From owner-freebsd-hackers Fri Oct 8 0:18:58 1999 Delivered-To: freebsd-hackers@freebsd.org Received: from anon.lcs.mit.edu (anon.lcs.mit.edu [18.26.0.254]) by hub.freebsd.org (Postfix) with SMTP id 6F65C15405 for ; Fri, 8 Oct 1999 00:18:51 -0700 (PDT) (envelope-from serge69@nym.alias.net) Date: 8 Oct 1999 07:18:50 -0000 Message-ID: <19991008071850.29521.qmail@nym.alias.net> From: Sergey Subject: Is there way to recover system from I/O lockup? To: MIME-Version: 1.0 Content-Type: text/plain; charset="koi8-r" Content-Transfer-Encoding: 7bit Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG Hello. It's relatively simple to force system in swap-in/out loop. The user can produce a lot of processes that use a lot of VM memory, so bringing system to unusable state, due to very big response time (hours). This is also achievable through active IO. I know about defense way - resource limiting, but I'm interested in other way. I do not want to limit someone until this situation. But in case of it, I want be able to enter such system using ssh and "killall" offending processes. Technically speaking, I do not want performance degradation for some running processes and processes forked from them. I do not want to allow swap-out data of this processes and want them to get prioritized IO? (CPU priority, I can get using rtprio. Isn't it?) Is it possible to implement such behavior? Is there any way configure system such way without kernel modification? with kernel modifications? What parts of kernel should I see for it? Thanks in advance, Sergey. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message