Date: Mon, 13 Mar 2000 00:37:10 +0100 From: Gary Jennejohn <garyj@peedub.muc.de> To: freebsd-hackers@FreeBSD.ORG Subject: Re: 5.0 features? Message-ID: <200003122337.AAA25674@peedub.muc.de> In-Reply-To: Your message of "Sun, 12 Mar 2000 15:11:51 CST." <200003122111.PAA19501@freebsd.netcom.com>
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Mark Hittinger writes: > >Something that the old DEC took a few stabs at was the idea of a >"checkpoint" feature where a process or a series of processes could be >put in a quiesced state. This would page out the process or processes >into the swap space, allow a hardware shutdown, and after a reboot allow >the restart of the checkpointed process(es). > I did something like this for Philips while I was at UniSoft. It depended on some special hardware features (turning off/losing power generated an interrupt, there was a small UPS in the box along with battery-backed SRAM to save various kernel structures). Turning off the power caused all memory to be saved to disk (the kernel turned off the UPS after it was done). Upon a restart the kernel noticed that memory had been saved, read the contents in from disk, futzed around with some structures, and restarted what was curproc at the time of shutdown. It even worked ;-) Philips never did anything with it. --- Gary Jennejohn / garyj@muc.de garyj@fkr.cpqcorp.net gj@freebsd.org To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
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