cvs commit: src/share/man/man9 lock.9

[Scott Long]

Maxim Konovalov wrote:
> On Tue, 20 Jun 2006, 16:05-0600, Scott Long wrote:
> 
> 
>>Maxim Konovalov wrote:
>>
>>>On Tue, 20 Jun 2006, 21:41-0000, Maxim Konovalov wrote:
>>>
>>>
>>>
>>>>maxim       2006-06-20 21:41:14 UTC
>>>>
>>>> FreeBSD src repository
>>>>
>>>> Modified files:
>>>>   share/man/man9       lock.9
>>>> Log:
>>>> o Remove LK_REENABLE and LK_NOPAUSE lockinit(9) flags, add LK_NOSHARE.
>>>
>>>
>>>Btw, as I see there are not many consumers of lock.9 infrastructure
>>>comparing to mutex.9, sx.9 etc in our tree.  Is it something derecated?
>>>
>>
>>I guess that VFS doesn't count as being important?
> 
> 
> As an average user I just want to know what pros and contras for using
> lock.9 vs all other locking primitivies.  It is not clear from our man
> pages and arch book.  Sorry if I'm asking something completely stupid.
> 

lockmgr is somewhat analogous to an SX lock.  However, due to some of 
the special considerations needed by VFS in terms of the vnode life 
cycle and blocking for I/O, they aren't completely functionally 
equivalent to an SX lock.  It would be nice to fix VFS to not need these
special considerations, but that is a very complicated and risky task.

Scott