Re: [Gnu-arch-users] Re: [PATCH] arch speedups on big trees

[Chris Mason]

On Fri, 2004-01-09 at 10:11, Aaron Bentley wrote:

> > Vanilla arch tries to avoid the read as well, checking against the inode
> > sig.  But it does this after restating the files, so an early check is a
> > good thing (haven't read your patch, sorry).
> 
> Yes, it looked like that was what it was doing.  I'm using the inode and
> device to determine if one file is the same as the other.
> 
> > A command to relink the project tree to the revision library or pristine
> > tree will probably help keep the tree from slowing down over time.  
> 
> You could do "tla changes --relink" with very little pain, updating
> links when files compare the same.
> 
> >The hard link stuff is a huge performance win.
> 
> Actually, I haven't seen a huge win where I expected to.  tla changes on
> a hardlinked tree is just 1.05x faster than tla changes on a normal
> tree.  The system time was pretty much the same.
> 
> Mind you, that was a pokey box, but you'd expect the system time to go
> down, and it basically didn't.  Perhaps it was because I'd "primed" the
> system by running tla changes first.
> 
Somethings sounds off there, but I guess it depends on how big your tree
is.  You might want to add a few printfs to make sure you're really
skipping the reads on linked files.

-chris