From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eli Cohen Subject: Re: Maximum size for memory registration (ibv_reg_mr) Date: Thu, 7 Oct 2010 13:49:04 +0200 Message-ID: <20101007114904.GB9605@mtldesk30> References: <036401cb5c35$85829220$9087b660$@edu> <037101cb5c39$b98036f0$2c80a4d0$@edu> <4CAD9572.5060507@Voltaire.com> <20101007101316.GA9605@mtldesk30> <4CADAD40.8080202@voltaire.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <4CADAD40.8080202-smomgflXvOZWk0Htik3J/w@public.gmane.org> Sender: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Or Gerlitz Cc: Jack Morgenstein , Roland Dreier , Bharath Ramesh , linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-rdma@vger.kernel.org On Thu, Oct 07, 2010 at 01:21:36PM +0200, Or Gerlitz wrote: > I would implement it for regular pages and drop a note in the > libibverbs man page that if huge pages are used (well, the huge > pages patch set isn't fully merged, maybe its about time to make > this happen...) then the actual limit is bigger, e.g follows the > proportion between the regular to the huge pages used. > What you're proposing is to change something that is not accurate in another not accurate thing. Even when you don't use huge pages, a calculation based on regular pages would be inaccurate too. That's because the allocator allocates MTTs in 2^n quantities while the registered memory need not be sized like that. Moreover, such calculation is less accurate then what we have now. -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html