> From: Bartlomiej Zolnierkiewicz [mailto:[email protected]]
>
> On Wed, 30 Mar 2005 13:52:05 +0200, kus Kusche Klaus
> <[email protected]> wrote:
> > However, things break seriously when exercising the CF card
> in parallel
> > (e.g. with a dd if=/dev/hda of=/dev/null):
> >
> > * The rtc *interrupt handler* is delayed for up to 250
> *micro*seconds.
> > This is very bad for my purpose, but easy to explain: It is
> roughly the
> > time needed to transfer 512 Bytes from a CF card which can
> transfer 2
> > Mbyte/sec, and obviously, the CPU blocks all interrupts
> while making pio
> >
> > transfers. (Why? Is this really necessary?)
> >
> > (I know because I instrumented the rtc irq handler with
> rdtscl(), too)
>
> hdparm -u1 /dev/hda
>
> should help
Hmmm, thanks, that sounds very reasonable, and I didn't know that flag.
Unfortunately, it doesn't help. The bad timings stay the same (still
delays in the 30-300 ms range), the number of context switches stays the
same, ...
The only thing which changes is the CPU load shown by vmstat:
* With -u0, I have 1 % user, ~50 % sys, ~50 % wa
* With -u1, I have 1 % user, ~98 % sys, 1 % wa
P.S.: Apologies for my badly formatted mails. The company forces us to
use outlook, we may not even change the settings...
Klaus Kusche
>Entwicklung Software - Steuerung
>Software Development - Control
>
>KEBA AG
>A-4041 Linz
>Gewerbepark Urfahr
>Tel +43 / 732 / 7090-3120
>Fax +43 / 732 / 7090-8919
>E-Mail: [email protected]
>www.keba.com
>
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[Index of Archives]
[Kernel Newbies]
[Netfilter]
[Bugtraq]
[Photo]
[Stuff]
[Gimp]
[Yosemite News]
[MIPS Linux]
[ARM Linux]
[Linux Security]
[Linux RAID]
[Video 4 Linux]
[Linux for the blind]
[Linux Resources]
