Messages in this thread | | | Date | Sun, 30 Jul 2000 10:44:25 +0200 | From | Ingo Oeser <> | Subject | Re: ORBS Elevator... |
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On Sun, Jul 30, 2000 at 09:39:25AM +0200, Rogier Wolff wrote: > One of the main problems is that in average use, there is just one or > two threads reading stuff from the disk. The threads will be "blocked > waiting for IO to complete" and issue their next IO request after they > have the results of the current IO. So at most there will be just one > or two requests in the disk queue that you can order either the right > way around, or the wrong way around.
Thats why one can use mmap(). This basically lets the OS decide, _when_ to map a page into physical RAM and when to flush it. So we can reorder, as we like. What we miss is a list of pages that should be read or written but do not need to now. This would be nice for servers/workstations, but would harm laptop batteries.
You only suggest it for writes (in the part snipped ;-)), but I would like to see it for (streaming) reads, too.
Regards
Ingo Oeser -- Feel the power of the penguin - run linux@your.pc <esc>:x
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