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Let IB core distribute cache update events

PATCH In review Leon Romanovsky 3 participants 9 messages Oct 20, 2019 – Oct 24, 2019 InfiniBand

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#0 lore raw

cover Let IB core distribute cache update events

From: Leon Romanovsky <[email protected]>

From Parav,

Currently when low level driver notifies Pkey, GID, port change events, they are notified to the registered handlers in the order they are registered.

IB core and other ULPs such as IPoIB are interested in GID, LID, Pkey change events. Since all GID query done by ULPs is serviced by IB core, IB core is yet to update the GID cache when IPoIB queries the GID, resulting into not updating IPoIB address. Detailed flow is shown in the patch-1.

Hence, all events which require cache update are handled first by the IB core. Once cache update work is completed, IB core distributes the event to subscriber clients.

This is tested with opensm's /etc/rdma/opensm.conf subnet_prefix configuration update where before the update

$ ip link show dev ib0
ib0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 2044 qdisc pfifo_fast
state UP mode DEFAULT group default qlen 256
    link/infiniband
80:00:01:07:fe:80:00:00:00:00:00:00:24:8a:07:03:00:b3:d1:12 brd
00:ff:ff:ff:ff:12:40:1b:ff:ff:00:00:00:00:00:00:ff:ff:ff:ff

And after the subnet prefix update:

ib0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 2044 qdisc pfifo_fast state UP mode DEFAULT group default qlen 256
link/infiniband
80:00:01:07:fe:80:00:00:00:00:00:02:24:8a:07:03:00:b3:d1:12 brd 00:ff:ff:ff:ff:12:40:1b:ff:ff:00:00:00:00:00:00:ff:ff:ff:ff

Patch-1 fixes the race condition between GID users and GID cache update Patch-2 eliminates single entry structure
Patch-3 simplifies the code to not generate the event for unregistered device

Parav Pandit (3):
IB/core: Let IB core distribute cache update events IB/core: Cut down single member ib_cache structure IB/core: Do not notify GID change event of an unregistered device

 drivers/infiniband/core/cache.c     | 132 ++++++++++++++--------------
 drivers/infiniband/core/core_priv.h |   3 +
 drivers/infiniband/core/device.c    |  26 ++++--
 include/rdma/ib_verbs.h             |   8 +-
 4 files changed, 87 insertions(+), 82 deletions(-)

--
2.20.1

#1 lore raw

PATCH 1/3 IB/core: Let IB core distribute cache update events

From: Parav Pandit <[email protected]>

Currently when low level driver notifies Pkey, GID, port change events, they are notified to the registered handlers in the order they are registered.
IB core and other ULPs such as IPoIB are interested in GID, LID, Pkey change events.
Since all GID query done by ULPs is serviced by IB core, in below flow when GID change event occurs, IB core is yet to update the GID cache when IPoIB queries the GID, resulting into not updating IPoIB address.

mlx5_ib_handle_event()
ib_dispatch_event()

    ib_cache_event()
       queue_work() -> slow cache update

    [..]
    ipoib_event()
     queue_work()
       [..]
       work handler
         ipoib_ib_dev_flush_light()
           __ipoib_ib_dev_flush()
              ipoib_dev_addr_changed_valid()
                rdma_query_gid() <- Returns old GID, cache not updated.

Hence, all events which require cache update are handled first by the IB core. Once cache update work is completed, IB core distributes the event to subscriber clients.

Fixes f35faa4ba956 ("IB/core: Simplify ib_query_gid to always refer to cache")
---
 drivers/infiniband/core/cache.c     | 94 +++++++++++++++--------------
 drivers/infiniband/core/core_priv.h |  3 +
 drivers/infiniband/core/device.c    | 26 +++++---
 include/rdma/ib_verbs.h             |  1 -
 4 files changed, 69 insertions(+), 55 deletions(-)
drivers/infiniband/core/cache.c +49 -45
index 00fb3eacda19..46dba17b385d 100644
@@ -51,9 +51,8 @@ struct ib_pkey_cache {
 
 struct ib_update_work {
 	struct work_struct work;
-	struct ib_device  *device;
-	u8                 port_num;
-	bool		   enforce_security;
+	struct ib_event event;
+	bool enforce_security;
 };
 
 union ib_gid zgid;
@@ -130,7 +129,7 @@ static void dispatch_gid_change_event(struct ib_device *ib_dev, u8 port)
 	event.element.port_num	= port;
 	event.event		= IB_EVENT_GID_CHANGE;
 
