Re: Failed to hand off onionskin

[Scott Bennett <bennett@xxxxxxxxxx>]

     On Sat, 20 Dec 2008 03:25:33 +0100 Mitar <mmitar@xxxxxxxxx> wrote:
>On Sat, Dec 20, 2008 at 12:45 AM, Scott Bennett <bennett@xxxxxxxxxx> wrote:
>> That is odd.  In my experience, tor has 4 + NumCPUs threads, except
>> right after a SIGHUP or during initialization.  I normally only see two
>> threads do any work, and most of it is done by one of those two.  Although
>> I run it on a P4 Prescott, it is HT-enabled, so I set NumCPUs 2.  Most
>> likely, the onionskin-decoding threads are used so infrequently that I only
>> see one in use at a time anyway.
>
>I am using FreeBSD. And if I set NumCPUs to 1, then I have 2 threads
>reported by top, if I set NumCPUs to 3, then I have 3 threads reported
>by top.

     I am running FreeBSD ~6.3 (i386), but I see the thread counts stated
earlier when running it as a relay.  In client-only mode, I think there's
only one or two threads.
>
>> Are you seeing any significant paging activity on that system?  If not,
>> then I doubt that is the problem.
>
>No. And I was not thinking that paging/swaping is a problem. But it is
>5 MB/s of data to be processed what could be a problem if it is has to
>be copied a lot around in the memory (RAM).

     Well, if the VM system isn't working hard, then the CPU speed would
be the main thing involved in lots of copying.
>
>> Even small amounts of paging activity are not likely a problem.  Is that
>> machine dedicated to tor?  Or is it also running other jobs with large
>> (relative to the real memory of the machine) memory requirements?
>
>It is not dedicated to Tor but at the moment I am testing it only with
>Tor. So currently it does not have much other load, not CPU nor
>memory. But later on (when I will tweak it correctly) it will have
>also some other things running.
>
     It should be okay to let tor run at full capacity then.  FreeBSD's
scheduler should keep less demanding processes serviced better than tor
if tor is having the high CPU usage you mentioned before.  Reducing the
maximum data rates in torrc is intended to be used to leave some data
transmission/reception rate capacity unused by tor, so that it can be
used by other procdesses.


                                  Scott Bennett, Comm. ASMELG, CFIAG
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