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[35.233.69.230]) by smtp.gmail.com with ESMTPSA id c20sm6618034wmb.38.2021.02.04.10.32.35 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 04 Feb 2021 10:32:35 -0800 (PST) Date: Thu, 4 Feb 2021 18:32:32 +0000 From: Quentin Perret To: Will Deacon Cc: Catalin Marinas , Marc Zyngier , James Morse , Julien Thierry , Suzuki K Poulose , Rob Herring , Frank Rowand , devicetree@vger.kernel.org, android-kvm@google.com, linux-kernel@vger.kernel.org, kernel-team@android.com, kvmarm@lists.cs.columbia.edu, linux-arm-kernel@lists.infradead.org, Fuad Tabba , Mark Rutland , David Brazdil Subject: Re: [RFC PATCH v2 12/26] KVM: arm64: Introduce a Hyp buddy page allocator Message-ID: References: <20210108121524.656872-1-qperret@google.com> <20210108121524.656872-13-qperret@google.com> <20210202181307.GA17311@willie-the-truck> <20210204143106.GA20792@willie-the-truck> <20210204182404.GB21526@willie-the-truck> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210204182404.GB21526@willie-the-truck> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thursday 04 Feb 2021 at 18:24:05 (+0000), Will Deacon wrote: > On Thu, Feb 04, 2021 at 06:19:36PM +0000, Quentin Perret wrote: > > On Thursday 04 Feb 2021 at 14:31:08 (+0000), Will Deacon wrote: > > > Just feels a bit backwards having __find_buddy() take an order parameter, > > > yet then return a page of the wrong order! __hyp_extract_page() always > > > passes the p->order as the order, > > > > Gotcha, so maybe this is just a naming problem. __find_buddy() is simply > > a helper to lookup/index the vmemmap, but it's perfectly possible that > > the 'destination' page that is being indexed has already been allocated, > > and split up multiple time (and so at a different order), etc ... And > > that is the caller's job to decide. > > > > How about __lookup_potential_buddy() ? Any suggestion? > > Hey, my job here is to waffle incoherently and hope that you find bugs in > your own code. Now you want me to _name_ something! Jeez... Hey, that's my special -- I already got Marc to make a suggestion on v1 and it's been my favorite function name so far, so why not try again? https://lore.kernel.org/kvmarm/d6a674a0e8e259161ab741d78924c756@kernel.org/ > Ok, how about __find_buddy() does what it does today but doesn't take an > order argument, whereas __find_buddy_of_order() takes the order argument > and checks the page order before returning? Sounds like a plan! Cheers, Quentin