-	ib_dispatch_event(&event);
+	ib_dispatch_cache_event_clients(&event);
 }
 
 static const char * const gid_type_str[] = {
@@ -1387,9 +1386,8 @@ static int config_non_roce_gid_cache(struct ib_device *device,
 	return ret;
 }
 
-static void ib_cache_update(struct ib_device *device,
-			    u8                port,
-			    bool	      enforce_security)
+static int
+ib_cache_update(struct ib_device *device, u8 port, bool	enforce_security)
 {
 	struct ib_port_attr       *tprops = NULL;
 	struct ib_pkey_cache      *pkey_cache = NULL, *old_pkey_cache;
@@ -1397,11 +1395,11 @@ static void ib_cache_update(struct ib_device *device,
 	int                        ret;
 
 	if (!rdma_is_port_valid(device, port))
-		return;
+		return -EINVAL;
 
 	tprops = kmalloc(sizeof *tprops, GFP_KERNEL);
 	if (!tprops)
-		return;
+		return -ENOMEM;
 
 	ret = ib_query_port(device, port, tprops);
 	if (ret) {
@@ -1419,8 +1417,10 @@ static void ib_cache_update(struct ib_device *device,
 	pkey_cache = kmalloc(struct_size(pkey_cache, table,
 					 tprops->pkey_tbl_len),
 			     GFP_KERNEL);
-	if (!pkey_cache)
+	if (!pkey_cache) {
+		ret = -ENOMEM;
 		goto err;
+	}
 
 	pkey_cache->table_len = tprops->pkey_tbl_len;
 
@@ -1452,49 +1452,58 @@ static void ib_cache_update(struct ib_device *device,
 
 	kfree(old_pkey_cache);
 	kfree(tprops);
-	return;
+	return 0;
 
 err:
 	kfree(pkey_cache);
 	kfree(tprops);
+	return ret;
 }
 
 static void ib_cache_task(struct work_struct *_work)
 {
 	struct ib_update_work *work =
 		container_of(_work, struct ib_update_work, work);
+	int ret;
+
+	ret = ib_cache_update(work->event.device, work->event.element.port_num,
+			      work->enforce_security);
+
+	/* GID event is notified already for individual GID entries by
+	 * dispatch_gid_change_event(). Hence, notifiy for rest of the
+	 * events.
+	 */
+	if (!ret && work->event.event != IB_EVENT_GID_CHANGE)
+		ib_dispatch_cache_event_clients(&work->event);
 
-	ib_cache_update(work->device,
-			work->port_num,
-			work->enforce_security);
 	kfree(work);
 }
 
-static void ib_cache_event(struct ib_event_handler *handler,
-			   struct ib_event *event)
+bool ib_is_cache_update_event(const struct ib_event *event)
+{
+	return (event->event == IB_EVENT_PORT_ERR    ||
+		event->event == IB_EVENT_PORT_ACTIVE ||
+		event->event == IB_EVENT_LID_CHANGE  ||
+		event->event == IB_EVENT_PKEY_CHANGE ||
+		event->event == IB_EVENT_CLIENT_REREGISTER ||
+		event->event == IB_EVENT_GID_CHANGE);
+}
+
+void ib_enqueue_cache_update_event(const struct ib_event *event)
 {
 	struct ib_update_work *work;
 
