It appears that you have two bus types -- PCI-E and PCI-X. em0 - 5 are PCI-E. PCI-E is a spoke-hub (star) bus topology so each em() is on its own bus pathway. One PCI-E device does NOT contend with another.
em6 and em7 are PCI-X and, yes, they're on the same bus, and, yes, they may contend with each other. Are they, (i) a one dual-ports NIC, or (ii) two single-port NICs, or (iii) a chip embedded on the mb? -----Original Message----- From: Mikael Kermorgant <[EMAIL PROTECTED]> Subject: Re: 4.2 and em(4) Date: Tue, 15 Apr 2008 00:46:08 +0200 Hello, I'd like to jump on what you said about separate buses because I haven't looked at this before. You made me curious to understand this dmesg output : cpu0 at mainbus0 pci0 at mainbus0 bus 0: configuration mode 1 (no bios) pchb0 at pci0 dev 0 function 0 "Intel 82Q965 Host" rev 0x02 agp0 at pchb0: aperture at 0xd0000000, size 0x8000000 ppb0 at pci0 dev 1 function 0 "Intel 82Q965 PCIE" rev 0x02: irq 14 pci1 at ppb0 bus 1 ppb1 at pci1 dev 0 function 0 "Intel PCIE-PCIE" rev 0x09 pci2 at ppb1 bus 2 ppb2 at pci1 dev 0 function 2 "Intel PCIE-PCIE" rev 0x09 pci3 at ppb2 bus 3 vga1 at pci0 dev 2 function 0 "Intel 82Q965 Video" rev 0x02 wsdisplay0 at vga1 mux 1: console (80x25, vt100 emulation) wsdisplay0: screen 1-5 added (80x25, vt100 emulation) ppb3 at pci0 dev 28 function 0 "Intel 82801H PCIE" rev 0x02: irq 14 pci4 at ppb3 bus 4 em0 at pci4 dev 0 function 0 "Intel PRO/1000MT (82573L)" rev 0x00: irq 14, address 00:10:f3:10:7e:68 ppb4 at pci0 dev 28 function 1 "Intel 82801H PCIE" rev 0x02: irq 10 pci5 at ppb4 bus 5 em1 at pci5 dev 0 function 0 "Intel PRO/1000MT (82573L)" rev 0x00: irq 10, address 00:10:f3:10:7e:69 ppb5 at pci0 dev 28 function 2 "Intel 82801H PCIE" rev 0x02: irq 11 pci6 at ppb5 bus 6 em2 at pci6 dev 0 function 0 "Intel PRO/1000MT (82573L)" rev 0x00: irq 11, address 00:10:f3:10:7e:6a ppb6 at pci0 dev 28 function 3 "Intel 82801H PCIE" rev 0x02: irq 15 pci7 at ppb6 bus 7 em3 at pci7 dev 0 function 0 "Intel PRO/1000MT (82573L)" rev 0x00: irq 15, address 00:10:f3:10:7e:6b ppb7 at pci0 dev 28 function 4 "Intel 82801H PCIE" rev 0x02: irq 14 pci8 at ppb7 bus 8 em4 at pci8 dev 0 function 0 "Intel PRO/1000MT (82573L)" rev 0x00: irq 14, address 00:10:f3:10:7e:6c ppb8 at pci0 dev 28 function 5 "Intel 82801H PCIE" rev 0x02: irq 10 pci9 at ppb8 bus 9 em5 at pci9 dev 0 function 0 "Intel PRO/1000MT (82573L)" rev 0x00: irq 10, address 00:10:f3:10:7e:6d uhci0 at pci0 dev 29 function 0 "Intel 82801H USB" rev 0x02: irq 5 uhci1 at pci0 dev 29 function 1 "Intel 82801H USB" rev 0x02: irq 15 ehci0 at pci0 dev 29 function 7 "Intel 82801H USB" rev 0x02: irq 5 usb0 at ehci0: USB revision 2.0 uhub0 at usb0 "Intel EHCI root hub" rev 2.00/1.00 addr 1 ppb9 at pci0 dev 30 function 0 "Intel 82801BA Hub-to-PCI" rev 0xf2 pci10 at ppb9 bus 10 em6 at pci10 dev 14 function 0 "Intel PRO/1000MT (82541GI)" rev 0x05: irq 11, address 00:10:f3:10:7e:6e em7 at pci10 dev 15 function 0 "Intel PRO/1000MT (82541GI)" rev 0x05: irq 10, address 00:10:f3:10:7e:6f Just by reading this : ---- pci4 at ppb3 bus 4 em0 at pci4 dev 0 function 0 "Intel PRO/1000MT (82573L)" rev 0x00: irq 14, address 00:10:f3:10:7e:68 ppb4 at pci0 dev 28 function 1 "Intel 82801H PCIE" rev 0x02: irq 10 pci5 at ppb4 bus 5 em1 at pci5 ------ I'd deduce em0 (pci4, bus 4) and em1 (pci5, bus 5) are on separate buses... but am I right ? But em6 and em7 are on the same bus, right ? Thanks in advance, Mikael Kermorgant On Mon, Apr 14, 2008 at 11:14 PM, scott <[EMAIL PROTECTED]> wrote: > We've found the best gateway box -- pf, sshd for "ssh -w" vpn and ipsec > clients, spamd, etc. -- is non-MP, as follows. > > A) Use a box with the fastest memory bandwidth (and latency) your budget > -- cash or time spent scrounging -- can afford/acquire. (e.g. on a > P-III 1 GHz machine, we saw meaningful better top-end results on our > stress tests between using PC133 vs PC100 and again between PC133 CL2.5 > vs CL3 memory sticks.) > > B.1) Server-class motherboards usually have multiple PCI buses (say > again, "buses," not "slots"). Opposing the em(4) nics on separate > buses, with regard to in-to-out flows, helps quite a bit too. e.g > internet --- (em0)(bus1)(pf)(bus2)(em1) --- LAN. > > B.2) Once a while back, we did see some positive affect by trying to > share the driver-IRQ for the like em(4). But not too sure about this > one. > > C) We found, on 4.2, if your mb will play nicely, expressly enabling > ACPI (vs. default APM) functionality seemed to improve the the boxes > throughput too. In our case, INTEL MOTHERBOARDS. Your mb may not like > this, though, so use with care and/or wait to 4.3 release. > > > > -----Original Message----- > From: Stuart Henderson <[EMAIL PROTECTED]> > To: misc@openbsd.org > Subject: Re: 4.2 and em(4) > Date: Mon, 14 Apr 2008 16:23:24 +0000 (UTC) > Mailer: slrn/0.9.8.1 (OpenBSD) > Delivered-To: [EMAIL PROTECTED] > > On 2008-04-14, Joe Warren-Meeks <[EMAIL PROTECTED]> wrote: > > > > If the box was only doing pf stuff, then that would be correct. If you > > were to put a bunch of ftp-proxys on there too, then MP would help, no? > > very little, the bulk data handling is done in kernel by nat/rdr > rules added to the anchors, ftp-proxy only touches the control > connections.
