diff options
author | Bob Picco <bob.picco@hp.com> | 2007-07-18 18:51:28 -0400 |
---|---|---|
committer | Tony Luck <tony.luck@intel.com> | 2007-07-20 14:23:02 -0400 |
commit | 1f564ad6d4182859612cbae452122e5eb2d62a76 (patch) | |
tree | ef98ce12ed64853437c35a81e29f0d1c09a4393b /Documentation | |
parent | 0aa366f351d044703e25c8425e508170e80d83b1 (diff) |
[IA64] remove time interpolator
Remove time_interpolator code (This is generic code, but
only user was ia64. It has been superseded by the
CONFIG_GENERIC_TIME code).
Signed-off-by: Bob Picco <bob.picco@hp.com>
Signed-off-by: John Stultz <johnstul@us.ibm.com>
Signed-off-by: Peter Keilty <peter.keilty@hp.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Diffstat (limited to 'Documentation')
-rw-r--r-- | Documentation/time_interpolators.txt | 41 |
1 files changed, 0 insertions, 41 deletions
diff --git a/Documentation/time_interpolators.txt b/Documentation/time_interpolators.txt deleted file mode 100644 index e3b60854fbc2..000000000000 --- a/Documentation/time_interpolators.txt +++ /dev/null | |||
@@ -1,41 +0,0 @@ | |||
1 | Time Interpolators | ||
2 | ------------------ | ||
3 | |||
4 | Time interpolators are a base of time calculation between timer ticks and | ||
5 | allow an accurate determination of time down to the accuracy of the time | ||
6 | source in nanoseconds. | ||
7 | |||
8 | The architecture specific code typically provides gettimeofday and | ||
9 | settimeofday under Linux. The time interpolator provides both if an arch | ||
10 | defines CONFIG_TIME_INTERPOLATION. The arch still must set up timer tick | ||
11 | operations and call the necessary functions to advance the clock. | ||
12 | |||
13 | With the time interpolator a standardized interface exists for time | ||
14 | interpolation between ticks. The provided logic is highly scalable | ||
15 | and has been tested in SMP situations of up to 512 CPUs. | ||
16 | |||
17 | If CONFIG_TIME_INTERPOLATION is defined then the architecture specific code | ||
18 | (or the device drivers - like HPET) may register time interpolators. | ||
19 | These are typically defined in the following way: | ||
20 | |||
21 | static struct time_interpolator my_interpolator { | ||
22 | .frequency = MY_FREQUENCY, | ||
23 | .source = TIME_SOURCE_MMIO32, | ||
24 | .shift = 8, /* scaling for higher accuracy */ | ||
25 | .drift = -1, /* Unknown drift */ | ||
26 | .jitter = 0 /* time source is stable */ | ||
27 | }; | ||
28 | |||
29 | void time_init(void) | ||
30 | { | ||
31 | .... | ||
32 | /* Initialization of the timer *. | ||
33 | my_interpolator.address = &my_timer; | ||
34 | register_time_interpolator(&my_interpolator); | ||
35 | .... | ||
36 | } | ||
37 | |||
38 | For more details see include/linux/timex.h and kernel/timer.c. | ||
39 | |||
40 | Christoph Lameter <christoph@lameter.com>, October 31, 2004 | ||
41 | |||