Re: 2.6.27/2.6.28: irqbalance dies shortly after starting the daemonon x86 but not x86_64, why?

From: Justin Piszcz
Date: Fri Jan 02 2009 - 20:11:19 EST




On Fri, 2 Jan 2009, Kyle McMartin wrote:

On Fri, Jan 02, 2009 at 07:32:21PM -0500, Justin Piszcz wrote:
The CPU = E6700 so yep, so if there is one physical socket with 4 cores it
keeps? For it to keep and not oneshot you need > 2 cores?


It depends... if your 4-core is laid out with four cores sharing one
external cache, then it will terminate, if, say you had 4 cores with
each pair sharing a cache (so two external caches) then it would
continue as a daemon. (If you had 2 sockets with a processor in each
one, it would continue running as well no matter how many cores on
each.)

If you run irqbalance --debug, it will show you the topology it detects.
If you have multiple cache domains, and it is still exiting, then we
have a bug. :)

cheers, Kyle


Looks correct, just a single cache domain on this host-- thanks.

# irqbalance --debug
Package 0: cpu mask is 00000003 (workload 0)
Cache domain 0: cpu mask is 00000003 (workload 0)
CPU number 0 (workload 0)
CPU number 1 (workload 0)
Interrupt 315 (class ethernet) has workload 20 Interrupt 0 (class timer) has workload 0 Interrupt 314 (class storage) has workload 11 Interrupt 16 (class legacy) has workload 216 Interrupt 17 (class legacy) has workload 122 Interrupt 23 (class legacy) has workload 26 Interrupt 19 (class legacy) has workload 18 Interrupt 1 (class legacy) has workload 1 Interrupt 18 (class legacy) has workload 0 Interrupt 9 (class legacy) has workload 0 Interrupt 6 (class legacy) has workload 0



-----------------------------------------------------------------------------
IRQ delta is 3963 Package 0: cpu mask is 00000003 (workload 2474)
Cache domain 0: cpu mask is 00000003 (workload 2474)
CPU number 0 (workload 1343)
Interrupt 314 (storage/13)
Interrupt 16 (legacy/1080)
Interrupt 19 (legacy/245)
Interrupt 18 (legacy/0)
Interrupt 6 (legacy/0)
CPU number 1 (workload 1131)
Interrupt 315 (ethernet/132)
Interrupt 17 (legacy/689)
Interrupt 23 (legacy/291)
Interrupt 1 (legacy/14)
Interrupt 9 (legacy/0)


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