Malloc error "can't allocate region" failed with error code 12. Any idea how to resolve this?

Question

i am getting this error and dont know what to do with that:

AppName(3786,0xa0810540) malloc: *** mmap(size=16777216) failed (error code=12)
*** error: can't allocate region
*** set a breakpoint in malloc_error_break to debug

If i set a breakpoint to that line that occurs the error, i dont know what i have to search specially for. In instruments i have checked the allocations and the value is increasing until 14,5 GB of all allocations.

Can someone give me help?
brush51

EDIT 1:
More informations:
- I am trying this in the simulator, not on the iOS device.
- Thats all of the output(i am getting this error more times). - the error occurs on this line:

NSManagedObjectContext *context = [self managedObjectContext];
NSFetchRequest *fetchREntitySetsCards = [[[NSFetchRequest alloc] init] autorelease];
//NSFetchRequest *fetchREntityRelCardsAnswersNotes = [[[NSFetchRequest alloc] init] autorelease];

NSEntityDescription *entitySetsCards = [NSEntityDescription entityForName:@"EntitySetsCards" inManagedObjectContext:context];
//NSEntityDescription *entityRelCardsAnswersNotes = [NSEntityDescription entityForName:@"EntityRelCardsAnswersNotes" inManagedObjectContext:context];
setEntity:entityCard];
[fetchREntitySetsCards setEntity:entitySetsCards];
//[fetchREntityRelCardsAnswersNotes setEntity:entityRelCardsAnswersNotes];

NSArray *fetchedObjSetsCards    = [context executeFetchRequest:fetchREntitySetsCards error:&error];
//The error is here--->
//NSArray *fetchedObjRelCardsAnswersNotes   = [context executeFetchRequest:fetchREntityRelCardsAnswersNotes error:&error];


//Badges für TabBarItem Inbox setzen
setsCount = [context countForFetchRequest:fetchREntityUserSet error: &error];
cardsCount = [context countForFetchRequest:fetchREntityCard error: &error];

Answer 1

Sounds strange, but I had the same behavior when main thread was overloaded.

Memory usage was optimal enough: instruments shows no leaks and live memory was about 2Mb, no memory warnings while running on a device, all massive allocation was done inside autorelease pools etc.

But there was very huge process of storing data to db (using Core Data) made on main thread. Just moving the storing code to background process like this

dispatch_async(dispatch_get_global_queue
  (DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
  BOOL result = NO;
  result = [[DataManager sharedInstance] storeGuestsToDB];
  dispatch_async(dispatch_get_main_queue(), ^{
  //finalization
  }
}

fixed my problem.

Answer 2

Googling will reveal quite a few tutorials on using instruments to understand what is going on with your memory:

How to debug memory leaks: (tutorial)
http://www.raywenderlich.com/2696/how-to-debug-memory-leaks-with-xcode-and-instruments-tutorial

And another:
Finding Obj-C memory leaks (video)
http://www.youtube.com/watch?v=R449qEuexNs&feature=related

*There are many similar questions on stackoverflow you might benefit from.