Re: 2.0.30 serial.c, ppp.c and pppd-2.2 questions
Fri, 25 Jul 1997 02:58:49 +0200

Theodore Y. Ts'o:

: Date: Thu, 24 Jul 1997 00:06:25 +0200
: From:

: Possibly entirely unrelated (you are talking about missed timer interrupts,
: probably I am talking about missed serial line interrupts) but
: my SLIP connection is completely unusable when something disk-intensive
: is running. FTP gets into an exponential backoff and seems to hang
: completely, but recovers some time after the make/find/whatever has
: finished.

: [This happens both with IDE and SCSI activity. I never really
: investigated.]

: At least for the IDE case, this is the very well known problem of the
: IDE driver disabling interrupts to prevent data corruption in a few
: badl;y designed IDE controllers. If you don't have the bad IDE
: controllers (see the man page for more details), you will likely be able
: to use "hdarm -u 1" which will fix the problem without causing your
: disks to get massively corruption.

: As far as the SCSI activity, my guess it is a similar problem, but the
: solution to solve it is very dependent on the SCSI manufacturer.

: - Ted

You are an optimist.
(On the one hand "hdparm -u 1" does cause corruption here,
on the other hand, it doesnt help at all.)

Suppose something is wrong in the scheduler, and processes
with finished disk I/O get too much attention.
I just showed my son how an e2fsck on a large SCSI disk really
stopped all other activity.