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- Date: Sun, 22 May 94 02:20 CDT
- From: ekl@sdf.lonestar.org (Evan K. Langlois)
- To: mint@atari.archive.umich.edu
- Subject: Re-entrancy
-
-
- ========================================================================
- hmm, sure? if we just want IO to halt only processes which are in a
- disk IO systemcall (as opposed to `halt _every_ process' like its now...)
- then we don't need real multithreaded filesystems yet, and i don't think
- the kernel needs much more reentrancy than now like when a process
- sleeps for tty IO. and the SCSI interrupt handler could just reset
- its in-service bit and ipl and then addroottimeout()?
- ========================================================================
-
- If this is possible, I'd REALLY like to see it. It would help ALOT in
- making the OS faster, not to mention practical application. For example,
- recently, all the direct-to-disk recording code I've seen does sector-level
- disk manipulation for speed. This is rediculous, since 16 bit sound,
- at 50Khz is 100K/s, for stereo, you get 200K/s. Just about ANY hard disk
- can handle 200K/s, but the real problem is that you can't overlap disk
- IO with anything else, so you gotta make the disk IO super-fast so it
- doesn't lock up the system too long (at least I guess this is the reason).
-
- Direct-to-disk would get real easy with a nice buffered Minix filesystem
- and non-blocking disk IO. Even if the filesystems weren't multithreaded,
- you could still tfork() the main application. Then a simple circular
- buffer of a modest size could be used for direct-to-disk recording. And
- you'd have CPU time left over to move the mouse too!
-
- Actually, I just hate it when the CPU is wasting time polling in a loop
- when it could be doing something else. I don't care what else, anything
- else. I just hate polling!!
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-