From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Gallatin Subject: Re: CPU utilization increased in 2.6.27rc Date: Wed, 13 Aug 2008 12:13:40 -0400 Message-ID: <48A30834.4090802@myri.com> References: <48A23137.2010107@myri.com> <20080812.181549.229367205.davem@davemloft.net> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, robert@robur.slu.se To: David Miller Return-path: Received: from mailbox2.myri.com ([64.172.73.26]:1965 "EHLO myri.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752912AbYHMQVR (ORCPT ); Wed, 13 Aug 2008 12:21:17 -0400 In-Reply-To: <20080812.181549.229367205.davem@davemloft.net> Sender: netdev-owner@vger.kernel.org List-ID: David Miller wrote: > From: Andrew Gallatin > Date: Tue, 12 Aug 2008 20:56:23 -0400 > >> pkt_sched: Schedule qdiscs instead of netdev_queue. > > While I'm waiting for your beforehand profile data, > here is a stab in the dark patch which might fix > the problem. > > Robert, this could explain some of the things in the > multiqueue testing profile you sent me a week or so > ago. > > Let me know how well it works: Excellent! This completely fixes the increased CPU utilization I observed on both 10GbE and 1GbE interfaces, and CPU utilization is now reduced back to 2.6.26 levels. Oprofile now is nearly identical to what it was prior to 37437bb2e1ae8af470dfcd5b4ff454110894ccaf: 8363 6.5081 vmlinux _raw_spin_lock 5612 4.3672 oprofiled (no symbols) 4420 3.4396 ehci_hcd (no symbols) 4325 3.3657 vmlinux handle_IRQ_event 3688 2.8700 vmlinux default_idle 3164 2.4622 vmlinux nv_start_xmit_optimized 3092 2.4062 vmlinux sk_run_filter 3072 2.3906 vmlinux tcp_ack 2969 2.3105 vmlinux __copy_skb_header 2453 1.9089 vmlinux kmem_cache_free 2400 1.8677 vmlinux IRQ0x69_interrupt 2295 1.7860 vmlinux nv_rx_process_optimized 2092 1.6280 vmlinux kmem_cache_alloc 2072 1.6124 vmlinux kfree 2049 1.5945 vmlinux packet_rcv_spkt 1984 1.5439 vmlinux __tcp_push_pending_frames 1942 1.5113 vmlinux nv_nic_irq_optimized 1933 1.5043 vmlinux _raw_spin_unlock 1637 1.2739 vmlinux nv_tx_done_optimized 1630 1.2685 vmlinux eth_type_trans 1517 1.1805 vmlinux __qdisc_run Thank you, Drew