Patch "[PATCH 014/135] ixgbe: Fix handling of NAPI budget when multiple" has been added to the 4.4-stable tree

Patch "[PATCH 014/135] ixgbe: Fix handling of NAPI budget when multiple" has been added to the 4.4-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    [PATCH 014/135] ixgbe: Fix handling of NAPI budget when multiple

to the 4.4-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:
     0014-ixgbe-Fix-handling-of-NAPI-budget-when-multiple-queu.patch
and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 280b3ddc982e0cfc9f508d24ad0d465912591c53 Mon Sep 17 00:00:00 2001
From: Alexander Duyck <aduyck@mirantis.com>
Date: Tue, 22 Sep 2015 14:35:41 -0700
Subject: [PATCH 014/135] ixgbe: Fix handling of NAPI budget when multiple
 queues are enabled per vector

[ Upstream commit 5d6002b7b822c7423e75d4651e6790bfb5642b1b ]

This patch corrects an issue in which the polling routine would increase
the budget for Rx to at least 1 per queue if multiple queues were present.
This would result in Rx packets being processed when the budget was 0 which
is meant to indicate that no Rx can be handled.

Signed-off-by: Alexander Duyck <aduyck@mirantis.com>
Tested-by: Darin Miller <darin.j.miller@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/net/ethernet/intel/ixgbe/ixgbe_main.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
@@ -2786,7 +2786,8 @@ int ixgbe_poll(struct napi_struct *napi,
 	ixgbe_for_each_ring(ring, q_vector->tx)
 		clean_complete &= !!ixgbe_clean_tx_irq(q_vector, ring);
 
-	if (!ixgbe_qv_lock_napi(q_vector))
+	/* Exit if we are called by netpoll or busy polling is active */
+	if ((budget <= 0) || !ixgbe_qv_lock_napi(q_vector))
 		return budget;
 
 	/* attempt to distribute budget to each queue fairly, but don't allow


Patches currently in stable-queue which might be from aduyck@mirantis.com are

queue-4.4/0014-ixgbe-Fix-handling-of-NAPI-budget-when-multiple-queu.patch
queue-4.4/0025-fm10k-Cleanup-exception-handling-for-mailbox-interru.patch
queue-4.4/0020-fm10k-Fix-handling-of-NAPI-budget-when-multiple-queu.patch
queue-4.4/0024-fm10k-Cleanup-MSI-X-interrupts-in-case-of-failure.patch