-	if (event->event == IB_EVENT_PORT_ERR    ||
-	    event->event == IB_EVENT_PORT_ACTIVE ||
-	    event->event == IB_EVENT_LID_CHANGE  ||
-	    event->event == IB_EVENT_PKEY_CHANGE ||
-	    event->event == IB_EVENT_CLIENT_REREGISTER ||
-	    event->event == IB_EVENT_GID_CHANGE) {
-		work = kmalloc(sizeof *work, GFP_ATOMIC);
-		if (work) {
-			INIT_WORK(&work->work, ib_cache_task);
-			work->device   = event->device;
-			work->port_num = event->element.port_num;
-			if (event->event == IB_EVENT_PKEY_CHANGE ||
-			    event->event == IB_EVENT_GID_CHANGE)
-				work->enforce_security = true;
-			else
-				work->enforce_security = false;
-
-			queue_work(ib_wq, &work->work);
-		}
-	}
+	work = kzalloc(sizeof(*work), GFP_ATOMIC);
+	if (!work)
+		return;
+
+	INIT_WORK(&work->work, ib_cache_task);
+	work->event = *event;
+	if (event->event == IB_EVENT_PKEY_CHANGE ||
+	    event->event == IB_EVENT_GID_CHANGE)
+		work->enforce_security = true;
+
+	queue_work(ib_wq, &work->work);
 }
 
 int ib_cache_setup_one(struct ib_device *device)
@@ -1511,9 +1520,6 @@ int ib_cache_setup_one(struct ib_device *device)
 	rdma_for_each_port (device, p)
 		ib_cache_update(device, p, true);
 
-	INIT_IB_EVENT_HANDLER(&device->cache.event_handler,
-			      device, ib_cache_event);
-	ib_register_event_handler(&device->cache.event_handler);
 	return 0;
 }
 
@@ -1535,14 +1541,12 @@ void ib_cache_release_one(struct ib_device *device)
 
 void ib_cache_cleanup_one(struct ib_device *device)
 {
-	/* The cleanup function unregisters the event handler,
-	 * waits for all in-progress workqueue elements and cleans
-	 * up the GID cache. This function should be called after
-	 * the device was removed from the devices list and all
-	 * clients were removed, so the cache exists but is
+	/* The cleanup function waits for all in-progress workqueue
+	 * elements and cleans up the GID cache. This function should be
+	 * called after the device was removed from the devices list and
+	 * all clients were removed, so the cache exists but is
 	 * non-functional and shouldn't be updated anymore.
 	 */
-	ib_unregister_event_handler(&device->cache.event_handler);
 	flush_workqueue(ib_wq);
 	gid_table_cleanup_one(device);
 
drivers/infiniband/core/core_priv.h +3 -0
index 9d07378b5b42..b08018a8cf74 100644
@@ -149,6 +149,9 @@ unsigned long roce_gid_type_mask_support(struct ib_device *ib_dev, u8 port);
 int ib_cache_setup_one(struct ib_device *device);
 void ib_cache_cleanup_one(struct ib_device *device);
 void ib_cache_release_one(struct ib_device *device);
+bool ib_is_cache_update_event(const struct ib_event *event);
+void ib_enqueue_cache_update_event(const struct ib_event *event);
+void ib_dispatch_cache_event_clients(struct ib_event *event);
 
 #ifdef CONFIG_CGROUP_RDMA
 void ib_device_register_rdmacg(struct ib_device *device);
drivers/infiniband/core/device.c +17 -9
index 2f89c4d64b73..e9ab1289c224 100644
@@ -1951,15 +1951,7 @@ void ib_unregister_event_handler(struct ib_event_handler *event_handler)
 }
 EXPORT_SYMBOL(ib_unregister_event_handler);
 
-/**
- * ib_dispatch_event - Dispatch an asynchronous event
- * @event:Event to dispatch
- *
- * Low-level drivers must call ib_dispatch_event() to dispatch the
- * event to all registered event handlers when an asynchronous event
- * occurs.
- */
-void ib_dispatch_event(struct ib_event *event)
+void ib_dispatch_cache_event_clients(struct ib_event *event)
 {
 	unsigned long flags;
 	struct ib_event_handler *handler;
@@ -1971,6 +1963,22 @@ void ib_dispatch_event(struct ib_event *event)
 
 	spin_unlock_irqrestore(&event->device->event_handler_lock, flags);
 }
+
+/**
+ * ib_dispatch_event - Dispatch an asynchronous event
+ * @event:Event to dispatch
+ *
+ * Low-level drivers must call ib_dispatch_event() to dispatch the
+ * event to all registered event handlers when an asynchronous event
+ * occurs.
+ */
+void ib_dispatch_event(struct ib_event *event)
+{
+	if (ib_is_cache_update_event(event))
+		ib_enqueue_cache_update_event(event);
+	else
+		ib_dispatch_cache_event_clients(event);
+}
 EXPORT_SYMBOL(ib_dispatch_event);
 
