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[PATCH] ppc64: fix initialisation of gettimeofday calculations

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On PPC64, we keep track of when we need to update jiffies (and the
variables used to calculate the time of day) based on the time base.

If the time base frequence is sufficiently high compared to the
processor clock frequency, then it is possible for the time of day
variables to be corrupted at the time of the first decrementer interrupt
we take.  This became obvious on a legacy iSeries where the time base
frequency is the same as the processor clock.

This one line patch fixes the initialisation so that the time of day
variables and the indicator we use to tell when updates are due are
better synchronised.

Signed-off-by:  Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Stephen Rothwell 2005-05-25 13:41:26 +10:00 committed by Linus Torvalds
parent 2a24ab628a
commit 8f80e5c911
1 changed files with 1 additions and 0 deletions
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arch/ppc64/kernel/time.c
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@ -515,6 +515,7 @@ void __init time_init(void)
do_gtod.varp = &do_gtod.vars[0];
do_gtod.var_idx = 0;
do_gtod.varp->tb_orig_stamp = tb_last_stamp;
get_paca()->next_jiffy_update_tb = tb_last_stamp + tb_ticks_per_jiffy;
do_gtod.varp->stamp_xsec = xtime.tv_sec * XSEC_PER_SEC;
do_gtod.tb_ticks_per_sec = tb_ticks_per_sec;
do_gtod.varp->tb_to_xs = tb_to_xs;