4.4-stable patches

added patches:
	dmaengine-at_xdmac-don-t-start-transactions-at-tx_submit-level.patch
	netns-add-schedule-point-in-ops_exit_list.patch

diff --git a/queue-4.4/dmaengine-at_xdmac-don-t-start-transactions-at-tx_submit-level.patch b/queue-4.4/dmaengine-at_xdmac-don-t-start-transactions-at-tx_submit-level.patch
new file mode 100644 (file)
index 0000000..5f76a58
--- /dev/null
+++ b/queue-4.4/dmaengine-at_xdmac-don-t-start-transactions-at-tx_submit-level.patch
@@ -0,0 +1,53 @@
+From bccfb96b59179d4f96cbbd1ddff8fac6d335eae4 Mon Sep 17 00:00:00 2001
+From: Tudor Ambarus <tudor.ambarus@microchip.com>
+Date: Wed, 15 Dec 2021 13:01:04 +0200
+Subject: dmaengine: at_xdmac: Don't start transactions at tx_submit level
+
+From: Tudor Ambarus <tudor.ambarus@microchip.com>
+
+commit bccfb96b59179d4f96cbbd1ddff8fac6d335eae4 upstream.
+
+tx_submit is supposed to push the current transaction descriptor to a
+pending queue, waiting for issue_pending() to be called. issue_pending()
+must start the transfer, not tx_submit(), thus remove
+at_xdmac_start_xfer() from at_xdmac_tx_submit(). Clients of at_xdmac that
+assume that tx_submit() starts the transfer must be updated and call
+dma_async_issue_pending() if they miss to call it (one example is
+atmel_serial).
+
+As the at_xdmac_start_xfer() is now called only from
+at_xdmac_advance_work() when !at_xdmac_chan_is_enabled(), the
+at_xdmac_chan_is_enabled() check is no longer needed in
+at_xdmac_start_xfer(), thus remove it.
+
+Fixes: e1f7c9eee707 ("dmaengine: at_xdmac: creation of the atmel eXtended DMA Controller driver")
+Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
+Link: https://lore.kernel.org/r/20211215110115.191749-2-tudor.ambarus@microchip.com
+Signed-off-by: Vinod Koul <vkoul@kernel.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ drivers/dma/at_xdmac.c |    6 ------
+ 1 file changed, 6 deletions(-)
+
+--- a/drivers/dma/at_xdmac.c
++++ b/drivers/dma/at_xdmac.c
+@@ -345,9 +345,6 @@ static void at_xdmac_start_xfer(struct a
+ 
+       dev_vdbg(chan2dev(&atchan->chan), "%s: desc 0x%p\n", __func__, first);
+ 
+-      if (at_xdmac_chan_is_enabled(atchan))
+-              return;
+-
+       /* Set transfer as active to not try to start it again. */
+       first->active_xfer = true;
+ 
+@@ -431,9 +428,6 @@ static dma_cookie_t at_xdmac_tx_submit(s
+       dev_vdbg(chan2dev(tx->chan), "%s: atchan 0x%p, add desc 0x%p to xfers_list\n",
+                __func__, atchan, desc);
+       list_add_tail(&desc->xfer_node, &atchan->xfers_list);
+-      if (list_is_singular(&atchan->xfers_list))
+-              at_xdmac_start_xfer(atchan, desc);
+-
+       spin_unlock_irqrestore(&atchan->lock, irqflags);
+       return cookie;
+ }

diff --git a/queue-4.4/netns-add-schedule-point-in-ops_exit_list.patch b/queue-4.4/netns-add-schedule-point-in-ops_exit_list.patch
new file mode 100644 (file)
index 0000000..450f945
--- /dev/null
+++ b/queue-4.4/netns-add-schedule-point-in-ops_exit_list.patch
@@ -0,0 +1,47 @@
+From 2836615aa22de55b8fca5e32fe1b27a67cda625e Mon Sep 17 00:00:00 2001
+From: Eric Dumazet <edumazet@google.com>
+Date: Tue, 18 Jan 2022 03:43:40 -0800
+Subject: netns: add schedule point in ops_exit_list()
+
+From: Eric Dumazet <edumazet@google.com>
+
+commit 2836615aa22de55b8fca5e32fe1b27a67cda625e upstream.
+
+When under stress, cleanup_net() can have to dismantle
+netns in big numbers. ops_exit_list() currently calls
+many helpers [1] that have no schedule point, and we can
+end up with soft lockups, particularly on hosts
+with many cpus.
+
+Even for moderate amount of netns processed by cleanup_net()
+this patch avoids latency spikes.
+
+[1] Some of these helpers like fib_sync_up() and fib_sync_down_dev()
+are very slow because net/ipv4/fib_semantics.c uses host-wide hash tables,
+and ifindex is used as the only input of two hash functions.
+    ifindexes tend to be the same for all netns (lo.ifindex==1 per instance)
+    This will be fixed in a separate patch.
+
+Fixes: 72ad937abd0a ("net: Add support for batching network namespace cleanups")
+Signed-off-by: Eric Dumazet <edumazet@google.com>
+Cc: Eric W. Biederman <ebiederm@xmission.com>
+Signed-off-by: David S. Miller <davem@davemloft.net>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ net/core/net_namespace.c |    4 +++-
+ 1 file changed, 3 insertions(+), 1 deletion(-)
+
+--- a/net/core/net_namespace.c
++++ b/net/core/net_namespace.c
+@@ -130,8 +130,10 @@ static void ops_exit_list(const struct p
+ {
+       struct net *net;
+       if (ops->exit) {
+-              list_for_each_entry(net, net_exit_list, exit_list)
++              list_for_each_entry(net, net_exit_list, exit_list) {
+                       ops->exit(net);
++                      cond_resched();
++              }
+       }
+       if (ops->exit_batch)
+               ops->exit_batch(net_exit_list);

diff --git a/queue-4.4/series b/queue-4.4/series
index cb663e07c781649d9eec20928e9869496a7905f0..4bd98ee1cca325269d2db8537b9321c2667e3cd1 100644 (file)
--- a/queue-4.4/series
+++ b/queue-4.4/series
@@ -104,3 +104,5 @@ parisc-pdc_stable-fix-memory-leak-in-pdcs_register_pathentries.patch
 af_unix-annote-lockless-accesses-to-unix_tot_inflight-gc_in_progress.patch
 net-axienet-wait-for-phyrstcmplt-after-core-reset.patch
 net-axienet-fix-number-of-tx-ring-slots-for-available-check.patch
+netns-add-schedule-point-in-ops_exit_list.patch
+dmaengine-at_xdmac-don-t-start-transactions-at-tx_submit-level.patch