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| author | YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org> | 2005-10-30 01:15:42 (GMT) |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2005-10-30 04:40:35 (GMT) |
| commit | 4b8f573b5db02a3017afbba49026a6aef480174f (patch) | |
| tree | 4abf19125526809d4be44cb83373f85605854575 | |
| parent | 930fc45a49ddebe7555cc5c837d82b9c27e65ff4 (diff) | |
| download | linux-4b8f573b5db02a3017afbba49026a6aef480174f.tar.xz | |
[PATCH] TIMERS: add missing compensation for HZ == 250
Add missing compensation for (HZ == 250) != (1 << SHIFT_HZ) in
second_overflow().
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
| -rw-r--r-- | kernel/timer.c | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/kernel/timer.c b/kernel/timer.c index 3ba10fa..6a2e5f8 100644 --- a/kernel/timer.c +++ b/kernel/timer.c @@ -752,6 +752,15 @@ static void second_overflow(void) else time_adj += (time_adj >> 2) + (time_adj >> 5); #endif +#if HZ == 250 + /* Compensate for (HZ==250) != (1 << SHIFT_HZ). + * Add 1.5625% and 0.78125% to get 255.85938; => only 0.05% error (p. 14) + */ + if (time_adj < 0) + time_adj -= (-time_adj >> 6) + (-time_adj >> 7); + else + time_adj += (time_adj >> 6) + (time_adj >> 7); +#endif #if HZ == 1000 /* Compensate for (HZ==1000) != (1 << SHIFT_HZ). * Add 1.5625% and 0.78125% to get 1023.4375; => only 0.05% error (p. 14) |