linux-kernel - High read_hpet overhead of perf

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Date:	Tue, 06 Oct 2009 21:40:38 +0200
From:	Simon Holm Thøgersen <odie@...aau.dk>
To:	linux-kernel@...r.kernel.org
Subject: High read_hpet overhead of perf

Whenever I run 'perf top' I get read_hpet in the top two of most used
functions, e.g. running it during an active iperf session gives me
something like the following

	39215.00 - 19.5% : read_hpet
	22505.00 - 11.2% : copy_user_generic_string

Could that be related to the following from my dmesg?
Marking TSC unstable due to TSC halts in idle

My processor is an Intel(R) Core(TM)2 Duo CPU P8600.

Or is it perhaps something completely else?

Simon Holm Thøgersen

View attachment ".config" of type "text/x-mpsub" (65927 bytes)

View attachment "dmesg-high-read-hpet-overhead" of type "text/plain" (49190 bytes)