>> That's looks like a lot of CPU consumption, which I would like to avoid
>> because time_to_sleep is nondeterministic in my case.
>
> If you want to delay for less than a tick, you pretty much need to busy-wait.
> There's no way to set a timer for intervals less than a tick in the regular
> kerne
Hello,
>> > You can spin on the gettimeofday() result in userspace.
>> How can I use it?
> Something like:
>
> gettimeofday(&curtime,0);
> add_usecs(&curtime, time_to_sleep);
> do {
> gettimeofday(&curtime,0);
> } while (time_before(&curtime, &expiry);
That's looks like a lot of CPU consum
Actually look at linux/Documentation/rtc.txt for a "reasonably portable" way to
get
very small quanta with fair regularity.
Since the original poster wanted it to be user accessible, and since it is a
contended/exclusive device, he may want to make a broker daemon or something.
Since nanosleep d
Jan Engelhardt wrote:
You can spin on the gettimeofday() result in userspace.
How can I use it?
Something like:
gettimeofday(&curtime,0);
add_usecs(&curtime, time_to_sleep);
do {
gettimeofday(&curtime,0);
} while (time_before(&curtime, &expiry);
Of course, if someone changes the system ti
>Running your program here I see even worse values than that on 2.6.11-mm4
>and it's also interresting to see that for a lot of continuous runs the
>values reported drop steadily and eventually settle around ~1100, but if I
>insert a sleep 1 between runs, then I see a steady ~1000 reported.
>T
Jan Engelhardt <[EMAIL PROTECTED]> wrote:
>
> I have found that FreeBSD has a very good precision of small sleeps --
Linux nanosleep() used to have a busywait loop for sleeps less than two
milliseconds. 2.4.x still does.
We thought it was stupid and took it out.
> what's holding Linux back fro
On Sun, 20 Mar 2005, Jan Engelhardt wrote:
> Hello,
>
>
> I have found that FreeBSD has a very good precision of small sleeps --
> what's holding Linux back from doing the same? Using the code snippet below,
> FBSD yields between 2 and 80 us on the average while Linux is at
> "constantly" ~100
Hello,
I have found that FreeBSD has a very good precision of small sleeps --
what's holding Linux back from doing the same? Using the code snippet below,
FBSD yields between 2 and 80 us on the average while Linux is at
"constantly" ~100 (with HZ=1000) and ~1000 (HZ=100).
Jan Engelhardt
--
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