svn commit: r270648 - in head/sys: kern sys

[John Baldwin]

On Tuesday, August 26, 2014 4:17:22 am Mateusz Guzik wrote:
> Author: mjg
> Date: Tue Aug 26 08:17:22 2014
> New Revision: 270648
> URL: http://svnweb.freebsd.org/changeset/base/270648
> 
> Log:
>   Fix up races with f_seqcount handling.
>   
>   It was possible that the kernel would overwrite user-supplied hint.
>   
>   Abuse vnode lock for this purpose.
>   
>   In collaboration with: kib
>   MFC after:	1 week

Do we care about this being correct enough to penalize reads by single-
threading them?  This is just an optimization, if you lose the race it doesn't 
actually break anything.

-- 
John Baldwin