On 18 Aug 2010, at 01:31, Ken Thomases wrote: > On Aug 17, 2010, at 7:26 PM, Shawn Erickson wrote: > >> When you say "free" I assume you mean the "free:" number listed in >> activity viewer for the system as a whole? > >> If so then what you are seeing is an expected result of the "unified >> buffer cache" maintained by the system (since you say private memory >> of your application doesn't increase). In a nut shell unused RAM is >> wasted RAM so the system always attempts to cache once used pages of >> memory (for example file data loaded by your application) as long as >> possible until they need to be reused for active / new allocations. > > In an even smaller nutshell: you should consider Inactive as equivalent to > Free in Activity Monitor's System Memory tab.
I quite understand this, but the practice doesn't quite fit the theory. If 'inactive' is effectively available as 'free' for all apps, then it should be available to my app. And yet, when 'free' drops to just a few megabytes I see extra swap files being created despite there being several gigabytes available as 'inactive', which suggests to me that the unified buffer caching is too aggressive - the cache is being maintained at the expense of swap files. Now, one or two swap files on this machine (an i7 iMac) isn't the end of the world - I don't really notice any system sluggishness until I get more than three swap files. But as the target for this software will likely be a low end Mac, this is a concern - on my 2GB Core Duo MBP this code will kick off so many swap files the machine becomes barely useable. Stuart _______________________________________________ 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: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
