Gary Buhrmaster <gary.buhrmaster(a)gmail.com> writes:
On Mon, Jul 18, 2022 at 6:44 AM Petr Lautrbach
<plautrba(a)redhat.com> wrote:
>
> Dan Čermák <dan.cermak(a)cgc-instruments.de> writes:
> >
> > Just out of curiosity, how large is the speedup typically?
> >
>
> It depends on the number of threads your machine has. But you could get some
> data for comparison using `fixfiles -T 1 restore` and `fixfiles -T 0
> restore` on a running system. The following times are reported on my workstation:
>
Has anyone run such a test on a system using
classic ("spinning rust") HDDs? It is sometimes
the case that parallelizing activities that are I/O
intensive can result in excessive seek activity
that can result in rather elongated elapsed times
(much worse than single threaded operation).
We have only one machine with a rotary HDD and 4 threads:
# for T in 1 0 4; do chcon -R -t root_t /etc/bad-label/; sync; for i in $(seq 1 3); do
echo $i > /proc/sys/vm/drop_caches; done; echo -T $T; time fixfiles -F -T $T restore;
done
-T 1
real 3m32,046s
user 2m0,068s
sys 0m24,005s
-T 0
real 2m32,859s
user 2m9,265s
sys 0m26,775s
-T 4
real 2m38,355s
user 2m9,695s
sys 0m27,042s
Petr