Re: measuring swap partition speed

On Sat, Dec 23, 2023 at 11:55:43AM -0800, Mark Millard wrote:

>That last indicates another potentially significant difference
>from my example benchmarks done for comparison to yours:
>
>GEOM_ELI: Device da0p3.eli created.
>GEOM_ELI: Encryption: AES-XTS 256
>GEOM_ELI: Crypto: software
>
>That likely contributes to slowing down I/O for da0p3 and
>possibly to leaving less time for I/O to other partitions
>when da0p3 is in use.

I think *some* slowdown is reasonable. What's happening here, though,
amounts to blocking. 300-1000Kb/s against 16MB.

zfs filesystem reads/writes are slower to an extent but it's
not by a massive amount, like it is with swap, (and the swap 
is unencrypted)

>If you had the resources to test avoiding the encrypted
>partition for your type of media, that might prove
>interesting.

I think i did early on but I can do so again. I'll delete
some swap partitions and format as ufs.

>I've never had occasion to want to use any encrypted
>partitions for my FreeBSD activity.

A couple of reasons for this particular instance:

1. the hardware is portable and visible and would be easily
    stolen by someone of a mind to

2. the system performs authentication of which some parts
    are in clear txt

>I'm unsure of the GEOM_ELI processing-time contributions
>vs. "gstat -spod" reporting.

yeah I've long wanted to measure the performance penalty for this,
given that theres no aesni or equivalent capability available in the 
hardware.
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