WARNING - OLD ARCHIVES

This is an archived copy of the Xen.org mailing list, which we have preserved to ensure that existing links to archives are not broken. The live archive, which contains the latest emails, can be found at http://lists.xen.org/
   
 
 
Xen 
 
Home Products Support Community News
 
   
 

xen-devel

RE: [Xen-devel] Re: [PATCH] add long interrupt measurement capability

To: Dulloor <dulloor@xxxxxxxxx>, Keir Fraser <keir.fraser@xxxxxxxxxxxxx>
Subject: RE: [Xen-devel] Re: [PATCH] add long interrupt measurement capability
From: "Tian, Kevin" <kevin.tian@xxxxxxxxx>
Date: Mon, 11 May 2009 12:50:52 +0800
Accept-language: en-US
Acceptlanguage: en-US
Cc: Ian Pratt <Ian.Pratt@xxxxxxxxxxxxx>, "Xen-Devel \(E-mail\)" <xen-devel@xxxxxxxxxxxxxxxxxxx>, Dan Magenheimer <dan.magenheimer@xxxxxxxxxx>
Delivery-date: Sun, 10 May 2009 21:52:21 -0700
Envelope-to: www-data@xxxxxxxxxxxxxxxxxxx
In-reply-to: <940bcfd20905090212p42496b38x667a393ffddaaf39@xxxxxxxxxxxxxx>
List-help: <mailto:xen-devel-request@lists.xensource.com?subject=help>
List-id: Xen developer discussion <xen-devel.lists.xensource.com>
List-post: <mailto:xen-devel@lists.xensource.com>
List-subscribe: <http://lists.xensource.com/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=subscribe>
List-unsubscribe: <http://lists.xensource.com/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=unsubscribe>
References: <4FA716B1526C7C4DB0375C6DADBC4EA3417372CDD1@xxxxxxxxxxxxxxxxxxxxxxxxx> <C62AF5A5.A80D%keir.fraser@xxxxxxxxxxxxx> <940bcfd20905090212p42496b38x667a393ffddaaf39@xxxxxxxxxxxxxx>
Sender: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
Thread-index: AcnQhlAdfgd5GDM9T7mPfUwsGgMniQBbTXDA
Thread-topic: [Xen-devel] Re: [PATCH] add long interrupt measurement capability
I guess you can handle it much simpler by stamping a record in both irq_enter and irq_exit. All the statistics jobs are left for xentrace script to digest.
 
Also I'd call it as trace_irq instead of trace_guest_irq. :-)
 
Thanks,
Kevin


From: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx [mailto:xen-devel-bounces@xxxxxxxxxxxxxxxxxxx] On Behalf Of Dulloor
Sent: 2009年5月9日 17:12
To: Keir Fraser
Cc: Ian Pratt; Xen-Devel (E-mail); Dan Magenheimer
Subject: Re: [Xen-devel] Re: [PATCH] add long interrupt measurement capability

Here is a xentrace patch.

- Should irq_desc_measure_t move to some .h file ?
- I have defined the new trace event in general class. Is it fine ?

- I have defined tsc_in as volatile to avoid initializing it in the main code path.

thanks
dulloor

On Sat, May 9, 2009 at 3:56 AM, Keir Fraser <keir.fraser@xxxxxxxxxxxxx> wrote:
On 08/05/2009 22:53, "Ian Pratt" <Ian.Pratt@xxxxxxxxxxxxx> wrote:

>> Perhaps.  However measuring cycles is important and, more
>> specifically, measuring MAX cycles spent across a set of
>> interrupts.  As a result, I suspect any code that measures
>> this (regardless of whether the result is reported by
>> xentrace or debug-key) would likely encounter the
>> same objection from Keir.
>
> I can't imagine there'd be any objection to adding trace macros to record
> this. The xentrace log processing tool can then be updated to generate max or
> histogram values.

Yes, xentrace records would be okay. It's adding another debug key and
printing to Xen console for this purpose which I do not think is worthwhile.

 -- Keir



_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel