linux-kernel - Re: [PATCH 0/26] oprofile: Performance counter multiplexing

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Message-ID: <87ljm8hcjx.fsf@basil.nowhere.org>
Date:	Tue, 28 Jul 2009 20:45:06 +0200
From:	Andi Kleen <andi@...stfloor.org>
To:	Robert Richter <robert.richter@....com>
Cc:	Ingo Molnar <mingo@...e.hu>, LKML <linux-kernel@...r.kernel.org>,
	oprofile-list <oprofile-list@...ts.sourceforge.net>
Subject: Re: [PATCH 0/26] oprofile: Performance counter multiplexing

Robert Richter <robert.richter@....com> writes:
>  	  If unsure, say N.
>  
> +config OPROFILE_EVENT_MULTIPLEX
> +	bool "OProfile multiplexing support (EXPERIMENTAL)"
> +	default n
> +	depends on OPROFILE && X86
> +	help
> +	  The number of hardware counters is limited. The multiplexing
> +	  feature enables OProfile to gather more events than counters
> +	  are provided by the hardware. This is realized by switching
> +	  between events at an user specified time interval.
> +

I would suggest to drop that CONFIG and have the code unconditional.
It's not a lot code and should be always available.

Will do more detailed review later and will look at Intel P6 support.

Where's the userland support for this?

-Andi

-- 
ak@...ux.intel.com -- Speaking for myself only.
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