On 5 Dec 2012, at 02:58, Kyle Sluder <k...@ksluder.com> wrote: > On Tue, Dec 4, 2012, at 10:15 AM, Gerriet M. Denkmann wrote: >> I have an app which uses NSOperations inside an NSOperationQueue. These >> operations do not do any I/O - just Cpu. No swapping is taking place. >> >> When I set [ self.operationQueue setMaxConcurrentOperationCount: 1 ] each >> operation takes on average 200 msec., measured by NSDate. >> >> With 2 concurrent operations, it takes not 100 msec but 110 - an extra >> 10%. Ok - some overhead is to be expected. >> >> With 4 ops it takes 70 instead of 50 - overhead 40% - rather a lot. >> With 8 ops it takes 60 instead of 25 - overhead 140%. or: 40% of the cpu >> is used by my operations, 60% is used by whom? And for what? >> >> Is this to be expected? Or does my app has some hidden flaws? If so, >> where should I start looking? > > How many operations are you creating? We've found that with more than a > few hundred operations, NSOperationQueue is unusable.
In this test I was using 444 operations. Otherwise there might be many thousands. Just tried again with 44 operations, but did not see any change in average execution time. Kind regards, Gerriet. _______________________________________________ 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
