From owner-freebsd-hackers Mon Apr 27 14:25:38 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id OAA11967 for freebsd-hackers-outgoing; Mon, 27 Apr 1998 14:25:38 -0700 (PDT) (envelope-from owner-freebsd-hackers@FreeBSD.ORG) Received: from att.com (kcgw1.att.com [192.128.133.151]) by hub.freebsd.org (8.8.8/8.8.8) with SMTP id OAA11945 for ; Mon, 27 Apr 1998 14:25:12 -0700 (PDT) (envelope-from sbabkin@dcn.att.com) From: sbabkin@dcn.att.com Received: by kcgw1.att.com; Mon Apr 27 16:25 CDT 1998 Received: from dcn71.dcn.att.com ([135.44.192.112]) by kcig1.att.att.com (AT&T/GW-1.0) with ESMTP id QAA11065 for ; Mon, 27 Apr 1998 16:25:05 -0500 (CDT) Received: by dcn71.dcn.att.com with Internet Mail Service (5.0.1458.49) id ; Mon, 27 Apr 1998 17:24:28 -0400 Message-ID: To: freebsd-hackers@FreeBSD.ORG, dec@phoenix.its.rpi.edu Subject: RE: SIGDANGER Date: Mon, 27 Apr 1998 17:24:26 -0400 X-Priority: 3 MIME-Version: 1.0 X-Mailer: Internet Mail Service (5.0.1458.49) Content-Type: text/plain Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG > ---------- > From: David E. Cross[SMTP:dec@phoenix.its.rpi.edu] > > I was recenlty shown AIX's SIGDANGER (33). It is a signal that the > kernel > issues to [some] running processes when it gets dangerously low on > space, > by default SIGDANGER causes programs to die, freeing up memory, system > critical processes and server processes woulf be compiled to ignore > SIGDANGER. This seems like a very good idea, could it be done in > FreeBSD? > I remember someone talking about changing the signal structs to be an > array of INTs, instead of just an int to accomidate more than 32 > signals. > I guess, it it not applicable to BSD. If FreeBSD uses the same space allocation method that is described in the devil book, it will not allow a process to start if it does not have enough swap space. On the other hand, AIX does speculate and can end up with swap space shortage at any point of time, not only in fork/exec/mmap/sbrk code. -Serge To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message