Path: ...!feed.opticnetworks.net!eternal-september.org!feeder3.eternal-september.org!news.eternal-september.org!.POSTED!not-for-mail
From: Stefan Monnier <monnier@iro.umontreal.ca>
Newsgroups: comp.arch
Subject: Re: Privilege Levels Below User
Date: Wed, 12 Jun 2024 10:52:20 -0400
Organization: A noiseless patient Spider
Lines: 19
Message-ID: <jwvplsmdxnk.fsf-monnier+comp.arch@gnu.org>
References: <jai66jd4ih4ejmek0abnl4gvg5td4obsqg@4ax.com>
	<Z9I8O.13$2JEf.11@fx14.iad> <5h%8O.4327$wDZ.776@fx48.iad>
	<1316e4baa439de908666e38c39cd8c79@www.novabbs.org>
	<ywE9O.33$46t.1@fx46.iad> <v47avm$ht65$1@dont-email.me>
	<nFH9O.398$jzkf.157@fx06.iad> <v490co$v1vj$1@dont-email.me>
	<20240611131223.00005cb4@yahoo.com> <gyhaO.1069$Cqra.277@fx10.iad>
MIME-Version: 1.0
Content-Type: text/plain
Injection-Date: Wed, 12 Jun 2024 16:52:21 +0200 (CEST)
Injection-Info: dont-email.me; posting-host="d3b02c79f9f0beffc48d715e1d5c7f90";
	logging-data="1797448"; mail-complaints-to="abuse@eternal-september.org";	posting-account="U2FsdGVkX18JSfRDkkzC1ywkI71lgfwAfw4+TomtVhQ="
User-Agent: Gnus/5.13 (Gnus v5.13)
Cancel-Lock: sha1:hCub7BEbWuk/7Axv7Q6VvaCYTRg=
	sha1:0ulfvvqzjrQvTdp5QjNo/sgFMIw=
Bytes: 2081

>> I think, Eric more than a little exaggerates about the level of
>> complexity of end-of-interrupt processing needed in common case.
>> May be, the code is long, but absolute majority of it is executed very
>> rarely, if at all.
> Possibly, as I do have a tendency to get somewhat animated about this.
> I can't find it just now but a while back I was looking at some
> Linux source code for the x86 interrupt return path,
> and it went on for page after page after page.

Beside the code size cost and associated runtime impact, there's also
the fact that this complexity inevitably comes with an increased risk
of bugs.

Nick McLaren could go on and on about this as an infinite source of bugs
that are so hard to track down that they're basically never even
diagnosed correctly (let alone fixed).


        Stefan