also , I see a new feature in 3.3 byte_queue_limits 1.5. Bufferbloat fighting: Byte queue limits https://lwn.net/Articles/454390/ "Bufferbloat" is a term used to describe the latency and throughput problems caused by excessive buffering trough the several elements of a network connection. Some tools are being developed to help to alleviate these problems, and this feature is one of them. Byte queue limits are a configurable limit of packet data that can be put in the transmission queue of a network device. As a result one can tune things such that high priority packets get serviced with a reasonable amount of latency whilst not subjecting the hardware queue to emptying when data is available to send. Configuration of the queue limits is in the tx-<n> sysfs directory for the queue under the byte_queue_limits directory. I see some bug report about spike: http://www.mail-archive.com/e1000-devel@xxxxxxxxxxxxxxxxxxxxx/msg05538.html maybe can you try to play with values in /sys/class/net/eth0/queues/tx-0/byte_queue_limits/* ----- Mail original ----- De: "Alexandre DERUMIER" <aderumier@xxxxxxxxx> À: "Stefan Priebe - Profihost AG" <s.priebe@xxxxxxxxxxxx> Cc: ceph-devel@xxxxxxxxxxxxxxx Envoyé: Lundi 18 Juin 2012 11:21:09 Objet: Re: stable 10GBE under 3.4.2 or 3.5.0-rc2 Did you use same driver version with the differents kernel version ? Maybe try to desactive tso,gso,... with ethtool ? ----- Mail original ----- De: "Stefan Priebe - Profihost AG" <s.priebe@xxxxxxxxxxxx> À: "Alexandre DERUMIER" <aderumier@xxxxxxxxx> Cc: ceph-devel@xxxxxxxxxxxxxxx Envoyé: Lundi 18 Juin 2012 11:11:16 Objet: Re: stable 10GBE under 3.4.2 or 3.5.0-rc2 Am 18.06.2012 10:11, schrieb Alexandre DERUMIER: > maybe try to play with net.ipv4.tcp_congestion_control ? The default on my machines and even under RHEL6 is cubic. But i've now alos tried, reno, bic and highspeed. But it doesn't change anything. Everything is fine under 3.0.32 and pretty bad under 3.4.X or 3.5rc2. Stefan -- -- Alexandre D erumier Ingénieur Système Fixe : 03 20 68 88 90 Fax : 03 20 68 90 81 45 Bvd du Général Leclerc 59100 Roubaix - France 12 rue Marivaux 75002 Paris - France -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html