Snort mailing list archives
Re: Question about CPU affinity for interrupts
From: Livio Ricciulli <livio () metaflows com>
Date: Tue, 11 Mar 2014 09:57:11 -0700
The driver usually copies the packets from the NIC to the memory of the node (or hardware thread) where the IRQ' affinity is mapped.
If you do numactl --hardware You will see your memory architecture.I am guessing all nodes use the same memory in your case; if so, I would map the IRQ to the free CPUs. If not, see below:
If your NIC driver/chipset can do symmetric RSS, then you would want to map each interrupt to a node with the smallest distance to the node where Snort will consume the packets from that IRQ. If your NIC cannot do RSS, it does not matter since the packets from each interrupt will be consumed by all Snort processes.
Livio. On 03/10/2014 07:38 PM, Roger Campbell wrote:
Hi everyone, had a question about IRQs and PF_RING.Currently I'm testing out PF_RING and snort 2.9.6 on a 1Gb/s link that usually tops out around 800Mb/s. The system has 16 physical cores (32 Hyper-Threads).If I run 8 snort instances in the format below, load is handled pretty well.snort -R 1 --daq-dir=/usr/local/lib/daq --daq pfring --daq-mode passive --daq-var clusterid=10 --daq-var bindcpu=4 -c /IDS/snort/etc/snort.conf -l /IDS/snort/log1 -u snort -g snort -i eth4 -D snort -R 2 --daq-dir=/usr/local/lib/daq --daq pfring --daq-mode passive --daq-var clusterid=10 --daq-var bindcpu=6 -c /IDS/snort/etc/snort.conf -l /IDS/snort/log2 -u snort -g snort -i eth4 -D(continues using CPU 8,10,12,14,16,18)I know that I should set CPU affinity for interrupts for each rx queue to a specific CPU or set of CPUs. My question is, should I bind these to 8 free cores, or should I bind them to cores which are already hosting a snort process?All of the IRQs are currently being processed by ksoftirqd/0 on CPU 0 which is not optimal.------------------------------------------------------------------------------ Learn Graph Databases - Download FREE O'Reilly Book "Graph Databases" is the definitive new guide to graph databases and their applications. Written by three acclaimed leaders in the field, this first edition is now available. Download your free book today! http://p.sf.net/sfu/13534_NeoTech _______________________________________________ Snort-users mailing list Snort-users () lists sourceforge net Go to this URL to change user options or unsubscribe: https://lists.sourceforge.net/lists/listinfo/snort-users Snort-users list archive: http://sourceforge.net/mailarchive/forum.php?forum_name=snort-users Please visit http://blog.snort.org to stay current on all the latest Snort news!
------------------------------------------------------------------------------ Learn Graph Databases - Download FREE O'Reilly Book "Graph Databases" is the definitive new guide to graph databases and their applications. Written by three acclaimed leaders in the field, this first edition is now available. Download your free book today! http://p.sf.net/sfu/13534_NeoTech
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Current thread:
- Question about CPU affinity for interrupts Roger Campbell (Mar 10)
- Re: Question about CPU affinity for interrupts Livio Ricciulli (Mar 11)
- Re: Question about CPU affinity for interrupts Roger Campbell (Mar 11)
- Re: Question about CPU affinity for interrupts Livio Ricciulli (Mar 11)
- Re: Question about CPU affinity for interrupts Roger Campbell (Mar 11)
- Re: Question about CPU affinity for interrupts Livio Ricciulli (Mar 11)