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Howlett" , Vlastimil Babka , Jann Horn , Matthew Wilcox , Jan Kara Subject: Re: [RFC] madvise: best-effort deferred writeback for shared file mappings Message-ID: References: <7ebe4591-2306-4b5c-b83e-6a2e34b52bd8@kernel.org> <85aff663-2131-47da-ac04-8f0799a49b91@kernel.org> <1ce9cf3a-15dc-4815-ba29-2e22b05206fb@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Stat-Signature: qmcn5itd1mdetb6icdhing3i7trxnhj4 X-Rspam-User: X-Rspamd-Server: rspam10 X-Rspamd-Queue-Id: 4164F2000F X-HE-Tag: 1790770297-151892 X-HE-Meta: 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 +yv0FrGq cOCnjo9b19Bds+MN5L+zaD2VOST7OQpHKDWWYDyo6l/VVvQsIyrZDZmmIpR9dzdkCVcC6+rQUy/0i7r/gkxBNb/6rLu5VUjHBkYilqcoH0HSm9BD5xibwgZP2r7SthjJfskHlERnXECW1UgchJxo/J0+jsNfLiuf8wrr6hlpZNCmFlvctd8NshRFbFAxHD4AL5Pj8JPs4JjO2vsm/xPsfh696OuXIzIv9/nxCmXq0pRSYJWYOrSqYwQ8SrQ== Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Wed, Sep 30, 2026 at 01:08:33PM +0100, Lorenzo Stoakes (ARM) wrote: > I'd say in general the shape of the solution would be something > cgroups-ish, but since all of this is global stuff and the knobs are all > global I think you need to think about your design a little more. (Sorry to be clear, this is - if we accepted that this was a kernel issue that truly needed something like this - which I do not. The solution here is to use shared memory as per below.) > And in general we've seen a pattern of 'writes to MAP_SHARED, experiences > problems' before. > > And the solution is generally - use something like memfd, have a process > that does writebacks manually for you as you need. > > So I strongly suggest you do that! :) > > -- > Cheers, Lorenzo -- Cheers, Lorenzo