Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!cis.ohio-state.edu!ucbvax!UCBVAX.BERKELEY.EDU!"Dan Karron From: Dan Karron@UCBVAX.BERKELEY.EDU Newsgroups: comp.sys.sgi Subject: Pre-caching disk blocks in memory.. Message-ID: <9106112151.AA24876@karron.med.nyu.edu> Date: 11 Jun 91 21:51:50 GMT Sender: daemon@ucbvax.BERKELEY.EDU Reply-To: karron@cmcl2.nyu.edu Distribution: world Organization: The Internet Lines: 32 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@nyu.edu (e-mail alias ) Dan Karron, Research Associate | | Phone: 212 263 5210 Fax: 212 263 7190 New York University Medical Center | | 560 First Avenue Digital Pager <1> (212) 397 9330 | | New York, New York 10016 <2> 10896 <3> |