DragonFly BSD
DragonFly kernel List (threaded) for 2011-12
[Date Prev][Date Next]  [Thread Prev][Thread Next]  [Date Index][Thread Index]

Re: VFS accounting performance benchmarks

From: "Dmitrij D. Czarkoff" <czarkoff@xxxxxxxxx>
Date: Tue, 20 Dec 2011 13:50:53 +0100

On Tue, Dec 20, 2011 at 10:07:22AM +0100, Francois Tigeot wrote:
> Most of the VFS accounting work is now in the tree (and disabled by default,
> enable it with vfs.accounting_enabled="1" in /boot/loader.conf).
> Only a potentially disruptive commit to enable it for / has not been pushed.
> Since VFS accounting uses a per mount-point spinlock to protect its counters, 
> there is some concern it will degrade write performance on SMP machines.
> To measure if this was the case or not, I've run some blogbench benchmarks on
> a small Xeon system; the details of the test and the results are in the
> attached PDF.
> VFS accounting kernel was from 2011-12-19
> Kernel without VFS accounting was from 2011-11-19
> For my part I think the results are inconclusive: either there's no measurable
> performance difference or the choice of benchmark was bad.

I've made a plot which shows the results in more evident way (if I correctly
understand the test results data).

Dmitrij D. Czarkoff

Attachment: vfsa.svg
Description: image/svg

Attachment: vfsa.png
Description: PNG image

[Date Prev][Date Next]  [Thread Prev][Thread Next]  [Date Index][Thread Index]