Hallo Chris,

is there a reason, that you have chosen 5140 byte buffer instead
of 5120 like Solaris has chosen?

I recommend that you chose 5120 as well.

Best regards,
Michael

Chris Pickett wrote:
> We've tried to increase the pipe buffer (not bufmod) on FreeBSD this
> week. Besides some tricky implementation details the performance gains
> in a pure 'copy data' benchmark are *astonishing*. Copy time for a
> 5140 buffer (from 512) goes down from 4 mins to 2 mins and for a 20480
> buffer it goes down to 74 seconds (not a linear win but still
> something to consider).
> We'll post patches for FreeBSD next month.
> 
> Chris
> 
> On Fri, Jul 10, 2009 at 8:56 PM, rickey c weisner <rohanrcw at comcast.net> 
> wrote:
>> You can push a bufmod on the fifo and use messages up to the maximum
>> streams message size.
>> rick
>>
>> On Fri, Jul 10, 2009 at 10:48:29AM -0500, Bob Friesenhahn wrote:
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>>> Cc: OpenSolaris Performance/HPC discussions <perf-discuss at 
>>> opensolaris.org>,
>>>       OpenSolaris Shell discussions <shell-discuss at opensolaris.org>,
>>>       Garrett D'Amore <gdamore at sun.com>
>>> Subject: Re: [perf-discuss] Changing the default buffer sizes for pipes ?
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>>> On Fri, 10 Jul 2009, Roland Mainz wrote:
>>>>> Some applications may misbehave or lock-up if the size of the pipe
>>>>> buffer is changed.
>>>> Erm... why ?
>>> You have already noticed that the size is hard-coded in Solaris
>>> applications (by PIPE_BUF) since the dawn of time.  Pipes offer
>>> properties such as atomic reads and writes. PIPE_BUF declares the
>>> maximum size of an atomic write.  Some applications depend on this FIFO
>>> behavior for message passing.
>>>
>>> You should feel happy that Solaris is using 5120 rather than 512 like
>>> FreeBSD.
>>>
>>> Bob
>>> --
>>> Bob Friesenhahn
>>> bfriesen at simple.dallas.tx.us, 
>>> http://www.simplesystems.org/users/bfriesen/
>>> GraphicsMagick Maintainer,    http://www.GraphicsMagick.org/
>>> _______________________________________________
>>> perf-discuss mailing list
>>> perf-discuss at opensolaris.org
>> --
>>
>> Rickey C. Weisner
>> Software Development and Performance Specialist
>> Principal Field Technologist
>> Systems Quality Office
>> cell phone: 615-308-1147
>> email: rick.weisner at sun.com
>> _______________________________________________
>> perf-discuss mailing list
>> perf-discuss at opensolaris.org
>>
> 
> 
> 


-- 
Michael Schulte                                      mschulte at 
sunspezialist.de
OpenSolaris Kernel Development                       http://opensolaris.org/

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