Messages in this thread | | | Date | Sat, 10 Mar 2001 02:03:03 -0800 | From | george anzinger <> | Subject | Re: nanosleep question |
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Michael Reinelt wrote: > > george anzinger wrote: > > > > Michael Reinelt wrote: > > > > > > At the moment I implemented by own delay loop using a small assembler > > > loop similar to the one used in the kernel. This has two disadvantages: > > > assembler isn't that portable, and the loop has to be calibrated. > > > > Why not use C? As long as you calibrate it, it should do just fine. > Because the compiler might optimize it away.
Not if you use volatile on the data type. > > > On > > the other hand, since you are looping anyway, why not loop on a system > > time of day call and have the loop exit when you have the required time > > in hand. These calls have microsecond resolution. > I'm afraid they don't (at least with kernel 2.0, I didn't try this with > 2.4).
Gosh, I started with 2.2.14 and it does full microsecond resolution.
They have microsecond resolution, but increment only every 1/HZ. > > Someone gave me a hint to loop on rdtsc. I will look into this.
This ticks at 1/"cpu MHz", which can be found by: "cat /proc/cpuinfo" > > > > - why are small delays only possible up to 2 msec? what if I needed a > > > delay of say 5msec? I can't get it? > > > > If you want other times, you can always make more than one call to > > nanosleep. > Good point!
~snip~
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