svn commit: r242520 - head/sys/kern

[Daniel O'Connor]

On 04/11/2012, at 7:45, Konstantin Belousov <kostikbel at gmail.com> wrote:
> On Sun, Nov 04, 2012 at 01:08:18AM +0400, Gleb Smirnoff wrote:
>> On Sat, Nov 03, 2012 at 01:35:20PM -0700, Alfred Perlstein wrote:
>> A> Author: alfred
>> A> Date: Sat Nov  3 18:21:40 2012
>> A> New Revision: 242520
>> A> URL: http://svn.freebsd.org/changeset/base/242520
>> A> 
>> A> Log:
>> A>   Retire MAXUSERS.
>> A> 
>> A>   Approved by: peter, meetBSD
>> 
>> This mechanical rename to meaningless (from viewpoint of average
>> operating system user) name is not a retirement. It is just a stupid
>> rename.
>> 
>> FreeBSD source tree isn't a place for stupid jokes. Please back this
>> out.
> 
> Seconded. Unfortunately, this cannot be reverted. At least r242520 shall
> stay as is in repo.


r242520 is actually..

Author:	mckusick
Date:	Sat Nov 3 18:55:55 2012 UTC (12 hours, 6 minutes ago)
Changed paths:	2
Log Message:	
When a file is first being written, the dynamic block reallocation
(implemented by ffs_reallocblks_ufs[12]) relocates the file's blocks
so as to cluster them together into a contiguous set of blocks on
the disk.

When the cluster crosses the boundary into the first indirect block,
the first indirect block is initially allocated in a position
immediately following the last direct block.  Block reallocation
would usually destroy locality by moving the indirect block out of
the way to keep the data blocks contiguous.  This change compensates
for this problem by noting that the first indirect block should be
left immediately following the last direct block.  It then tries
to start a new cluster of contiguous blocks (referenced by the
indirect block) immediately following the indirect block.

We should also do this for other indirect block boundaries, but it
is only important for the first one.

Suggested by: Bruce Evans
MFC:          2 weeks

ie it is a joke :)

--
Daniel O'Connor software and network engineer
for Genesis Software - http://www.gsoft.com.au
"The nice thing about standards is that there
are so many of them to choose from."
  -- Andrew Tanenbaum
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