From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jan Kara Subject: Re: [FYI] tux3: Core changes Date: Mon, 3 Aug 2015 15:07:27 +0200 Message-ID: <20150803130727.GB9657@quack.suse.cz> References: <87k2ueepd6.fsf@mail.parknet.co.jp> <20150709160528.GK2900@quack.suse.cz> <874mklaqbn.fsf@mail.parknet.co.jp> <1981a91e-30a9-43ce-9a05-14aa777e46a5@phunq.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: David Lang , Rik van Riel , Jan Kara , tux3@tux3.org, Linux Kernel Mailing List , linux-fsdevel@vger.kernel.org, OGAWA Hirofumi To: Daniel Phillips Return-path: Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org On Fri 31-07-15 17:16:45, Daniel Phillips wrote: > On Friday, July 31, 2015 5:00:43 PM PDT, Daniel Phillips wrote: > >Note: Hirofumi's email is clear, logical and speaks to the > >question. This branch of the thread is largely pointless, though > >it essentially says the same thing in non-technical terms. Perhaps > >your next response should be to Hirofumi, and perhaps it should be > >technical. > > Now, let me try to lead the way, but being specific. RDMA was raised > as a potential failure case for Tux3 page forking. But the RDMA api > does not let you use memory mmaped by Tux3 as a source or destination > of IO. Instead, it sets up its own pages and hands them out to the > RDMA app from a pool. So no issue. One down, right? Can you please tell me how you arrived to that conclusion? As far as I'm looking at the code in drivers/infiniband/ I don't see anything there preventing userspace from passing in mmapped memory... Honza -- Jan Kara SUSE Labs, CR