Messages in this thread | ![/](/images/icornerl.gif) | | From | Roger Larsson <> | Subject | Re: Linux-Kernel Archive: No 100 HZ timer ! | Date | Sun, 15 Apr 2001 04:10:34 +0200 |
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On Thursday 12 April 2001 23:52, Andre Hedrick wrote: > Okay but what will be used for a base for hardware that has critical > timing issues due to the rules of the hardware? > > I do not care but your drives/floppy/tapes/cdroms/cdrws do: > > /* > * Timeouts for various operations: > */ > #define WAIT_DRQ (5*HZ/100) /* 50msec - spec allows up to 20ms > */ #ifdef CONFIG_APM > #define WAIT_READY (5*HZ) /* 5sec - some laptops are very > slow */ #else > #define WAIT_READY (3*HZ/100) /* 30msec - should be instantaneous > */ #endif /* CONFIG_APM */ > #define WAIT_PIDENTIFY (10*HZ) /* 10sec - should be less than 3ms (?), if > all ATAPI CD is closed at boot */ #define WAIT_WORSTCASE (30*HZ) /* 30sec > - worst case when spinning up */ #define WAIT_CMD (10*HZ) /* 10sec > - maximum wait for an IRQ to happen */ #define WAIT_MIN_SLEEP (2*HZ/100) > /* 20msec - minimum sleep time */ > > Give me something for HZ or a rule for getting a known base so I can have > your storage work and not corrupt. >
Wouldn't it make sense to define these in real world units? And to use that to determine requested accuracy...
Those who wait for seconds will probably not have a problem with up to (half) a second longer wait - or...? Those in range of the current jiffie should be able to handle up to one jiffie longer...
Requesting a wait in ms gives yo ms accuracy...
/RogerL
-- Roger Larsson Skellefteå Sweden - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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