From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mta0.migadu.com (out-228.mta0.migadu.com [91.218.175.228]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id BD2464F0552 for ; Tue, 22 Sep 2026 15:04:26 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.228 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790089473; cv=none; b=tFHv43ynpkx39RgkvsjheN/lU3aL5XlNMn62c5qWWrHd5tesp3WMd8gxwlxmhAcKLdKUp59TLH1ks5hRnf3CiJnYdtX96rZQn3J2fC9NHxdRd45IhmHMnyNvyll1dcFLgeKhkMEKUrWTZqOoYPZvXcaSM7357oWsX6kM+UqKgeU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790089473; c=relaxed/simple; bh=JVqrVLbpqaV4yYWEGdvRO/b8euCJwpqA++3GCxL7hmE=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=jGHeTThVtXgIyxrABlvB9D7EXfGNS1APA/a4v5h0VSvFFlqxEhl+knx1q1qImEAjqO5YtbSZzEUOUhPxfS4+kVXPxsfyhx3YAi+n2AiFJOtKqay6rt70L0lLHewrb2qzgujCmR58lpVE9mpwh02EXdKu8XK5ykVP2QfppclnBuw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=VVbx5Oeq; arc=none smtp.client-ip=91.218.175.228 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="VVbx5Oeq" X-Envelope-To: linux-doc@vger.kernel.org DKIM-Signature: a=rsa-sha256; bh=JVqrVLbpqaV4yYWEGdvRO/b8euCJwpqA++3GCxL7hmE=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1790089461; v=1; x=1790694261; b=VVbx5Oeqqw2rNX+UPZrMlh5/OXQrdmaOg9k6E7EI0rnAhhG6bEBGAe4PdPUTYjOCbVIQ9fTz oeRzSmFTuUs18GPs+3dZSA992WFPrBaqMcDUU3/TFH03tkekH+y969PMiyYOy2OY54hhkTipTLL PMH2zPNoqv6jyYkbbN4Y6504= X-Envelope-To: linux-doc@vger.kernel.org Received: by smtp.migadu.com with ESMTPS id 5ccb4c3c2135a73a; Tue, 22 Sep 2026 15:04:21 +0000 X-Mizu-Trace-ID: 5ccb4c3c2135a73a X-Migadu-Flow: FLOW_OUT Date: Tue, 22 Sep 2026 23:04:14 +0800 From: Chen Yu To: Babu Moger Cc: Chen Yu , tony.luck@intel.com, reinette.chatre@intel.com, Dave.Martin@arm.com, james.morse@arm.com, bp@alien8.de, ben.horgan@arm.com, corbet@lwn.net, skhan@linuxfoundation.org, rdunlap@infradead.org, tglx@kernel.org, mingo@redhat.com, dave.hansen@linux.intel.com, hpa@zytor.com, fenghuay@nvidia.com, akpm@linux-foundation.org, rppt@kernel.org, dapeng1.mi@linux.intel.com, elver@google.com, jlayton@kernel.org, enelsonmoore@gmail.com, kuba@kernel.org, ebiggers@kernel.org, seanjc@google.com, peterz@infradead.org, chao.gao@intel.com, jmattson@google.com, naveen@kernel.org, ricardo.neri-calderon@linux.intel.com, tiala@microsoft.com, chang.seok.bae@intel.com, prathyushi.nangia@amd.com, kim.phillips@amd.com, elena.reshetova@intel.com, darwi@linutronix.de, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, x86@kernel.org Subject: Re: [PATCH v5 00/16] x86/resctrl: Add kernel-mode (e.g., PLZA) support to the resctrl subsystem Message-ID: References: <0729c208-b3d6-40cd-8316-185226838310@amd.com> Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <0729c208-b3d6-40cd-8316-185226838310@amd.com> Hi Babu, On Mon, Sep 21, 2026 at 02:27:45PM -0500, Babu Moger wrote: > > Hi Chenyu, > > On 9/20/26 22:22, Chen Yu wrote: > > Hi Babu, > > > > On Wed, Aug 26, 2026 at 02:32:14PM -0500, Babu Moger wrote: > > > > > > > > > # Create a CTRL_MON group and associate kernel-mode allocation with it. > > > # mkdir ctrl1 > > > # echo "assign_global_enable_per_cpu:ctrl=assign;mon=inherit;group=ctrl1//" \ > > > > info/kernel_mode > > > # cat info/kernel_mode > > > inherit_user > > > [assign_global_enable_per_cpu:ctrl=assign;mon=inherit;group=ctrl1//] > > > > > > # kmode_cpus and kmode_cpus_list are visible only on the associated group. > > > # ls ctrl1/kmode_cpus* > > > ctrl1/kmode_cpus ctrl1/kmode_cpus_list > > > > > > > Just curious, would the other existing files like "tasks" be exposed under ctrl1? > > If this ctrl1 is used only for "kernel space" mode, would the schemata of ctrl1 be > > shared by all tasks in the system? That is to say, it seems that there is no need to > > expose "tasks" under ctrl1. Should we hide "tasks" for the kernel group? Please > > correct me if I misunderstood. > > No, I don't think we should hide the tasks interface here. It provides the > option to use a group in a mixed mode. > > # mkdir ctrl1 > # cd ctrl1 > # echo "1,2,3" > tasks > > At this point, PIDs 1, 2, and 3 will use the schemata from ctrl1, regardless > of which CPU they are running on. They will use the same limits in both user > and kernel mode. > > # echo "assign_global_enable_per_cpu:ctrl=assign;mon=inherit;group=ctrl1//" > \ > > info/kernel_mode > > After this, all CPUs in the system will use the schemata from ctrl1 while > running in kernel mode, including when executing on behalf of PIDs 1, 2, and > 3. > > Essentially, this provides the flexibility to run in a mixed mode. > I see, a single group can be used both for regular resource control and global kernel resource control. Thanks for this explanation. thanks, Chenyu