Messages in this thread | | | Date | Tue, 29 Aug 2000 00:16:22 +0200 | From | Pavel Machek <> | Subject | Re: Suggestion for laptop suspension |
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Hi!
> > is how to mark memory as "unused". I had a theory that the APM BIOS > > suspend code was checking if the memory was all zero's, and not writing > > such pages to disk. This was a while ago, but a quick test didn't seem > > to bear out this theory. > > Are you sure? Maybe the block of zero memory must be continuous at the > end, in which case fragmentation would certainly spoil this. > > No, I'm not sure. As I said, I did a quick test, and when the obvious > thing didn't bear fruit, I lost interest and dropped it. It could have > been that I screwed up the test somehow. It also could have been that > the BIOS was using some other flag value (0xFF, etc.). There's a lot of > really easy tests that could have been done, that I didn't have time to > do. > > There still is the question of whether anything we do to speed this up > would be laptop specific or not. I'm not an APM BIOS expert, so someone > like Stephen Rothwell would be much better equipped to comment on this > issue.
You *dont* need bios support to do suspend-to-disk, as swsusp shows. That is generic across all machines. I believe improving swsusp (it is pretty slow these days, partly because it trashes all caches: it does so by applying artifical memory pressure) is much better project than trying to find out what value do you need in order for BIOS to compress ram. Pavel -- I'm pavel@ucw.cz. "In my country we have almost anarchy and I don't care." Panos Katsaloulis describing me w.r.t. patents at discuss@linmodems.org - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org Please read the FAQ at http://www.tux.org/lkml/
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