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[82.30.61.225]) by smtp.gmail.com with ESMTPSA id r13-20020adfe68d000000b0021018642ff8sm11776063wrm.76.2022.06.27.10.56.11 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 27 Jun 2022 10:56:12 -0700 (PDT) Date: Mon, 27 Jun 2022 18:56:09 +0100 From: "Dr. David Alan Gilbert" To: James Houghton Cc: Matthew Wilcox , Mike Kravetz , Muchun Song , Peter Xu , David Hildenbrand , David Rientjes , Axel Rasmussen , Mina Almasry , Jue Wang , Manish Mishra , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [RFC PATCH 00/26] hugetlb: Introduce HugeTLB high-granularity mapping Message-ID: References: <20220624173656.2033256-1-jthoughton@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/2.2.5 (2022-05-16) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * James Houghton (jthoughton@google.com) wrote: > On Fri, Jun 24, 2022 at 11:29 AM Matthew Wilcox wrote: > > > > On Fri, Jun 24, 2022 at 05:36:30PM +0000, James Houghton wrote: > > > [1] This used to be called HugeTLB double mapping, a bad and confusing > > > name. "High-granularity mapping" is not a great name either. I am open > > > to better names. > > > > Oh good, I was grinding my teeth every time I read it ;-) > > > > How does "Fine granularity" work for you? > > "sub-page mapping" might work too. > > "Granularity", as I've come to realize, is hard to say, so I think I > prefer sub-page mapping. :) So to recap the suggestions I have so far: > > 1. Sub-page mapping > 2. Granular mapping > 3. Flexible mapping > > I'll pick one of these (or maybe some other one that works better) for > the next version of this series. Just a name; SPM might work (although may confuse those architectures which had subprotection for normal pages), and at least we can mispronounce it. In 14/26 your commit message says: 1. Faults can be passed to handle_userfault. (Userspace will want to use UFFD_FEATURE_REAL_ADDRESS to get the real address to know which region they should be call UFFDIO_CONTINUE on later.) can you explain what that new UFFD_FEATURE does? Dave -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK