Re: dispatch_async Performance Issues
Re: dispatch_async Performance Issues
- Subject: Re: dispatch_async Performance Issues
- From: Jonathan Taylor <email@hidden>
- Date: Tue, 28 Jun 2011 14:53:33 +0100
Hi Andreas,
If I understand your post correctly, you are saying that you see a performance drop of 3x when using an iterator in your inner loop as opposed to using hand-written C code to do the iterating. Unfortunately you say you haven't actually posted the code relating to the iterator... but it seems to me that this is very likely to be the source of your problems!
Your title states "dispatch_async Performance Issues", but have you actually looked into whether you see the same problem in a single-threaded case that does not use dispatch_async?
All I can suggest is that you examine the preprocessor output and even the generated assembly code with the aim of spotting any significant differences in the generated code in each case. It may well be that a function call is being generated as part of the iterator code, or something like that. Shark may help you pin down where the problem is, but you will probably need to have some level of appreciation of assembly code to be able to fully interpret the results for your optimized build. Unfortunately without the crucial part of your source code there's not a lot anyone else can do to help you in that respect...
Hope that helps a bit
Jonny_______________________________________________
Cocoa-dev mailing list (email@hidden)
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:
This email sent to email@hidden