The subject line is incorrect. Swap is the portion of virtual memory which is not physical. What you should have said is "swap not a substitute for *physical* memory". -- Allen Brown http://brown.armoredpenguin.com/~abrown
> At Wed, 16 Apr 2008 13:18:29 -0400, > Ian Lawrence wrote: >> >> Hi, >> > The issue is more that the whole "Web 2.0" hasn't been planned to be >> run >> > in 64MB of RAM. There are sites out there where a single Flash >> object >> > or JavaScript script consumes more memory. Even 128MB is tight. >> But, I mean it is possible to increase the amount of memory available >> for a 770 using an MMC card, right?. I am not sure what the upper >> limit is but 128MB + 64MB of system memory seems feasible. > > You are confused about what swap is. Swap allows the memory manager > to page (save) anonymous memory to backing store (which in this case > is your disk). > > If union of the working set of the active applications (the memory > they need to run with only a trivial amount of faults, i.e., page-ins) > exceeds the amount of *RAM*, then your system thrashes. As disk is > several orders of magnitude slower than RAM, in such a case, your > system makes no useful progress and will appear to you to have frozen. > > The advantage of swap then, is that if you are running e.g. Mozilla > and its working set is large, then the memory manager can page the > anonymous memory of background applications (as well as the anonymous > memory that Mozilla uses, which is hopefully inactive). > > Without swap, the only data that the memory manager can page is that > associated with files. So, program and library text, data files, etc. > The problem is that most programs don't use the disk format for the > data they use: on bringing it into memory, they convert it to a form > useful for in-memory operations. Thus, a lot of the memory on your > system will be occupied by such computed data, which, without swap, is > locked in memory until it is explicitly freed. > > > For what it is worth, after I removed /usr/bin/metalayer-crawler, my > system went from being completely unusable for anything but being a > broken alarm clock to being relatively useful. > _______________________________________________ > maemo-developers mailing list > maemo-developers@maemo.org > https://lists.maemo.org/mailman/listinfo/maemo-developers > _______________________________________________ maemo-developers mailing list maemo-developers@maemo.org https://lists.maemo.org/mailman/listinfo/maemo-developers
