Re: Packet drop while using BPF filter
Hi, Have you tried enabling -- /proc/sys/net/core/bpf_jit_enable -- provides JIT compiled BPF on 64 bit linux. * On Wed, Dec 21, 2011 at 12:08:04AM +0530, Mukesh Yadav mukesh@gmail.com wrote: Hi Guys, I am working on user level code which uses BPF filter. Solution has two threads and BPF filter for incoming packets to raw socket dedicated to each thread. Intent is to divide ingress traffic between two thread based on whether dest IP is even or odd. BPF filters used are: Even IP filter :- tcpdump -i interface 'ether dst dest mac ip[19] 0x01 = 0' Odd IP filter :- tcpdump -i interface 'ether dst dest mac ip[19] 0x01 = 1' There is a packet loss for odd IP thread even when CPU is available. Reason being packet drop due recv buffer full. Same amount of traffic is well handled by even IP thread(user code being same in both), scaling CPU to full 100%. In odd IP thread, If filter is changed to tcpdump -i interface 'ether dst dest mac ip proto 17' , all goes fine. Also CPU usage at kernel drops from 50% to 4 % for a particular amount of traffic. Would appreciate any I/ps for reducing load at kernel for packet filtering(Odd/Even IP distribution) Cheers Mukesh ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies -- Raghavendra Prabhu GPG Id : 0xD72BE977 Fingerprint: B93F EBCB 8E05 7039 CD3C A4B8 A616 DCA1 D72B E977 www: wnohang.net ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
Re: Packet drop while using BPF filter
Hi Mukesh On Wed, Dec 21, 2011 at 12:25, Mukesh Yadav mukesh@gmail.com wrote: Thanks Mulyadi, Yeah that a final alternative. Actually I was looking for some optimized way of getting packet filtered at kernel level using BPF filter. You're welcome. Logically, your code should have no problem, but well it seems that the implementation in BPF is not so good somewhere. -- regards, Mulyadi Santosa Freelance Linux trainer and consultant blog: the-hydra.blogspot.com training: mulyaditraining.blogspot.com ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
Packet drop while using BPF filter
Hi Guys, I am working on user level code which uses BPF filter. Solution has two threads and BPF filter for incoming packets to raw socket dedicated to each thread. Intent is to divide ingress traffic between two thread based on whether dest IP is even or odd. BPF filters used are: Even IP filter :- tcpdump -i interface 'ether dst dest mac ip[19] 0x01 = 0' Odd IP filter :- tcpdump -i interface 'ether dst dest mac ip[19] 0x01 = 1' There is a packet loss for odd IP thread even when CPU is available. Reason being packet drop due recv buffer full. Same amount of traffic is well handled by even IP thread(user code being same in both), scaling CPU to full 100%. In odd IP thread, If filter is changed to tcpdump -i interface 'ether dst dest mac ip proto 17' , all goes fine. Also CPU usage at kernel drops from 50% to 4 % for a particular amount of traffic. Would appreciate any I/ps for reducing load at kernel for packet filtering(Odd/Even IP distribution) Cheers Mukesh ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
Re: Packet drop while using BPF filter
Hi Mukesh.. On Wed, Dec 21, 2011 at 01:38, Mukesh Yadav mukesh@gmail.com wrote: BPF filters used are: Even IP filter :- tcpdump -i interface 'ether dst dest mac ip[19] 0x01 = 0' Odd IP filter :- tcpdump -i interface 'ether dst dest mac ip[19] 0x01 = 1' There is a packet loss for odd IP thread even when CPU is available. Reason being packet drop due recv buffer full. Same amount of traffic is well handled by even IP thread(user code being same in both), scaling CPU to full 100%. In odd IP thread, If filter is changed to tcpdump -i interface 'ether dst dest mac ip proto 17' , all goes fine. Also CPU usage at kernel drops from 50% to 4 % for a particular amount of traffic. I have zero experience with BPF, so this is just my theory. In kernel level, (or maybe between kernel and user level), by putting your odd and even filter, kernel work too hard to separate the packets into different queue or channel...or something like that. While in the mean time, incoming packets are bursting This makes buffers filled up fast. How about this... just filter anything that match your target MACfed this up to the user level application and let your application do the odd and even IP filtering? -- regards, Mulyadi Santosa Freelance Linux trainer and consultant blog: the-hydra.blogspot.com training: mulyaditraining.blogspot.com ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
Re: Packet drop while using BPF filter
Thanks Mulyadi, Yeah that a final alternative. Actually I was looking for some optimized way of getting packet filtered at kernel level using BPF filter. On 21 December 2011 06:22, Mulyadi Santosa mulyadi.sant...@gmail.comwrote: Hi Mukesh.. On Wed, Dec 21, 2011 at 01:38, Mukesh Yadav mukesh@gmail.com wrote: BPF filters used are: Even IP filter :- tcpdump -i interface 'ether dst dest mac ip[19] 0x01 = 0' Odd IP filter :- tcpdump -i interface 'ether dst dest mac ip[19] 0x01 = 1' There is a packet loss for odd IP thread even when CPU is available. Reason being packet drop due recv buffer full. Same amount of traffic is well handled by even IP thread(user code being same in both), scaling CPU to full 100%. In odd IP thread, If filter is changed to tcpdump -i interface 'ether dst dest mac ip proto 17' , all goes fine. Also CPU usage at kernel drops from 50% to 4 % for a particular amount of traffic. I have zero experience with BPF, so this is just my theory. In kernel level, (or maybe between kernel and user level), by putting your odd and even filter, kernel work too hard to separate the packets into different queue or channel...or something like that. While in the mean time, incoming packets are bursting This makes buffers filled up fast. How about this... just filter anything that match your target MACfed this up to the user level application and let your application do the odd and even IP filtering? -- regards, Mulyadi Santosa Freelance Linux trainer and consultant blog: the-hydra.blogspot.com training: mulyaditraining.blogspot.com -- Cheers Mukesh Yadav Senior Software Engineer Plot6 Sector 18 Aricent Gurgaon Mob: 9953024169 ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
