Date: Mon, 26 Jul 2004 10:42:01 -0400 From: James <haesu@towardex.com> To: freebsd-net@freebsd.org Subject: device polling takes more CPU hits?? Message-ID: <20040726144201.GA93526@scylla.towardex.com>
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Hi all, I've got a weird case on my hands on a 2.8ghz xeon w/ HTT working as a router w/ device polling... This is a single-processor 2.8ghz xeon, not dual/quad, etc. The kernel does have SMP compiled in though. The box has two gig-e cards, em0 and bge0. bge0 is the uplink to the core, em0 is the downlink to the ethernet switch with 802.1q vlans for customer aggregation. During daytime, the box pushes about 15kpps at rate of roughly 12% interrupt CPU load. Sometimes when it spikes to 100kpps (rare, but happens), cpu load goes up as high as 30% on interrupts. Now these figures are w/ device polling off. As soon as I turn device polling ON, interrupt load climbs from 12% to 23%. During spikes, it climbs to about 48% to 50%. Any idea why device polling is kind of having... negative impact? Is this b/c I have SMP compiled on a box that really doesn't have two cpu's?? Is SMP+APIC_IO support even required for HTT use? The version btw is FreeBSD 4.9-STABLE. hardware info: Jul 21 23:09:24 r2.bos /kernel: CPU: Intel(R) Xeon(TM) CPU 2.80GHz (2788.16-MHz 686-class CPU) Jul 21 23:09:24 r2.bos /kernel: Origin = "GenuineIntel" Id = 0xf29 Stepping = 9 Jul 21 23:09:25 r2.bos /kernel: em0: <Intel(R) PRO/1000 Network Connection, Version - 1.7.25> port 0xccc0-0xccff mem 0xfcd00000-0xfcd3ffff,0xfcd40000-0xfcd5ffff irq 7 at device 6.0 on pci3 Jul 21 23:09:25 r2.bos /kernel: bge0: <Broadcom BCM5704C Dual Gigabit Ethernet, ASIC rev. 0x2002> mem 0xfcf20000-0xfcf2ffff,0xfcf30000-0xfcf3ffff irq 2 at device 0.0 on pci2 Jul 21 23:09:25 r2.bos /kernel: bge1: <Broadcom BCM5704C Dual Gigabit Ethernet, ASIC rev. 0x2002> mem 0xfcf00000-0xfcf0ffff,0xfcf10000-0xfcf1ffff irq 5 at device 0.1 on pci2 Thanks for any tips! -J -- James Jun TowardEX Technologies, Inc. Technical Lead Network Design, Consulting, IT Outsourcing james@towardex.com Boston-based Colocation & Bandwidth Services cell: 1(978)-394-2867 web: http://www.towardex.com , noc: www.twdx.net
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