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Mercier" , Christian =?iso-8859-1?Q?K=F6nig?= , Maxime Ripard , Albert Esteve , Dave Airlie , linux-doc@vger.kernel.org Subject: Re: [PATCH v2 2/2] cgroup/dmem: add dmem.memcg control file for double-charging to memcg Message-ID: References: <20260519-cgroup-dmem-memcg-double-charge-v2-0-db4d1407062b@redhat.com> <20260519-cgroup-dmem-memcg-double-charge-v2-2-db4d1407062b@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: X-Stat-Signature: tecrcwm1bk6kzfbn65mpcx7nnmi7bi9b X-Rspam-User: X-Rspamd-Server: rspam01 X-Rspamd-Queue-Id: 884AFC0015 X-HE-Tag: 1779466670-273248 X-HE-Meta: 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 mILV9OGR 61jqbejIr4/LVKOSjWpA45et9mqCrTz0KPzxxZcEU063ky9M6Ds9srfsgwbj3jplKiOJAFuDDbOXYmoPyFb4aySGWBft2Gwc/fCuzYM2LhSk8srcI5RcyFJy7L3scEw6gLCcjH3kp3MyStLgOfOB3EZlP3bUoUnoONsaPclH4WkmDQUoG5+XxFlCZPsACKCJrpe8MQ/TJwV/riwuNWNEZ48Qmb2cLKv7R5IBHbbjxooSXveJvwe6jPTAWvOfa+Y/kFKioMDhsVX8PNsc= Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: Hello, On Fri, May 22, 2026 at 05:26:16PM +0200, Michal Koutný wrote: > Hello Eric. > > On Tue, May 19, 2026 at 11:59:02AM -0400, Eric Chanudet wrote: > > Add a root-only cgroupfs file "dmem.memcg" that lets an administrator > > configure whether allocations in a dmem region should also be charged to > > the memory controller. > > This kinda makes sense as it is not unlike io.cost.* device > configurators. > > Just for my better understanding -- will there be a space for userspace > to switch this? (No charged dmem allocations happen before responsible > userspace runs, so that the attribute remains unlocked.) > > (I'm rather indifferent about the actual double charging/non-charging > matter.) I wonder whether this would make more sense as a mount flag? What's the use case for e.g. having different config for different devices? Wouldn't that be really confusing? Thanks. -- tejun