Patch "IB/core: Fix use workqueue without WQ_MEM_RECLAIM" has been added to the 4.14-stable tree
Subsystems (2)
This is a note to let you know that I've just added the patch titled
IB/core: Fix use workqueue without WQ_MEM_RECLAIM
to the 4.14-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
ib-core-fix-use-workqueue-without-wq_mem_reclaim.patch
and it can be found in the queue-4.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.
Quoted 1 line
From foo@baz Mon Dec 18 13:29:00 CET 2017
From: Parav Pandit <[email protected]>
Date: Mon, 16 Oct 2017 08:45:15 +0300
Subject: IB/core: Fix use workqueue without WQ_MEM_RECLAIM
From: Parav Pandit <[email protected]>
[ Upstream commit 39baf10310e6669564a485b55267fae70a4e44ae ]
The IB/core provides address resolution service and invokes callback handler when address resolve request completes of requester in worker thread context.
Such caller might allocate or free memory in callback handler depending on the completion status to make further progress or to terminate a connection. Most ULPs resolve route which involves allocating route entry and path record elements in callback event handler.
It has been noticed that WQ_MEM_RECLAIM flag should not be used for workers that tend to allocate memory in this [1] thread discussion.
In order to mitigate this situation, WQ_MEM_RECLAIM flag was dropped for other such WQs in this [2] patch.
Similar problem might arise with address resolution path, though its not yet noticed. The ib_addr workqueue is not memory reclaim path due to its nature of invoking callback that might allocate memory or don't free any memory under memory pressure.
[1] https://www.spinics.net/lists/linux-rdma/msg53239.html
[2] https://www.spinics.net/lists/linux-rdma/msg53416.html
--- drivers/infiniband/core/addr.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
drivers/infiniband/core/addr.c +1 -1
@@ -852,7 +852,7 @@ static struct notifier_block nb = {int addr_init (void ) { - addr_wq =alloc_ordered_workqueue ("ib_addr" ,WQ_MEM_RECLAIM ); + addr_wq =alloc_ordered_workqueue ("ib_addr" ,0 );if (!addr_wq)return -ENOMEM ;
Patches currently in stable-queue which might be from [email protected] are
queue-4.14/ib-core-don-t-enforce-pkey-security-on-smi-mads.patch queue-4.14/ib-core-bound-check-alternate-path-port-number.patch queue-4.14/ib-core-fix-calculation-of-maximum-roce-mtu.patch queue-4.14/ib-core-fix-use-workqueue-without-wq_mem_reclaim.patch