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

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

On Sun, Jan 17, 2016 at 04:40:01AM +0000, Izumi Tsutsui wrote:
> The following reply was made to PR bin/50638; it has been noted by GNATS.
> 
> From: "Izumi Tsutsui" <tsutsui%netbsd.org@localhost>
> To: gnats-bugs%gnats.NetBSD.org@localhost
> Cc: 
> Subject: PR/50638 CVS commit: src/sys/lib/libsa
> Date: Sun, 17 Jan 2016 04:35:42 +0000
> 
>  Module Name:	src
>  Committed By:	tsutsui
>  Date:		Sun Jan 17 04:35:42 UTC 2016
>  
>  Modified Files:
>  	src/sys/lib/libsa: cread.c
>  
>  Log Message:
>  Add an option (LIBSA_CREAD_NOCRC) to disable gunzip CRC32 calculation.
>  
>  No obvious sideeffect on booting i386 GENERIC kernels (without the option).
>  Closes PR/50638 (Extreme slowness on loading gzipped kernels on old CPUs).

Please revert this.

(1) The commit message is wrong, it has been clearly demonstrated that
the CRC code *does* provide obvious side-effects.

(2) The offered patches fixes the stated original original problem to
within a small degree of the cost of uncompression.

(3) Fixing the real problem of repeated uncompression would make (2)
even less a problem.

Stop adding hacks on top of hacks.

Joerg