On Saturday, December 31, 2005 @ 2:04 AM, Carlos Robinson wrote:
The Friday 2005-12-30 at 16:53 -0900, Greg Wallace wrote:
Correct; but not only binaries, but everything.
But just the read only portion is cached, right?
No, also the write operations are cached. I understand that the kernel then sorts the pending write operations to try minimize disk head movements (I saw somewhere keywords to select the sorting algorithm). You can dissable write cache operations with the option "sync" in fstab; for example, if you automount media like floppies or external drives, they are normally mounted sync, so they can be removed fast: but they are slow when writing because the cache is dissabled, mounted sync.
(temporary storage holding values you input but not saved) is modified by what you do while you're modifying a data file but that doesn't change what's cached. The cached copy is just a blank slate, suitable for a pure memory to memory copy if you exit the app and then call it back up. I wouldn't think that any special/seldom used forms would be loaded by default either, but would only be loaded if you actually went to one of those during your edit session. Probably just the initial form that you see when you start the app (and maybe a few commonly used ones) is loaded when you call up the app the first time.
No, the cache doesn't know about forms or any application internals. It just copies the disk sectors or files into memory and operates there, in memory. If the cache is dirty, modified, then it will be saved to disk promptly, but not inmediately. It is not only binaries, but any file.
For the exact details, you would have to ask a kernel developper :-)
- -- Cheers, Carlos Robinson
But if I exit an app and then call it back up, I don't want to have any "data" from the previous execution. In order to get that so called clean slate, the app has to either get the clean slate (so to speak) from disk or from cache. So, a clean copy should be in the cache ready to serve up if I try to call the app up again later in my session. At least that's the way I understand it to work in the 'doze world. Greg Wallace