Re: Strange PMAC IDE performance problem

["Albrecht Dreß" <ad@mpifr-bonn.mpg.de>]

Timothy A. Seufert wrote:
[snip]
> Needless to say, the IDE performance figures are far less than those drives
> are capable of!  Under MacOS they benchmark much higher (for example, the
[snip]

I can confirm this behaviour on my PowerBook G3/300 with almost the same rate
under 2.1.130 (the disk is an IBM DYLA 28100). Furthermore, the whole system
nearly freezes under heavy io load (I simply used a program which writes and
reads blocks of data to/from the disk using read and write calls in a loop;
during the run the reaction to console input or a "cat" needs several seconds,
etc.). I posted this problem several times, but got no reaction, so I am glad
that I am not alone ... :-(

The problem might be connected to LOADS of "Bogus interrupts" from do_IRQ in
arch/ppc/kernel/irq.c (try "dmesg" and do a "cat /proc/interrupts" before and
after your test; you will see the increase in the "BAD" line).

I think that this is a serious problem, as it makes the machine nearly unusable
fore some applications. Hope it will get fixed ;-)

Yours, Albrecht.

-- 
+-----------------------------------------------------------------------------+
| Dr.-Ing. Albrecht Dre\3                                      ----           |
| Max-Planck-Institut f"ur Radioastronomie    |\       /      /o  o\          |
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| Mail  ad@mpifr-bonn.mpg.de                                                  |
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