 static int iw_query_port(struct ib_device *device,
include/rdma/ib_verbs.h +0 -1
index cca9985b4cbc..1f6d6734f477 100644
@@ -2148,7 +2148,6 @@ struct ib_port_cache {
 
 struct ib_cache {
 	rwlock_t                lock;
-	struct ib_event_handler event_handler;
 };
 
 struct ib_port_immutable {

--
2.20.1

#2 lore raw

Re: [PATCH rdma-next 1/3] IB/core: Let IB core distribute cache update events

Quoted 8 lines · Leon Romanovsky
drivers/infiniband/core/device.c +1 -1
index 2f89c4d64b73..e9ab1289c224 100644
+++ b/drivers/infiniband/core/device.c
@@ -1951,15 +1951,7 @@ void ib_unregister_event_handler(struct ib_event_handler *event_handler)
 }
 EXPORT_SYMBOL(ib_unregister_event_handler);
 
-/**

drivers/infiniband/core/device.c void ib_unregister_event_handler(struct ib_event_handler *event_handler) · line 1955

Quoted 10 lines
drivers/infiniband/core/device.c +1 -8
- * ib_dispatch_event - Dispatch an asynchronous event
- * @event:Event to dispatch
- *
- * Low-level drivers must call ib_dispatch_event() to dispatch the
- * event to all registered event handlers when an asynchronous event
- * occurs.
- */
-void ib_dispatch_event(struct ib_event *event)
+void ib_dispatch_cache_event_clients(struct ib_event *event)
 {

no kdoc for this?

Quoted 13 lines
drivers/infiniband/core/device.c +7 -0
 	unsigned long flags;
 	struct ib_event_handler *handler;
@@ -1971,6 +1963,22 @@ void ib_dispatch_event(struct ib_event *event)
 
 	spin_unlock_irqrestore(&event->device->event_handler_lock, flags);
 }
+
+/**
+ * ib_dispatch_event - Dispatch an asynchronous event
+ * @event:Event to dispatch
+ *
+ * Low-level drivers must call ib_dispatch_event() to dispatch the
+ * event to all registered event handlers when an asynchronous event

drivers/infiniband/core/device.c void ib_dispatch_event(struct ib_event *event) · line 1982

Quoted 10 lines
drivers/infiniband/core/device.c +9 -0
+ * occurs.
+ */
+void ib_dispatch_event(struct ib_event *event)
+{
+	if (ib_is_cache_update_event(event))
+		ib_enqueue_cache_update_event(event);
+	else
+		ib_dispatch_cache_event_clients(event);
+}
 EXPORT_SYMBOL(ib_dispatch_event);

It seems like there is now some big mess here, many of the users of events, including cache, acctually do need a blocking context to do their work, while this function is supposed to be atomic context for the driver.

So, after this change, many event types are now guarenteed to be called from a blocking context in a WQ - but we still go ahead and do silly things like launch more work to get into blocking contexts from the other users

Thus I'm wondering if this wouldn't be better off just always pushing events into a wq and running the notifier subscriptions sequentially?

Jason

#3 lore raw

RE: [PATCH rdma-next 1/3] IB/core: Let IB core distribute cache update events

Quoted 22 lines

-----Original Message-----
From: Jason Gunthorpe <[email protected]>
Sent: Tuesday, October 22, 2019 2:55 PM
To: Leon Romanovsky <[email protected]>
Cc: Doug Ledford <[email protected]>; Leon Romanovsky <[email protected]>; RDMA mailing list <[email protected]>; Daniel Jurgens <[email protected]>; Parav Pandit <[email protected]>
Subject: Re: [PATCH rdma-next 1/3] IB/core: Let IB core distribute cache update events

Quoted 8 lines · Leon Romanovsky
drivers/infiniband/core/device.c +1 -0
index 2f89c4d64b73..e9ab1289c224 100644
+++ b/drivers/infiniband/core/device.c
@@ -1951,15 +1951,7 @@ void ib_unregister_event_handler(struct
 ib_event_handler *event_handler)  }
 EXPORT_SYMBOL(ib_unregister_event_handler);
 
