perf_counter: x86: More accurate counter update

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Take the counter width into account instead of assuming 32 bits.

In particular Nehalem has 44 bit wide counters, and all
arithmetics should happen on a 44-bit signed integer basis.

[ Impact: fix rare event imprecision, warning message on Nehalem ]

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

...

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Peter Zijlstra 2009-05-13 09:45:19 +02:00 • committed by Ingo Molnar

parent 1a853e3687

commit ec3232bdf8

1 changed files with 6 additions and 3 deletions

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arch/x86/kernel/cpu/perf_counter.c

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