc_wait_ctlr_notworking
 *
 * Action:  wait until the controller is in a not working state

Re: [2.6 patch] disallow unloading of ibmphp

[Adrian Bunk]

On Fri, Mar 17, 2006 at 09:20:09PM +0100, Adrian Bunk wrote:
> On Tue, Mar 14, 2006 at 04:21:04PM -0800, Stephen Hemminger wrote:
> > On Tue, 14 Mar 2006 16:02:12 -0800
> > Greg KH <greg@kroah.com> wrote:
> > 
> > > On Wed, Mar 15, 2006 at 09:47:00AM +1100, Srihari Vijayaraghavan wrote:
> > > > Before (in 2.6.16-rc*):
> > > > $ egrep 'ibmphp' /proc/modules
> > > > ibmphp 67809 4294967295 - Live 0xf8910000
> > > >              ^^^^^^^^^^
> > > > 
> > > > After [1]:
> > > > ibmphp 64224 0 - Live 0xf8965000
> > > >              ^
> > > > 
> > > > Of course, now I'm able to successfully unload ibmphp
> > > > (& subsequently load it too :)) without any
> > > > observeable problems.
> > > > 
> > > > It'd seem, thro struct hotplug_slot_ops, module ref
> > > > count for ibmphp is taken care of. No?
> > > 
> > > No.  I don't think this driver likes to be unloaded due to the
> > > instability of the hardware if that happens.  So let's just let it not
> > > be unloaded, and hope that the hardware can die in peace and never get
> > > put into any new machines...
> > > 
> > > thanks,
> > > 
> > > greg k-h
> > 
> > The proper way to prevent unloading is just not to have a module exit routine,
> > rather than causing ref count to be off. The the module subsystem will
> > mark it as unsafe to unload. Unless it wants to allow unsafe forced unload.
> > But IMHO either it needs to be safe to unload or not allow it.
> >...
> 
> 
> What about the patch below that also adds a comment and removes some 
> more code?
> 
> I'll send a "diff -uwp" for better readability of the ibmphp_hpc.c 
> changes in a reply.

It's below.

cu
Adrian


--- linux-2.6.16-rc6-mm1-full/drivers/pci/hotplug/ibmphp_core.c.old	2006-03-17 20:51:09.000000000 +0100
+++ linux-2.6.16-rc6-mm1-full/drivers/pci/hotplug/ibmphp_core.c	2006-03-17 21:00:52.000000000 +0100
@@ -736,7 +736,7 @@ static struct pci_func *ibm_slot_find(u8
  * the pointers to pci_func, bus, hotplug_slot, controller,
  * and deregistering from the hotplug core
  *************************************************************/
-static void free_slots(void)
+static __init void free_slots(void)
 {
 	struct slot *slot_cur;
 	struct list_head * tmp;
@@ -1328,7 +1328,7 @@ struct hotplug_slot_ops ibmphp_hotplug_s
 */
 };
 
-static void ibmphp_unload(void)
+static void __init ibmphp_unload(void)
 {
 	free_slots();
 	debug("after slots\n");
@@ -1398,10 +1398,6 @@ static int __init ibmphp_init(void)
 		goto error;
 	}
 
-	/* lock ourselves into memory with a module 
-	 * count of -1 so that no one can unload us. */
-	module_put(THIS_MODULE);
-
 exit:
 	return rc;
 
@@ -1410,13 +1406,11 @@ error:
 	goto exit;
 }
 
-static void __exit ibmphp_exit(void)
-{
-	ibmphp_hpc_stop_poll_thread();
-	debug("after polling\n");
-	ibmphp_unload();
-	debug("done\n");
-}
-
 module_init(ibmphp_init);
-module_exit(ibmphp_exit);
+
+/* Greg KH <greg@kroah.com>:
+ * I don't think this driver likes to be unloaded due to the
+ * instability of the hardware if that happens.  So let's just let it not
+ * be unloaded, and hope that the hardware can die in peace and never get
+ * put into any new machines...
+ */
--- linux-2.6.16-rc6-mm1-full/drivers/pci/hotplug/ibmphp.h.old	2006-03-17 20:52:49.000000000 +0100
+++ linux-2.6.16-rc6-mm1-full/drivers/pci/hotplug/ibmphp.h	2006-03-17 20:52:55.000000000 +0100
@@ -398,7 +398,6 @@ extern int ibmphp_hpc_writeslot (struct 
 extern void ibmphp_lock_operations (void);
 extern void ibmphp_unlock_operations (void);
 extern int ibmphp_hpc_start_poll_thread (void);
-extern void ibmphp_hpc_stop_poll_thread (void);
 