Quoted 14 lines

drivers/infiniband/core/device.c void ib_unregister_event_handler(struct ib_event_handler *event_handler) · line 1955

Quoted 11 lines
drivers/infiniband/core/device.c +1 -9
-/**
- * ib_dispatch_event - Dispatch an asynchronous event
- * @event:Event to dispatch
- *
- * Low-level drivers must call ib_dispatch_event() to dispatch the
- * event to all registered event handlers when an asynchronous event
- * occurs.
- */
-void ib_dispatch_event(struct ib_event *event)
+void ib_dispatch_cache_event_clients(struct ib_event *event)
 {

no kdoc for this?

I dropped the kdoc because it was an internal API, not exposed to other kernel modules.
And added for the external one below.

Quoted 27 lines
Quoted 12 lines
drivers/infiniband/core/device.c +6 -0
 	unsigned long flags;
 	struct ib_event_handler *handler;
@@ -1971,6 +1963,22 @@ void ib_dispatch_event(struct ib_event *event)
 
 	spin_unlock_irqrestore(&event->device->event_handler_lock, flags);
 }
+
+/**
+ * ib_dispatch_event - Dispatch an asynchronous event
+ * @event:Event to dispatch
+ *
+ * Low-level drivers must call ib_dispatch_event() to dispatch the

drivers/infiniband/core/device.c void ib_dispatch_event(struct ib_event *event) · line 1981

Quoted 10 lines
drivers/infiniband/core/device.c +9 -0
+ * event to all registered event handlers when an asynchronous event
+ * occurs.
+ */
+void ib_dispatch_event(struct ib_event *event) {
+	if (ib_is_cache_update_event(event))
+		ib_enqueue_cache_update_event(event);
+	else
+		ib_dispatch_cache_event_clients(event);
+}
 EXPORT_SYMBOL(ib_dispatch_event);

It seems like there is now some big mess here, many of the users of events, including cache, acctually do need a blocking context to do their work, while this function is supposed to be atomic context for the driver.

Quoted 7 lines

So, after this change, many event types are now guarenteed to be called from a blocking context in a WQ - but we still go ahead and do silly things like launch more work to get into blocking contexts from the other users

Thus I'm wondering if this wouldn't be better off just always pushing events into a wq and running the notifier subscriptions sequentially?

Are you saying we should drop the else part above and always do ib_enqueue_cache_update_event()? If so, yes, I think it should be fine.
Only event that I wanted to deliver faster was IB_EVENT_SRQ_LIMIT_REACHED.
However given no kernel consumer interested in it, doing fast event delivery for such event is not so useful. We can slim down ib_is_cache_update_event().

#4 lore raw

Re: [PATCH rdma-next 1/3] IB/core: Let IB core distribute cache update events

Quoted 31 lines · Parav Pandit
Quoted 31 lines
Quoted 12 lines
drivers/infiniband/core/device.c +6 -0
 	unsigned long flags;
 	struct ib_event_handler *handler;
@@ -1971,6 +1963,22 @@ void ib_dispatch_event(struct ib_event *event)
 
 	spin_unlock_irqrestore(&event->device->event_handler_lock, flags);
 }
+
+/**
+ * ib_dispatch_event - Dispatch an asynchronous event
+ * @event:Event to dispatch
+ *
+ * Low-level drivers must call ib_dispatch_event() to dispatch the

drivers/infiniband/core/device.c void ib_dispatch_event(struct ib_event *event) · line 1981

Quoted 10 lines
drivers/infiniband/core/device.c +9 -0
+ * event to all registered event handlers when an asynchronous event
+ * occurs.
+ */
+void ib_dispatch_event(struct ib_event *event) {
+	if (ib_is_cache_update_event(event))
+		ib_enqueue_cache_update_event(event);
+	else
+		ib_dispatch_cache_event_clients(event);
+}
 EXPORT_SYMBOL(ib_dispatch_event);

It seems like there is now some big mess here, many of the users of events, including cache, acctually do need a blocking context to do their work, while this function is supposed to be atomic context for the driver.

