From owner-freebsd-hackers Tue Jun 17 01:32:42 1997 Return-Path: Received: (from root@localhost) by hub.freebsd.org (8.8.5/8.8.5) id BAA03011 for hackers-outgoing; Tue, 17 Jun 1997 01:32:42 -0700 (PDT) Received: from labinfo.iet.unipi.it (labinfo.iet.unipi.it [131.114.9.5]) by hub.freebsd.org (8.8.5/8.8.5) with SMTP id BAA03006 for ; Tue, 17 Jun 1997 01:32:28 -0700 (PDT) Received: from localhost (luigi@localhost) by labinfo.iet.unipi.it (8.6.5/8.6.5) id KAA17560; Tue, 17 Jun 1997 10:03:42 +0200 From: Luigi Rizzo Message-Id: <199706170803.KAA17560@labinfo.iet.unipi.it> Subject: Re: rtprio from non-root users ? To: joerg_wunsch@uriah.heep.sax.de Date: Tue, 17 Jun 1997 10:03:42 +0200 (MET DST) Cc: hackers@FreeBSD.ORG, luigi@iet.unipi.it In-Reply-To: <19970615103831.BN11477@uriah.heep.sax.de> from "J Wunsch" at Jun 15, 97 10:38:12 am X-Mailer: ELM [version 2.4 PL23] Content-Type: text Sender: owner-hackers@FreeBSD.ORG X-Loop: FreeBSD.org Precedence: bulk > As Luigi Rizzo wrote: > > > I am trying to allow non-root accounts to use CD-R devices. > > The rtprio there is probably overly paranoid. In my original scripts, > i forgot to add the rtprio to the dd part of the pipeline, and i've > been using it this way for quite a long time without any problem. :) I see. On 2.2.X the rtprio commands in burncd.sh are correct :) In light of the recent discussion on disk scheduling etc. it turns out that probably the biggest danger for a correct cd burn is the fact that a process may be starved by another disk-intensive activity (although team is so aggressive that it is unlikely to become the victim of starvation). Next danger on a small-memory system is probably the fact that some of the buffers used by team (or dd ?) might get swapped out. I'd say that if we really want a safer cd write utility, we'd better write a specific program (perhaps just a few patches to "team" would suffice) which does all is needed (from rtrpio to locking buffers in memory etc.) Cheers Luigi -----------------------------+-------------------------------------- Luigi Rizzo | Dip. di Ingegneria dell'Informazione email: luigi@iet.unipi.it | Universita' di Pisa tel: +39-50-568533 | via Diotisalvi 2, 56126 PISA (Italy) fax: +39-50-568522 | http://www.iet.unipi.it/~luigi/ _____________________________|______________________________________