expand vfsops for compat

[Alfred Perlstein]

On 8/23/13 3:35 PM, Xin Li wrote:
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> On 08/23/13 15:15, Alfred Perlstein wrote:
>> Index: sys/mount.h
>> ===================================================================
>>
>>
> - --- sys/mount.h	(revision 254717)
>> +++ sys/mount.h	(working copy) @@ -628,6 +628,12 @@
>> vfs_susp_clean_t	*vfs_susp_clean; vfs_notify_lowervp_t
>> *vfs_reclaim_lowervp; vfs_notify_lowervp_t	*vfs_unlink_lowervp; +
>> vfs_mount_t		*vfs_spare1; +	vfs_mount_t		*vfs_spare2; +	vfs_mount_t
>> *vfs_spare3; +	vfs_mount_t		*vfs_spare4; +	vfs_mount_t
>> *vfs_spare5; +	vfs_mount_t		*vfs_spare6; };
> Can this be just vfs_mount_t *vfs_spare[6]?  Also, why 6 slots?  (We
> currently have 17 vfsops, 17+6=23 is a prime number but I don't think
> we really need a prime number here :).
>
> Cheers,
> - -- 
> Xin LI <delphij at delphij.net>    https://www.delphij.net/
> FreeBSD - The Power to Serve!           Live free or die
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The reason I picked 6 was because the last set of changes to nullfs 
added *3*, so I figure hedging 2x that is a good bet.

Also prime numbers hash better so why not? :)

About using arrays, arrays are slower than direct member access because 
of compiler issues so .. ...if you are still reading this sentence I am 
joking. :)

Sure, I'll switch to an array.


-- 
Alfred Perlstein