So, after this change, many event types are now guarenteed to be called from a blocking context in a WQ - but we still go ahead and do silly things like launch more work to get into blocking contexts from the other users

Quoted 5 lines
Quoted 3 lines

Thus I'm wondering if this wouldn't be better off just always pushing events into a wq and running the notifier subscriptions sequentially?

Are you saying we should drop the else part above and always do ib_enqueue_cache_update_event()?

Yes, but also now saying that all notifier callbacks are called from work queues and can block for short periods.

This seems it would simplify many of the users??

And not using the ib_enqueue_cache_update_event() but a simple blocking_notifier_call_chain() with the cache always at the front

Quoted 2 lines

Only event that I wanted to deliver faster was
IB_EVENT_SRQ_LIMIT_REACHED.

It might make sense to have an atomic event list for such things in future..

Jason

#5 lore raw

RE: [PATCH rdma-next 1/3] IB/core: Let IB core distribute cache update events

Quoted 53 lines

-----Original Message-----
From: Jason Gunthorpe <[email protected]>
Sent: Wednesday, October 23, 2019 12:41 PM
To: Parav Pandit <[email protected]>
Cc: Leon Romanovsky <[email protected]>; Doug Ledford <[email protected]>; Leon Romanovsky <[email protected]>; RDMA mailing list <[email protected]>; Daniel Jurgens <[email protected]>
Subject: Re: [PATCH rdma-next 1/3] IB/core: Let IB core distribute cache update events

Quoted 20 lines · Parav Pandit
Quoted 20 lines
Quoted 20 lines
(quoted diff) +0 -0
 	unsigned long flags;
 	struct ib_event_handler *handler; @@ -1971,6 +1963,22 @@ void

ib_dispatch_event(struct ib_event *event)

spin_unlock_irqrestore(&event->device->event_handler_lock,
flags); }

drivers/infiniband/core/device.c +14 -0
+
+/**
+ * ib_dispatch_event - Dispatch an asynchronous event
+ * @event:Event to dispatch
+ *
+ * Low-level drivers must call ib_dispatch_event() to dispatch
+the
+ * event to all registered event handlers when an asynchronous
+event
+ * occurs.
+ */
+void ib_dispatch_event(struct ib_event *event) {
+	if (ib_is_cache_update_event(event))
+		ib_enqueue_cache_update_event(event);
Quoted 8 lines
Quoted 8 lines

drivers/infiniband/core/device.c void ib_dispatch_event(struct ib_event *event) · line 1982

Quoted 4 lines
drivers/infiniband/core/device.c +3 -0
+	else
+		ib_dispatch_cache_event_clients(event);
+}
 EXPORT_SYMBOL(ib_dispatch_event);

It seems like there is now some big mess here, many of the users of events, including cache, acctually do need a blocking context to do their work, while this function is supposed to be atomic context for the

driver.

Quoted 8 lines
Quoted 8 lines

So, after this change, many event types are now guarenteed to be called from a blocking context in a WQ - but we still go ahead and do silly things like launch more work to get into blocking contexts from the other users

Thus I'm wondering if this wouldn't be better off just always pushing events into a wq and running the notifier subscriptions

sequentially?

Quoted 1 line
Quoted 1 line
Quoted 8 lines
Quoted 2 lines

Are you saying we should drop the else part above and always do ib_enqueue_cache_update_event()?

Yes, but also now saying that all notifier callbacks are called from work queues and can block for short periods.

This seems it would simplify many of the users??

Yes, however that optimization should be a different series per ULP/consumer/event based. Will send v1 through Leon's queue.

Quoted 8 lines

And not using the ib_enqueue_cache_update_event() but a simple blocking_notifier_call_chain() with the cache always at the front

Quoted 2 lines

Only event that I wanted to deliver faster was
IB_EVENT_SRQ_LIMIT_REACHED.

It might make sense to have an atomic event list for such things in future..

Ok.

Quoted 1 line

Jason

#6 lore raw

PATCH 2/3 IB/core: Cut down single member ib_cache structure

In reply to Leon Romanovsky

From: Parav Pandit <[email protected]>

Given that ib_cache structure has only single member now, merge the cache lock directly in the ib_device.