 //----------------------------------------------------------------------------
 
--- linux-2.6.16-rc6-mm1-full/drivers/pci/hotplug/ibmphp_hpc.c.old	2006-03-17 20:53:02.000000000 +0100
+++ linux-2.6.16-rc6-mm1-full/drivers/pci/hotplug/ibmphp_hpc.c	2006-03-17 20:58:49.000000000 +0100
@@ -101,12 +101,10 @@ static int to_debug = FALSE;
 //----------------------------------------------------------------------------
 // global variables
 //----------------------------------------------------------------------------
-static int ibmphp_shutdown;
 static int tid_poll;
 static struct mutex sem_hpcaccess;	// lock access to HPC
 static struct semaphore semOperations;	// lock all operations and
 					// access to data structures
-static struct semaphore sem_exit;	// make sure polling thread goes away
 //----------------------------------------------------------------------------
 // local function prototypes
 //----------------------------------------------------------------------------
@@ -135,9 +133,7 @@ void __init ibmphp_hpc_initvars (void)
 
 	mutex_init(&sem_hpcaccess);
 	init_MUTEX (&semOperations);
-	init_MUTEX_LOCKED (&sem_exit);
 	to_debug = FALSE;
-	ibmphp_shutdown = FALSE;
 	tid_poll = 0;
 
 	debug ("%s - Exit\n", __FUNCTION__);
@@ -833,10 +829,6 @@ static void poll_hpc (void)
 
 	debug ("%s - Entry\n", __FUNCTION__);
 
-	while (!ibmphp_shutdown) {
-		if (ibmphp_shutdown) 
-			break;
-		
 		/* try to get the lock to do some kind of hardware access */
 		down (&semOperations);
 
@@ -896,9 +888,6 @@ static void poll_hpc (void)
 			up (&semOperations);
 			msleep(POLL_INTERVAL_SEC * 1000);
 
-			if (ibmphp_shutdown) 
-				break;
-			
 			down (&semOperations);
 			
 			if (poll_count >= POLL_LATCH_CNT) {
@@ -912,8 +901,6 @@ static void poll_hpc (void)
 		up (&semOperations);
 		/* sleep for a short time just for good measure */
 		msleep(100);
-	}
-	up (&sem_exit);
 	debug ("%s - Exit\n", __FUNCTION__);
 }
 
@@ -1094,37 +1081,6 @@ int __init ibmphp_hpc_start_poll_thread 
 }
 
 /*----------------------------------------------------------------------
-* Name:    ibmphp_hpc_stop_poll_thread
-*
-* Action:  stop polling thread and cleanup
-*---------------------------------------------------------------------*/
-void __exit ibmphp_hpc_stop_poll_thread (void)
-{
-	debug ("%s - Entry\n", __FUNCTION__);
-
-	ibmphp_shutdown = TRUE;
-	debug ("before locking operations \n");
-	ibmphp_lock_operations ();
-	debug ("after locking operations \n");
-	
-	// wait for poll thread to exit
-	debug ("before sem_exit down \n");
-	down (&sem_exit);
-	debug ("after sem_exit down \n");
-
-	// cleanup
-	debug ("before free_hpc_access \n");
-	free_hpc_access ();
-	debug ("after free_hpc_access \n");
-	ibmphp_unlock_operations ();
-	debug ("after unlock operations \n");
-	up (&sem_exit);
-	debug ("after sem exit up\n");
-
-	debug ("%s - Exit\n", __FUNCTION__);
-}
-
-/*----------------------------------------------------------------------
 * Name:    hpc_wait_ctlr_notworking
 *
 * Action:  wait until the controller is in a not working state

Re: Module Ref Counting & ibmphp

[Srihari Vijayaraghavan]

--- Greg KH <greg@kroah.com> wrote:
> [...] 
> No.  I don't think this driver likes to be unloaded
> due to the
> instability of the hardware if that happens.  So
> let's just let it not
> be unloaded, and hope that the hardware can die in
> peace and never get
> put into any new machines...

Fair enough & thanks for the explanation.

I've quickly tested Stephen's patch, which does the
trick (no more 4.3 billion usages :)).

Note to Stephen: Pls don't remove people in the cc
list. I almost missed your patch & hence my testing of
it.

Thanks



		
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Re: Module Ref Counting & ibmphp

[Randy.Dunlap]

On Wed, 15 Mar 2006 14:25:49 +1100 (EST) Srihari Vijayaraghavan wrote:

> --- Greg KH <greg@kroah.com> wrote:
> > [...] 
> > No.  I don't think this driver likes to be unloaded
> > due to the
> > instability of the hardware if that happens.  So
> > let's just let it not
> > be unloaded, and hope that the hardware can die in
> > peace and never get
> > put into any new machines...
> 
> Fair enough & thanks for the explanation.
> 
> I've quickly tested Stephen's patch, which does the
> trick (no more 4.3 billion usages :)).

That was ~0 (0xffffffff, -1) for those who missed it.

> Note to Stephen: Pls don't remove people in the cc
> list. I almost missed your patch & hence my testing of
> it.


---
~Randy