Date: Fri, 23 Aug 2013 17:23:51 +0400 From: Dmitry Sivachenko <trtrmitya@gmail.com> To: hackers@freebsd.org Subject: About CPU cores numbering an processor affinity Message-ID: <1D21F5BC-63CD-4B33-9286-6687E62FDB15@gmail.com>
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Hello!
I am using FreeBSD-9-STABLE on the following hardware:
FreeBSD/SMP: Multiprocessor System Detected: 24 CPUs
FreeBSD/SMP: 2 package(s) x 6 core(s) x 2 SMT threads
So I have 2 physical CPUs with 6 core each.
# cpuset -g
pid -1 mask: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, =
17, 18, 19, 20, 21, 22, 23
So each of 24 cores are numbered 0..23.
1) In what particular order are these cores numbered? Can I assume that =
0..11 correspond to 1st physical CPU and 12..23 to second? How SMT =
threads are numbered within each core?
2) This machine has Intel network adapter (em driver). I want to pin =
network interrupt thread and proxy software to the same processor so =
they share at least L2 or L3 cache. How can I do this? =46rom the one =
hand, I see the following processes:
11 root -92 - 0K 720K WAIT 19 146:38 0.00% =
intr{irq260: em1:rx 0}
11 root -92 - 0K 720K WAIT 19 15:11 0.00% =
intr{irq261: em1:tx 0}
=46rom the other hand, the following processes seems to be unrelated to =
network but they share same PID:
11 root -60 - 0K 720K WAIT 1 131:20 0.00% =
intr{swi4: clock}
11 root -88 - 0K 720K WAIT 17 40:03 0.00% =
intr{irq263: ahci0}
11 root -72 - 0K 720K WAIT 22 17:35 0.00% =
intr{swi1: netisr 0}
11 root -88 - 0K 720K WAIT 3 3:08 0.00% =
intr{irq256: mfi0}
Should I use "-x" option of cpuset for that purpose (to bind irq 260 and =
261 in my example)?
Thanks in advance!
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