---
 drivers/infiniband/core/cache.c | 30 +++++++++++++++---------------
 include/rdma/ib_verbs.h         |  7 ++-----
 2 files changed, 17 insertions(+), 20 deletions(-)
drivers/infiniband/core/cache.c +15 -15
index 46dba17b385d..b626ca682004 100644
@@ -1039,7 +1039,7 @@ int ib_get_cached_pkey(struct ib_device *device,
 	if (!rdma_is_port_valid(device, port_num))
 		return -EINVAL;
 
-	read_lock_irqsave(&device->cache.lock, flags);
+	read_lock_irqsave(&device->cache_lock, flags);
 
 	cache = device->port_data[port_num].cache.pkey;
 
@@ -1048,7 +1048,7 @@ int ib_get_cached_pkey(struct ib_device *device,
 	else
 		*pkey = cache->table[index];
 
-	read_unlock_irqrestore(&device->cache.lock, flags);
+	read_unlock_irqrestore(&device->cache_lock, flags);
 
 	return ret;
 }
@@ -1063,9 +1063,9 @@ int ib_get_cached_subnet_prefix(struct ib_device *device,
 	if (!rdma_is_port_valid(device, port_num))
 		return -EINVAL;
 
-	read_lock_irqsave(&device->cache.lock, flags);
+	read_lock_irqsave(&device->cache_lock, flags);
 	*sn_pfx = device->port_data[port_num].cache.subnet_prefix;
-	read_unlock_irqrestore(&device->cache.lock, flags);
+	read_unlock_irqrestore(&device->cache_lock, flags);
 
 	return 0;
 }
@@ -1085,7 +1085,7 @@ int ib_find_cached_pkey(struct ib_device *device,
 	if (!rdma_is_port_valid(device, port_num))
 		return -EINVAL;
 
-	read_lock_irqsave(&device->cache.lock, flags);
+	read_lock_irqsave(&device->cache_lock, flags);
 
 	cache = device->port_data[port_num].cache.pkey;
 
@@ -1106,7 +1106,7 @@ int ib_find_cached_pkey(struct ib_device *device,
 		ret = 0;
 	}
 
-	read_unlock_irqrestore(&device->cache.lock, flags);
+	read_unlock_irqrestore(&device->cache_lock, flags);
 
 	return ret;
 }
@@ -1125,7 +1125,7 @@ int ib_find_exact_cached_pkey(struct ib_device *device,
 	if (!rdma_is_port_valid(device, port_num))
 		return -EINVAL;
 
-	read_lock_irqsave(&device->cache.lock, flags);
+	read_lock_irqsave(&device->cache_lock, flags);
 
 	cache = device->port_data[port_num].cache.pkey;
 
@@ -1138,7 +1138,7 @@ int ib_find_exact_cached_pkey(struct ib_device *device,
 			break;
 		}
 
-	read_unlock_irqrestore(&device->cache.lock, flags);
+	read_unlock_irqrestore(&device->cache_lock, flags);
 
 	return ret;
 }
@@ -1154,9 +1154,9 @@ int ib_get_cached_lmc(struct ib_device *device,
 	if (!rdma_is_port_valid(device, port_num))
 		return -EINVAL;
 
-	read_lock_irqsave(&device->cache.lock, flags);
+	read_lock_irqsave(&device->cache_lock, flags);
 	*lmc = device->port_data[port_num].cache.lmc;
-	read_unlock_irqrestore(&device->cache.lock, flags);
+	read_unlock_irqrestore(&device->cache_lock, flags);
 
 	return ret;
 }
@@ -1172,9 +1172,9 @@ int ib_get_cached_port_state(struct ib_device   *device,
 	if (!rdma_is_port_valid(device, port_num))
 		return -EINVAL;
 
-	read_lock_irqsave(&device->cache.lock, flags);
+	read_lock_irqsave(&device->cache_lock, flags);
 	*port_state = device->port_data[port_num].cache.port_state;
-	read_unlock_irqrestore(&device->cache.lock, flags);
+	read_unlock_irqrestore(&device->cache_lock, flags);
 
 	return ret;
 }
@@ -1434,7 +1434,7 @@ ib_cache_update(struct ib_device *device, u8 port, bool	enforce_security)
 		}
 	}
 
