[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

[Xen-devel] Interrupts in Xen: Dynamic-irq and Phys-irq

  • To: Xen-devel@xxxxxxxxxxxxxxxxxxx
  • From: John Que <qwejohn@xxxxxxxxx>
  • Date: Mon, 18 Jul 2005 08:07:24 -0400
  • Delivery-date: Mon, 18 Jul 2005 12:06:04 +0000
  • Domainkey-signature: a=rsa-sha1; q=dns; c=nofws; s=beta; d=gmail.com; h=received:message-id:date:from:reply-to:to:subject:mime-version:content-type:content-transfer-encoding:content-disposition; b=gHpUuAfOXDRjYAKDpbAXmflwzv7USwggYnLRtblCZhEn7ISJlG4iwOV2X0DcFTd+obp4jvpL/HssvUGe2x8eG+9RgG/jQM2o+4zKhJiTZeqcaKgCIS4VEBw6OaB5xOc50tZZjMZkG3PPIih595+1xVO328+5gRDuyybfTQ2/bSI=
  • List-id: Xen developer discussion <xen-devel.lists.xensource.com>

  I am running the xen-unstable (linux 2.6.11 kernel) after building
it from source.

I had noticed that , when starting a new domain, and running:

cat /proc/interrupts, it show many irq which are of type "Dynamic-irq":

for example:
259:        234     Dynamic-irq  blkif

I had traced down it down in xen source  to dynirq_type struct in: 

static struct hw_interrupt_type dynirq_type = 
 I saw a usage of this struct (might it be the only usage ?) 
 in the init_IRQ() method, in this evtchn.c:
 irq_desc[dynirq_to_irq(i)].handler = &dynirq_type; 
 irq_desc is an instance irq_desc struct (in irq.h) ; 
 It's  handler member is a pointer to hw_irq_controller, which is in fact 

 ( in irq.h .there is a "typedef struct hw_interrupt_type  hw_irq_controller");
 Does anybody know and can explain in few sentences what is this Dynamic-irq? 
 What is it's use? 
 The "Dynamic-irq" also appears in Dom0 (for example, when you run 
"cat /proc/interrupts" and look at the  line containing "ctrl-if" or "console").

Besides it, In dom0 there is also "Phys-irq" ; for examples,after 
running "cat /proc/interruupts" in line containing "eth0" or "ide0" or "ide1". 

what is the difference between these 2 types of interrupts ? 

John Q.

Xen-devel mailing list



Lists.xenproject.org is hosted with RackSpace, monitoring our
servers 24x7x365 and backed by RackSpace's Fanatical Support®.