lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
Open Source and information security mailing list archives
| ||
|
Message-ID: <4BF056F0.8010008@ans.pl> Date: Sun, 16 May 2010 22:34:56 +0200 From: Krzysztof Olędzki <ole@....pl> To: Eric Dumazet <eric.dumazet@...il.com> CC: Michael Chan <mchan@...adcom.com>, "netdev@...r.kernel.org" <netdev@...r.kernel.org> Subject: Re: bnx2/BCM5709: why 5 interrupts on a 4 core system (2.6.33.3) On 2010-05-16 22:15, Eric Dumazet wrote: > Le dimanche 16 mai 2010 à 13:00 -0700, Michael Chan a écrit : >> Krzysztof Oledzki wrote: >> >>> On 2010-05-16 20:51, Michael Chan wrote: >>>> Krzysztof Oledzki wrote: >>>> >>>>> >>>>> Why the driver registers 5 interrupts instead of 4? How to >>>>> limit it to 4? >>>>> >>>> >>>> The first vector (eth0-0) handles link interrupt and other slow >>>> path events. It also has an RX ring for non-IP packets that are >>>> not hashed by the RSS hash. The majority of the rx packets should >>>> be hashed to the rx rings eth0-1 - eth0-4, so I would assign these >>>> vectors to different CPUs. >>> >>> Thank you for your prompt response. >>> >>> In my case the first vector must be handling something more: >>> - "ping -f 192.168.0.1" increases interrupts on both eth1-0 >>> and eth1-4 >>> - "ping -f 192.168.0.2" increases interrupts on both eth1-0 >>> and eth1-3 >>> - "ping -f 192.168.0.3" increases interrupts on both eth1-0 >>> and eth1-1 >>> - "ping -f 192.168.0.7" increases interrupts on both eth1-0 >>> and eth1-2 >>> >>> CPU0 CPU1 CPU2 CPU3 >>> 67: 1563979 0 0 0 >>> PCI-MSI-edge eth1-0 >>> 68: 1072869 0 0 0 >>> PCI-MSI-edge eth1-1 >>> 69: 137905 0 0 0 >>> PCI-MSI-edge eth1-2 >>> 70: 259246 0 0 0 >>> PCI-MSI-edge eth1-3 >>> 71: 760252 0 0 0 >>> PCI-MSI-edge eth1-4 >>> >>> As you can see, eth1-1 + eth1-2 + eth1-3 + eth1-4 ~= eth1-0. >> >> I think that ICMP ping packets will always go to ring 0 (eth1-0) >> because they are non-IP packets. I need to double check tomorrow >> on how exactly the hashing works on RX. Can you try running IP >> traffic? IP packets should theoretically go to rings 1 - 4. >> > > ICMP packets are IP packets (Protocol=1) Exactly. However, the firmware may handle ICMP and TCP in a different way. >>> So, it seems that TX or RX is always handled by the first vector. >>> I'll try to find if it is TX or RX. >>> >>> BTW: I'm using .1Q vlans over bonding, does it change anything? >> >> That should not matter, as the VLAN tag is stripped before hashing. > > warning, bonding currently is not multiqueue aware. > > All tx packets through bonding will use txqueue 0, since bnx2 doesnt > provide a ndo_select_queue() function. OK, that explains everything. Thank you Eric. I assume it may take some time for bonding to become multiqueue aware and/or bnx2x to provide ndo_select_queue? BTW: With a normal router workload, should I expect big performance drop when receiving and forwarding the same packet using different CPUs? Bonding provides very important functionality, I'm not able to drop it. :( Best regards, Krzysztof Olędzki -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Powered by blists - more mailing lists