Re: a joint letter on low latency and Linux

[Khimenko Victor]

In <[e-mail]> Mark Hahn ([e-mail]) wrote:
>> On Thu, 29 Jun 2000, Paul Barton-Davis wrote:
>> >that an IDE-based disk subsystem has much worse impact on latency,
>>
>> use hdparm -u1 if you need good irq latency.

> -u1 is a nasty workaround.  -d1 is the fix, since if you're
> doing the kind of audio people are talking about, you don't want
> PIO eating your CPU either.  also PIO SCSI/net/etc, of course.

In fact -u1 is GREAT thing to show what Linus DOES accept and what he DOES NOT.
Wihout -u1 interrupt latency is so high somethimes that you can not use serial
ports and some other stuff (-d1 is fix, but it's not always awailable). And
even if it's horrible KLUDGE (and everyone knows it!) it's LOCALIZED kludge.