SCHED_ULE / NetGraph interaction broken somwhere between r227874
avg at FreeBSD.org
Thu Jan 12 10:30:02 UTC 2012
on 12/01/2012 12:05 Lev Serebryakov said the following:
> Hello, Andriy.
> You wrote 12 января 2012 г., 13:54:41:
>>> Switching to 4BSD helps. 4BSD works as usual: all CPU time is
>>> interrupts and network thread, system is responsive under heaviest load,
>>> normal operations of DNS, DHCP and hostapd.
>> How reproducible is this result?
>> In other words, have you definitely ruled out all other factors besides the
> I have two almost-identical NanoBSD images which differs in one line in kernel
> config -- option about scheduler. Worlds are exactly the same, only kernels were
> Alexander Motin suggests, that switching scheduler could slightly
> change stack consumption, which triggers switching to ng_queue
> instead of direct calls.
> Really, here is diff between "md5" of all files of one and other
Well, I mostly meant things like uptime, load level and pattern, etc.
But what mav says makes sense.
Also I remember seeing some very old reports about some strange issues with
SCHED_ULE and dummynet.
Some links that I found:
Given the last link, I wonder if binding the ng_queue thread to a particular CPU
would change anything.
> blob# diff ~lev/bsd-image.md5sums ~lev/ule-image.md5sums
> < MD5 (./boot/kernel/kernel) = 3bb0dd757628b5065d27ee5e7fc22eb3
>> MD5 (./boot/kernel/kernel) = 5ba379d2c73e1277566f4bbcb618a9f2
> < MD5 (./conf/base/var/log/userlog) = a827af82c1f780687706b19c7d94b29e
>> MD5 (./conf/base/var/log/userlog) = fc289b66ae6cb23f9b24b694bf12157b
> < MD5 (./var/log/userlog) = a827af82c1f780687706b19c7d94b29e
>> MD5 (./var/log/userlog) = fc289b66ae6cb23f9b24b694bf12157b
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