Date: Tue, 28 Apr 1998 16:03:54 -0400 (EDT) From: "Adrian T. Filipi-Martin" <atf3r@cs.virginia.edu> To: Garance A Drosihn <drosih@rpi.edu> Cc: freebsd-hackers@FreeBSD.ORG Subject: Re: SIGDANGER Message-ID: <Pine.SOL.3.96.980428155610.4518G-100000@mamba.cs.Virginia.EDU> In-Reply-To: <v0401170bb16b52903bec@[128.113.24.47]>
next in thread | previous in thread | raw e-mail | index | archive | help
On Tue, 28 Apr 1998, Garance A Drosihn wrote: > If you have a system which does overallocate, you're going to randomly > pick processes to kill. Or maybe the system will even make a pretty > good guess at what to kill. That is a true statement with or without > SIGDANGER. The question is, will there be any way for some critical > process (system daemons, the X-server, whatever) to tell the system > "No, don't kill me, try to kill someone else first!". > > The example you give isn't particularly interesting, as I (as a system > administrator) don't really care if any or all of those pittly little > processes ( :-) ) get killed. I may, however, be very unhappy if sshd > or the main lpd process gets killed just because they *happen* to be > the process which requests memory at the wrong time while you're running > that "danger.c" program. Ok. I'll buy that. My concearn is that every process of "interest" will need to have a SIGDANGER handler added. Just because my shell didn't have a handler, doesn't mean I want it killed off. I see that presently there is no security in the present situation and that it may get killed off anyway. If a default handler for SIGDANGER were provided that prevented a process form being killed on the first SIGDANGER and instead flushed any freed memory in the malloc free lists, and then only on the second reception of SIGDANGER tried to exit, I would feel more comfortable. A second chance handler like this seems reasonable as it may free up some resources without killing too many processes needlessly. Adrian -- adrian@virginia.edu ---->>>>| If I were stranded on a desert island, and System Administrator --->>>| I could only have one OS for my computer, Neurosurgical Visualization Lab ->>| it would be FreeBSD. Think about it..... http://www.nvl.virginia.edu/ ->| http://www.freebsd.org/ To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?Pine.SOL.3.96.980428155610.4518G-100000>