site_archiver@lists.apple.com Delivered-To: darwin-dev@lists.apple.com Dkim-signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:message-id:from:to :in-reply-to:content-type:content-transfer-encoding:mime-version :subject:date:references:x-mailer; bh=3vajWvdStB7V6uexe1HD3KyTBOTQ1ip2NNDjePhuvg4=; b=JPP8NzZSFgojAEO9z+BrL/dHSW4X0JM6tFA+QcNLXQDUaqi0ypY/BZ9zrLsrhmq2sB evRFq8POnGAQWJfM0roeD6KQsStU3yVestUyG+Z8D5caJtM6NLEE0R6qRU4db4hgYYsP a+j4JGm/tBtWyawiKNBhk7X9DStxbUhYf2S5I= Domainkey-signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:from:to:in-reply-to:content-type :content-transfer-encoding:mime-version:subject:date:references :x-mailer; b=uRe1lwb15Mmv0EscIo9cguteqdFVmFT4SNeOdmO+nJBPSO3ChjKzA4S4OughLa3sf6 DlBqv8lQNMw3Rvb1dKH5C5DgjSx7Vgk52Y01ux/JNg3jrXZSh/7bQfvs2pnCu6P+k+/6 O16Mt4cKYhayHJeGl9B0B46oxaFamDOSPuZWE= On Nov 10, 2008, at 2:05 PM, Duane Murphy wrote: I am seeing a kIOReturnIPCError form an IOUserClient down call (i.e. from my app into the kernel) when I have a structure that is over 4K (4096) bytes in size. Is this a hard limit? Can I change this limit? I have some I/O through the user client that I would like to take a larger buffer (16K). Thanks for any tips, Eli _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-dev mailing list (Darwin-dev@lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-dev/site_archiver%40lists.appl... ...Duane Yeah, I believe the recommended path to take for passing larger amounts of data between user-space and the kernel is to use a shared buffer that is memory mapped in both the kernel and user-space. And sorry, but offhand I don't know the API to do this. I believe there is sample code for doing this, and if there isn't, I would then check Apple's open-source Darwin driver's. This email sent to site_archiver@lists.apple.com