Reminder: NET_NEEDS_GIANT, debug.mpsafenet going away in

Scott Bennett bennett at cs.niu.edu
Wed Jul 18 19:54:49 UTC 2007


     On Wed, 18 Jul 2007 20:48:21 +0100 (BST) Robert Watson
<rwatson at FreeBSD.org> wrote:

>On Wed, 18 Jul 2007, Scott Bennett wrote:
>
>>  [Cc: list trimmed a bit more  --SB]
>>     On Tue, 17 Jul 2007 23:42:14 +0200 Max Laier <max at love2party.net>
>>
>>> [ Excess CC-list ... testers needed!!! ]
>>>
>>> On Tuesday 17 July 2007, Robert Watson wrote:
>>
>>     I missed Robert Watson's start of thread, so I'm jumping in here
>> with a question.
>>
>>>> This is a reminder e-mail that, in the very near future, Giant 
>>>> compatibility shims for network protocols will be removed.
>>
>>     How, if at all, will this affect qemu users?  qemu exits unless AIO is 
>> present in the kernel (or aio.ko has been kldload-ed).  In FreeBSD 6.2, AIO 
>> results in a warning message at boot time that says AIO is not MPSAFE and 
>> that therefore the networking stack will take a deep performance hit.
>
>Per several earlier e-mails in the thread, AIO is MPSAFE in FreeBSD 7.0 and, 
>as such, unaffected by this change.  As a result, I would expect that 
>applications depending on AIO should now perform significantly better (but 
>have done no measurement in this area).
>
     Great!  Thanks for this news.  My apologies for missing the previous
messages.


                                  Scott Bennett, Comm. ASMELG, CFIAG
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