On Sat, 29 Dec 2001 19:13:48 +0100 (CET), [EMAIL PROTECTED] wrote:

> Hi!
> 
> I have measured the time it takes to boot Linux on Q40 (starting at the
> penguin):
> 
> Kernel 2.2.17 : 62 sec
> Kernel 2.4.17 : 36 sec
> 
> I used the same installation, of course.
> Thierry, your kernel seems to be mega fast.

Well, Linux v2.4 is known (and designed) to be faster than v2.2, but
beyong that, I used the 68060 optimisation flag (-m68060) to compile
the Q60 kernel and the -m68040 flag for the Q40 kernel: the proper
flag can be selected when configuring the kernel (make menuconfig
or make xconfig), by selecting ONLY ONE of the 68020 / 68030 / 68040 /
68060 support options. If you select two of them (e.g. 68040 & 68060
for the Qx0), then no optimization flag is used at all (!) for the
compilation (thus defaulting to a 68000-compatible code and also
probably avoiding any 68000 instruction that would not work on higher
processor, e.g MOVE.W SR,Dn which is priviledged on 68020+).

The use of proper optimization surely makes the kernel MUCH faster !

Thierry.

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