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From: schwidefsky@de.ibm.com
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To: Andi Kleen <ak@suse.de>
cc: Alan Cox <alan@lxorguk.ukuu.org.uk>, Andi Kleen <ak@suse.de>,
        Mark Salisbury <mbs@mc.com>, Jeff Dike <jdike@karaya.com>,
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Message-ID: <C1256A2A.0046E317.00@d12mta07.de.ibm.com>
Date: Tue, 10 Apr 2001 14:54:31 +0200
Subject: Re: No 100 HZ timer !
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>Does not sound very attractive all at all on non virtual machines (I see
the point on
>UML/VM):
>making system entry/context switch/interrupts slower, making add_timer
slower, just to
>process a few less timer interrupts. That's like robbing the fast paths
for a slow path.
The system entry/exit/context switch is slower. The add_timer/mod_timer is
only
a little bit slower in the case a new soonest timer event has been created.
 I
think you can forget the additional overhead for add_timer/mod_timer, its
the
additional path length on the system entry/exit that might be problematic.

blue skies,
   Martin

Linux/390 Design & Development, IBM Deutschland Entwicklung GmbH
Sch?naicherstr. 220, D-71032 B?blingen, Telefon: 49 - (0)7031 - 16-2247
E-Mail: schwidefsky@de.ibm.com


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