Am 20.05.2013 18:01, schrieb Frederic Weisbecker:
> While computing the cputime delta of dynticks CPUs,
> we are mixing up clocks of differents natures:
[...]
> As a consequence, some strange behaviour with unstable tsc
> has been observed such as non progressing constant zero cputime.
> (The 'top' command showing no load).
This happens for example on my trusty ThinkPad X200s (family 6 model 23
stepping 10 Core 2 duo), seriously confusing its user (me :-).
> Fix this by only using local_clock(), or its irq safe/remote
> equivalent, in vtime code.
>
> Reported-by: Mike Galbraith <efa...@gmx.de>
> Suggested-by: Mike Galbraith <efa...@gmx.de>
> Cc: Steven Rostedt <rost...@goodmis.org>
> Cc: Paul E. McKenney <paul...@linux.vnet.ibm.com>
> Cc: Ingo Molnar <mi...@kernel.org>
> Cc: Thomas Gleixner <t...@linutronix.de>
> Cc: Peter Zijlstra <pet...@infradead.org>
> Cc: Borislav Petkov <b...@alien8.de>
> Cc: Li Zhong <zh...@linux.vnet.ibm.com>
> Cc: Mike Galbraith <efa...@gmx.de>
> Signed-off-by: Frederic Weisbecker <fweis...@gmail.com>
FWIW:
Tested-by: Stefan Seyfried <seife+...@b1-systems.com>
This patch fixes the 0% CPU issue on openSUSE Factory kernels for me.
Best regards,
Stefan
--
Stefan Seyfried
Linux Consultant & Developer -- GPG Key: 0x731B665B
B1 Systems GmbH
Osterfeldstraße 7 / 85088 Vohburg / http://www.b1-systems.de
GF: Ralph Dehner / Unternehmenssitz: Vohburg / AG: Ingolstadt,HRB 3537
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