[Ocfs2-devel] [PATCH 1/1] Ocfs2: Treat ocfs2 truncate as a special case of punching holes v1.

[Joel Becker]

On Tue, Jan 26, 2010 at 07:40:05PM +0800, tristan wrote:
> Tao Ma wrote:
> You're absolutely right, as what we expected, the original logic for 
> truncate was the most efficient one, new method using 

<snip>

> 1. Original logic:
> 0.00user 33.06system 0:33.11elapsed 99%CPU
> 
> 2. New logic(using ocfs2_remove_btree_range) from begin to end:
> 0.00user 0.35system 0:00.52elapsed 67%CPU
> 
> 3. New logic(using ocfs2_remove_btree_range) from end to begin:
> 0.00user 1.15system 0:01.16elapsed 98%CPU
> 
> 
> Look, method 1 was up to 100 times efficient than method 2, and 3 times 
> efficient than method 3.

	I'm confused.  You state above that the original method was the
most efficient, yet it took 33 seconds. The remove_btree_range functions
took .35s and 1.15s.  By that measure the original is the worst.  Or am
I reading this wrong?

Joel

-- 

"Up and down that road in our worn out shoes,
 Talking bout good things and singing the blues."

Joel Becker
Principal Software Developer
Oracle
E-mail: joel.becker at oracle.com
Phone: (650) 506-8127