Pre-caching disk blocks in memory..

[DanKarron at UCBVAX.BERKELEY.EDU]

Here's the problem: Loading pixels from disk is limited by the speed that
the disks can unload.

Graphics performance can appear to suffer due to io limitations.

Proposed solution: The operating system saves disk blocks in memory
in some fashion, but purges them when memory gets tight. I have
tried running some trivial program such as wc on image files prior to
putting them up with ipaste. 

Now: How can I pin a disk block/page in memory because I know that I will
be trying to open it at some time in the future. Then, How can I tag
a block as free after I know I will not need it ?

Are there any diagnostics to keep track of disk blocks in memory ? 
Any way to keep stats on cache hits/misses ? 

My application is to load into memory pixels that my user will probablly
want to look at while he/she is still looking at the name of the
pixel file. Then when the user decides that they want to look at it, it
will already be in memory, and the delay while the disk unloads will have
already passed.

Cheers!

dan.
| karron at nyu.edu (e-mail alias )         Dan Karron, Research Associate      |
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