Re: Suggestion for laptop suspension

From: Theodore Y. Ts'o (tytso@MIT.EDU)
Date: Mon Aug 28 2000 - 11:33:02 EST

   Date: Mon, 28 Aug 2000 11:04:50 +0200
   From: Marc Lehmann <>

   On Sun, Aug 27, 2000 at 07:10:26PM -0400, "Theodore Y. Ts'o" <tytso@MIT.EDU> wrote:
> 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

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

                                                - Ted

To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to
Please read the FAQ at

This archive was generated by hypermail 2b29 : Thu Aug 31 2000 - 21:00:21 EST