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

To:	Keir Fraser <keir.fraser@xxxxxxxxxxxxx>
Subject:	Re: [Xen-devel] Re: [PATCH] add long interrupt measurement capability
From:	Dulloor <dulloor@xxxxxxxxx>
Date:	Sat, 9 May 2009 05:12:14 -0400
Cc:	Ian Pratt <Ian.Pratt@xxxxxxxxxxxxx>, "Xen-Devel \(E-mail\)" <xen-devel@xxxxxxxxxxxxxxxxxxx>, Dan Magenheimer <dan.magenheimer@xxxxxxxxxx>
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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

measure_irq.patch
Description: Text Data

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