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[71.246.228.50]) by smtp.gmail.com with ESMTPSA id af79cd13be357-8ebce6ef86dsm515161085a.30.2026.04.21.15.14.00 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 21 Apr 2026 15:14:00 -0700 (PDT) Date: Tue, 21 Apr 2026 18:13:58 -0400 From: Gregory Price To: Joanne Koong Cc: John Groves , "David Hildenbrand (Arm)" , "Darrick J. Wong" , Miklos Szeredi , Bernd Schubert , John Groves , Dan Williams , Bernd Schubert , Alison Schofield , John Groves , Jonathan Corbet , Shuah Khan , Vishal Verma , Dave Jiang , Matthew Wilcox , Jan Kara , Alexander Viro , Christian Brauner , Randy Dunlap , Jeff Layton , Amir Goldstein , Jonathan Cameron , Stefan Hajnoczi , Josef Bacik , Bagas Sanjaya , Chen Linxuan , James Morse , Fuad Tabba , Sean Christopherson , Shivank Garg , Ackerley Tng , Aravind Ramesh , Ajay Joshi , "venkataravis@micron.com" , "linux-doc@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "nvdimm@lists.linux.dev" , "linux-cxl@vger.kernel.org" , "linux-fsdevel@vger.kernel.org" , djbw@kernel.org Subject: Re: [PATCH V10 00/10] famfs: port into fuse Message-ID: References: <20260414185740.GA604658@frogsfrogsfrogs> Precedence: bulk X-Mailing-List: nvdimm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: On Tue, Apr 21, 2026 at 11:59:15AM -0700, Joanne Koong wrote: > On Tue, Apr 21, 2026 at 7:30 AM Gregory Price wrote: > > I'm not sure if this addresses Christian's concerns or not, but the > blob would reside within struct fuse_inode not struct inode. I > definitely agree with him that this should not touch or add any infra > outside fuse. > > I hadn't heard of bpf arenas until his comment. If the hashmap > overhead is too high for famfs, having a custom in-arena hash table > would be much faster I think, as it could be designed to require less > pointer chasing and avoid other overhead in the bpf hashmap > implementation, though now famfs would have to manage the data > structure and complexity itself. > I think if the fuse-inode blob is acceptable, that's highly preferable - and it wouldn't necessarily need to stay specific to bpf. If there was some generic format that folks agreed on as a baseline, that could obviously be worked into the interface. ~Gregory