ZFS on top of GELI / Intel Atom 330 system

[Emil Mikulic]

On Fri, May 29, 2009 at 12:47:38PM +0200, Morgan Wesstr?m wrote:
> You can benchmark the encryption subsytem only, like this:
> 
> # kldload geom_zero
> # geli onetime -s 4096 -l 256 gzero
> # sysctl kern.geom.zero.clear=0
> # dd if=/dev/gzero.eli of=/dev/null bs=1M count=512

I don't mean to take this off-topic wrt -stable but just
for fun, I built a -current kernel with dtrace and did:

	geli onetime gzero
	./hotkernel &
	dd if=/dev/zero of=/dev/gzero.eli bs=1m count=1024
	killall dtrace
	geli detach gzero

The hot spots:
[snip stuff under 0.3%]
kernel`g_eli_crypto_run                                    50   0.3%
kernel`_mtx_assert                                         56   0.3%
kernel`SHA256_Final                                        58   0.3%
kernel`rijndael_encrypt                                    72   0.4%
kernel`_mtx_unlock_flags                                   74   0.4%
kernel`rijndael128_encrypt                                 74   0.4%
kernel`copyout                                             92   0.5%
kernel`_mtx_lock_flags                                     93   0.5%
kernel`bzero                                              114   0.6%
kernel`spinlock_exit                                      240   1.3%
kernel`bcopy                                              325   1.7%
kernel`sched_idletd                                       810   4.3%
kernel`swcr_process                                      1126   6.0%
kernel`SHA256_Transform                                  1178   6.3%
kernel`rijndaelEncrypt                                   5574  29.7%
kernel`acpi_cpu_c1                                       8383  44.6%

I had to build crypto and geom_eli into the kernel to get proper
symbols.

References:
  http://wiki.freebsd.org/DTrace
  http://www.brendangregg.com/DTrace/hotkernel

--Emil