Patch "xen-netback: respect user provided max_queues" has been added to the 4.1-stable tree

Patch "xen-netback: respect user provided max_queues" has been added to the 4.1-stable tree

[gregkh]

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

    xen-netback: respect user provided max_queues

to the 4.1-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:
     xen-netback-respect-user-provided-max_queues.patch
and it can be found in the queue-4.1 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 foo@baz Tue Jan 26 21:37:04 PST 2016
From: Wei Liu <wei.liu2@citrix.com>
Date: Thu, 10 Sep 2015 11:18:57 +0100
Subject: xen-netback: respect user provided max_queues

From: Wei Liu <wei.liu2@citrix.com>

[ Upstream commit 4c82ac3c37363e8c4ded6a5fe1ec5fa756b34df3 ]

Originally that parameter was always reset to num_online_cpus during
module initialisation, which renders it useless.

The fix is to only set max_queues to num_online_cpus when user has not
provided a value.

Reported-by: Johnny Strom <johnny.strom@linuxsolutions.fi>
Signed-off-by: Wei Liu <wei.liu2@citrix.com>
Reviewed-by: David Vrabel <david.vrabel@citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/net/xen-netback/netback.c |    7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

--- a/drivers/net/xen-netback/netback.c
+++ b/drivers/net/xen-netback/netback.c
@@ -2007,8 +2007,11 @@ static int __init netback_init(void)
 	if (!xen_domain())
 		return -ENODEV;
 
-	/* Allow as many queues as there are CPUs, by default */
-	xenvif_max_queues = num_online_cpus();
+	/* Allow as many queues as there are CPUs if user has not
+	 * specified a value.
+	 */
+	if (xenvif_max_queues == 0)
+		xenvif_max_queues = num_online_cpus();
 
 	if (fatal_skb_slots < XEN_NETBK_LEGACY_SLOTS_MAX) {
 		pr_info("fatal_skb_slots too small (%d), bump it to XEN_NETBK_LEGACY_SLOTS_MAX (%d)\n",


Patches currently in stable-queue which might be from wei.liu2@citrix.com are

queue-4.1/xen-netfront-update-num_queues-to-real-created.patch
queue-4.1/xen-netback-respect-user-provided-max_queues.patch
queue-4.1/xen-netfront-respect-user-provided-max_queues.patch