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Re: next vforkup chapter: lwpctl

On Thu, Feb 17, 2011 at 4:38 PM, Mindaugas Rasiukevicius
<> wrote:
> Garrett Cooper <> wrote:
>> >
>> > But what, that uses LWPCTL, are you actually supposed to be doing after
>> > vfork()?  Whack some environment variables and some globals -- maybe --
>> > then exec*().  What else is legitimate?
>> >
>> > If it doesn't slow down vfork, great, fix whatever.  But vfork
>> > performance really is critical.  Look how much slower, for example,
>> > FreeBSD builds the system than we do.  vfork is a huge part of that.
>> Hi Thor,
>>     Do you have performance metrics to back up your statement below
>> about `FreeBSD build[ing] the system slower than we do' (paraphrased)?
> Note: it uses the same toolchain (i.e. same make, gcc, etc).
> However, I suppose FreeBSD team is aware of these.


    Thanks for the details! I was looking for this (I couldn't find
what Thor was referring to on the lists with a 45 or so minute Google
search; it was turning up a lot of noise about Xen on the mailing
lists :)..).
    It would be interesting to see how well FreeBSD fares now because
7.1 was before the ULE scheduler was setup as the default scheduler. A
lot of work went into making that robust and scalable in 7.2 by
jeffr@, jhb@, kris@, etc; one of the big announcements was made at a
little before 7.0-RELEASE [1] and at MeetBSD 2008 [2] by kris@ when he
was still actively working with the project :/... Things also improved
again with scaling in FreeBSD 8.x, and there's work in the pipeline
for 9.0-RELEASE to get rid of vm-locking which seems to have
qualitatively yielded performance gains on the 2 workstations and 1
server I have FreeBSD CURRENT installed on and actively work with.
    If I can get things up and running like someone did for the NetBSD
slides above with FreeBSD CURRENT and NetBSD CURRENT on my amd64 test
machine (directions welcome :)..), I'll give the tests a shot again to
see how divergent the performance results are between the two BSDs in
this area.


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