G'day Matt, Interesting problems. Do you yet know how much data we are talking about? Do you have a helper app out in user land? If the amount of data required is large you could try setting up a block of pageable memory inside the kernel. I believe the IOBufferMemoryDescriptor has a pageable option. This may be a good solution for your problem. Remember thought that you will need to be careful with paging the memory in. I haven't looked at the use of pageable memory in detail yet so I can't really tell you how difficult it is to use. I do know that it is possible. Godfrey On Jul 6, , at 15:05, Matt Jaffa wrote: Hi, I am in the process of making a design descision and need to know some things before I finish up. I have a socket filter and want to cache some of the results of my querying, in the socket filter I could malloc some space and store the results in the kernel space, but is this a bad design, is it going to run out of memory, Or I could communicate to userland and store the results in some sort of cache file, but then I have to go to user space everytime my socket filter needs to check the cache? Any suggestions in my approach. Matt Jaffa _______________________________________________ darwin-kernel mailing list | darwin-kernel@lists.apple.com Help/Unsubscribe/Archives: http://www.lists.apple.com/mailman/listinfo/darwin-kernel Do not post admin requests to the list. They will be ignored.