timeouts too long bug again...
rizzo at iet.unipi.it
Thu Jan 26 18:50:56 UTC 2012
In sep.2009 i noticed that usleep() select() and friends (including
the in-kernel callouts) would consistently take one tick longer
than they should, and committed a fix to sys/kern/kern_timeout.c
to HEAD and RELENG_8
Now it seems that the bug is there again, in some form:
on 9.0 (and someone reported this also no HEAD) the minimum sleep
interval is now 2 ticks. Callouts seem to be correct (at least,
dummynet delays are exact, and the sysctl
now does not grow at 500 HZ as it did in the past.
Any idea on what might have reintroduced the problem ?
(please spare us the story that usleep gives no guarantees
etc etc - we all know that, but FreeBSD is consistently 1 tick
above the minimum guaranteed interval)
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