From mboxrd@z Thu Jan 1 00:00:00 1970 From: John Que Subject: Interrupts in Xen: Dynamic-irq and Phys-irq Date: Mon, 18 Jul 2005 08:07:24 -0400 Message-ID: Reply-To: John Que Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Return-path: Content-Disposition: inline List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: Xen-devel@lists.xensource.com List-Id: xen-devel@lists.xenproject.org Hello,=20 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:=20 linux-2.6.11-xen-sparse/arch/xen/kernel/evtchn.c: static struct hw_interrupt_type dynirq_type =3D=20 { "Dynamic-irq", startup_dynirq, shutdown_dynirq, enable_dynirq, =09... =09... =09}; =09 I saw a usage of this struct (might it be the only usage ?)=20 in the init_IRQ() method, in this evtchn.c: ...... irq_desc[dynirq_to_irq(i)].handler =3D &dynirq_type;=20 ....... =20 irq_desc is an instance irq_desc struct (in irq.h) ;=20 It's handler member is a pointer to hw_irq_controller, which is in fact= =20 hw_irq_controller. =20 ( in irq.h .there is a "typedef struct hw_interrupt_type hw_irq_controlle= r"); =20 Does anybody know and can explain in few sentences what is this Dynamic-ir= q?=20 What is it's use?=20 =20 The "Dynamic-irq" also appears in Dom0 (for example, when you run=20 "cat /proc/interrupts" and look at the line containing "ctrl-if" or "conso= le"). Besides it, In dom0 there is also "Phys-irq" ; for examples,after=20 running "cat /proc/interruupts" in line containing "eth0" or "ide0" or "ide= 1".=20 what is the difference between these 2 types of interrupts ?=20 Regards, John Q.