Re: PR/50638 CVS commit: src/sys/lib/libsa

[Joerg Sonnenberger <joerg%britannica.bec.de@localhost>]

On Sun, Jan 17, 2016 at 02:10:01PM +0000, Michael van Elst wrote:
> The following reply was made to PR bin/50638; it has been noted by GNATS.
> 
> From: mlelstv%serpens.de@localhost (Michael van Elst)
> To: gnats-bugs%netbsd.org@localhost
> Cc: 
> Subject: Re: PR/50638 CVS commit: src/sys/lib/libsa
> Date: Sun, 17 Jan 2016 14:04:49 +0000 (UTC)
> 
>  joerg%britannica.bec.de@localhost (Joerg Sonnenberger) writes:
>  
>  >cost/benefit analysis. More importantly, it hacks around the symptoms
>  >and doesn't solve the real problem.
>  
>  I agree with you that removing the crc check isn't necessary. But
>  what do you think the real problem is? A non-optimal math routine or
>  a feature being impractical for the user?

Look back at the earlier number -- loading a compressed kernel needs ten
times as much time as zcat from userland. The amount of time spend in
crc32 in either variant, even the bad current libsa version, pales in
comparision. The reason for that factor is almost guaranteed the seeking
in loadfile. I asked if there is a good reason for seeking (or
discarding the data for that matter) before the recent commits, since
that is the issue where 90% of the wasted times goes. I still haven't
received an answer to that question.

Joerg