On Nov 6, 2012, at 9:23 AM, Jean-Daniel Dupas wrote: > > Le 6 nov. 2012 à 12:13, Tom Davie <tom.da...@gmail.com> a écrit : > >> >> On 6 Nov 2012, at 11:01, Nick Rogers <roger...@mac.com> wrote: >> >>> Hi, >>> >>> Thanks for the replies. >>> I was trying to achieve what essentially "free memory" apps on the Mac >>> AppStore do. >>> The RAM usage can be divided into four parts as shown in Activity Monitor. >>> 1. Free >>> 2. In-active >>> 3. Active >>> 4. Wired >>> >>> When I used my earlier app to allocate memory equal to free + inactive >>> bytes, for the execution of the program it used to make the system less >>> responsive for a few seconds and on release and quitting the app, most of >>> the inactive memory would shift under free. >>> >>> e.g. if free is 1GB and inactive is 1.5GB, then after run, free would be >>> 2.45GB and inactive just 50MB. >> >> Why on earth would you want to release inactive memory? This is memory that >> is in use by applications, just ones that haven't been scheduled in for a >> while. This RAM IIRC is automatically paged out to disk, so that if it is >> needed it can simply be overwritten, just like free memory, but has the side >> benefit that if it's not overwritten, then the inactive applications can be >> brought back to life very fast. > > The memory is paged out to disk only if it is read-write memory that was > modified, and is not already on the disk. All mapped frameworks, the full > content of the "Unified Buffer Cache" (which generally represent most of the > inactive memory) and other stuff are keep in RAM to provide faster access, > but are already present on disk and will be simply discarded if the system > need more RAM. > > So not only freeing inactive memory is useless, but it is also guarantee to > make your system slower.
Actually, that's not always the case. As I use Safari through out the day, Safari ends up eating 6 to 12 GB of data on my 16 GB system. Frequently, I need to issue a purge to get back a spare GB or few hundred MB. Plus, if you're booting off, or have your swap file on an SSD disk related performance penalties will be much less than if using an HD to hold the swap file. OK, yes, it will be slower, but it might not be noticeable. And from what I've seen, many web site creators aren't treating each of their pages as if they should be memory controlled. Turning off JavaScript certainly prevents much of this bloat. _______________________________________________ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