-	write_lock_irq(&device->cache.lock);
+	write_lock_irq(&device->cache_lock);
 
 	old_pkey_cache = device->port_data[port].cache.pkey;
 
@@ -1443,7 +1443,7 @@ ib_cache_update(struct ib_device *device, u8 port, bool	enforce_security)
 	device->port_data[port].cache.port_state = tprops->state;
 
 	device->port_data[port].cache.subnet_prefix = tprops->subnet_prefix;
-	write_unlock_irq(&device->cache.lock);
+	write_unlock_irq(&device->cache_lock);
 
 	if (enforce_security)
 		ib_security_cache_change(device,
@@ -1511,7 +1511,7 @@ int ib_cache_setup_one(struct ib_device *device)
 	unsigned int p;
 	int err;
 
-	rwlock_init(&device->cache.lock);
+	rwlock_init(&device->cache_lock);
 
 	err = gid_table_setup_one(device);
 	if (err)
include/rdma/ib_verbs.h +2 -5
index 1f6d6734f477..adff05eade2c 100644
@@ -2146,10 +2146,6 @@ struct ib_port_cache {
 	enum ib_port_state     port_state;
 };
 
-struct ib_cache {
-	rwlock_t                lock;
-};
-
 struct ib_port_immutable {
 	int                           pkey_tbl_len;
 	int                           gid_tbl_len;
@@ -2609,7 +2605,8 @@ struct ib_device {
 	struct xarray                 client_data;
 	struct mutex                  unregistration_lock;
 
-	struct ib_cache               cache;
+	/* Synchronize GID, Pkey cache entries, subnet prefix, LMC */
+	rwlock_t cache_lock;
 	/**
 	 * port_data is indexed by port number
 	 */

--
2.20.1

#7 lore raw

PATCH 3/3 IB/core: Do not notify GID change event of an unregistered device

In reply to Leon Romanovsky

From: Parav Pandit <[email protected]>

When IB device is undergoing unregistration, GID cache is cleaned up after all clients are unregistered in below flow.

__ib_unregister_device()
disable_device();
ib_cache_cleanup_one()
gid_table_cleanup_one()
cleanup_gid_table_port()

There is no use of generating a GID change event at such stage, where there is no active client of the device and device is unregistered state.

---
 drivers/infiniband/core/cache.c | 8 +-------
 1 file changed, 1 insertion(+), 7 deletions(-)
drivers/infiniband/core/cache.c +1 -7
index b626ca682004..53d8313e8309 100644
@@ -818,22 +818,16 @@ static void cleanup_gid_table_port(struct ib_device *ib_dev, u8 port,
 				   struct ib_gid_table *table)
 {
 	int i;
-	bool deleted = false;
 
 	if (!table)
 		return;
 
 	mutex_lock(&table->lock);
 	for (i = 0; i < table->sz; ++i) {
-		if (is_gid_entry_valid(table->data_vec[i])) {
+		if (is_gid_entry_valid(table->data_vec[i]))
 			del_gid(ib_dev, port, table, i);
-			deleted = true;
-		}
 	}
 	mutex_unlock(&table->lock);
-
-	if (deleted)
-		dispatch_gid_change_event(ib_dev, port);
 }
 
 void ib_cache_gid_set_default_gid(struct ib_device *ib_dev, u8 port,

--
2.20.1

#8 lore raw

Re: [PATCH rdma-next 3/3] IB/core: Do not notify GID change event of an unregistered device

Quoted 15 lines · Leon Romanovsky

From: Parav Pandit <[email protected]>

When IB device is undergoing unregistration, GID cache is cleaned up after all clients are unregistered in below flow.

__ib_unregister_device()
disable_device();
ib_cache_cleanup_one()
gid_table_cleanup_one()
cleanup_gid_table_port()

There is no use of generating a GID change event at such stage, where there is no active client of the device and device is unregistered state.

Quoted 7 lines
---
 drivers/infiniband/core/cache.c | 8 +-------
 1 file changed, 1 insertion(+), 7 deletions(-)

Yep, this is a consequence of the recent cleanups in device. Applied to for-next

Jason