RTEMS pthread performance is GOOD (was Re: Fwd: RTEMS pthreads performance)

[Till Straumann]

MEA CULPA.

Ooops, I'm to blame for a really bad one, sorry.
Obviously, I'm not too experienced with the pthread API :-(

My benchmark code fails to set PTHREAD_EXPLICIT_SCHED and hence
the benchmark task runs at the wrong priority. I had developed the 
pthread stuff for RT-Linux (where EXPLICIT_SCHED is the default,
as it is on some other systems, it seems).

After fixing this, it looks like pthread performance is very similar
to using RTEMS native threads.

An updated version is available at

http://www.slac.stanford.edu/~strauman/rtoslat/index.html

My sincere apologies

-- Till

Joel Sherrill wrote:
> 
> Till Straumann wrote:
> 
>>Joel Sherrill wrote:
>>
>>
>>>Till Straumann wrote:
>>>
>>>
>>>
>>>>Kamen Penev wrote:
>>>>
>>>>
>>>>
>>>>
>>>>>Hi!
>>>>>
>>>>>Looking at your work comparing RTEMS, RTLinux and vxWorks, I am wondering
>>>>>about the unusually poor RTEMS+pthreads result for context switching on a
>>>>>loaded system. Has this been explained (better yet fixed)by the RTEMS
>>>>>development team?
>>>>>
>>>>>
>>>>
>>>Which RTEMS version/target CPU/configuration?
>>>
>>
>>I believe it was ss-20011025 (I can re-run the test later today on a
>>later version).
> 
> 
> That is pretty old and I am 100% positive it predates the work
> I did to improve results on your benchmark.  The ChangeLog entry
> for that is 2002-07-01.
> 
> 
>>The target was a 604 series PowerPC on a Motorola MVME23xx board.
> 
> 
> Do you know what the test is doing?  Is it the same as yours?  Saying
> something is slow doesn't help me much.  RTEMS usually performs
> comparable to VxWorks on benchmarks.  But each time we hit a new
> benchmark comparison, there is new data to optimize against.  
> 
> 
>>-- Till
>>
>>
>>>
>>>
>>>>>Thanks.
>>>>>
>>>>>Kamen Penev
>>>>>Adept Technology
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>
>>>>Good question. I am not using pthreads and the honest answer is "I dont
>>>>know".
>>>>I remember, however having brought this to Joel Sherrill's attention
>>>>(back in 2001
>>>>when I did the tests) and I believe he had some ideas about the cause...
>>>>
>>>>-- Till
>>>>
>>>>
>>>
>>>
>>>
>