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Sender: Tejun Heo <htejun@gmail.com>
Date:   Mon, 14 Nov 2022 12:38:09 -1000
From:   Tejun Heo <tj@kernel.org>
To:     Kristen Carlson Accardi <kristen@linux.intel.com>
Cc:     jarkko@kernel.org, dave.hansen@linux.kernel.org,
        linux-kernel@vger.kernel.org, linux-sgx@vger.kernel.org,
        cgroups@vger.kernel.org, Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
        Dave Hansen <dave.hansen@linux.intel.com>, x86@kernel.org,
        "H. Peter Anvin" <hpa@zytor.com>, zhiquan1.li@intel.com,
        Sean Christopherson <seanjc@google.com>
Subject: Re: [PATCH 25/26] x86/sgx: Add support for misc cgroup controller
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References: <20221111183532.3676646-1-kristen@linux.intel.com>
 <20221111183532.3676646-26-kristen@linux.intel.com>
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On Fri, Nov 11, 2022 at 10:35:30AM -0800, Kristen Carlson Accardi wrote:
> Implement support for cgroup control of SGX Enclave Page Cache (EPC)
> memory using the misc cgroup controller. EPC memory is independent
> from normal system memory, e.g. must be reserved at boot from RAM and
> cannot be converted between EPC and normal memory while the system is
> running. EPC is managed by the SGX subsystem and is not accounted by
> the memory controller.
> 
> Much like normal system memory, EPC memory can be overcommitted via
> virtual memory techniques and pages can be swapped out of the EPC to
> their backing store (normal system memory, e.g. shmem).  The SGX EPC
> subsystem is analogous to the memory subsytem and the SGX EPC controller
> is in turn analogous to the memory controller; it implements limit and
> protection models for EPC memory.
> 
> The misc controller provides a mechanism to set a hard limit of EPC
> usage via the "sgx_epc" resource in "misc.max". The total EPC memory
> available on the system is reported via the "sgx_epc" resource in
> "misc.capacity".
> 
> This patch was modified from its original version to use the misc cgroup
> controller instead of a custom controller.
> 
> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
> Signed-off-by: Kristen Carlson Accardi <kristen@linux.intel.com>
> Cc: Sean Christopherson <seanjc@google.com>

This looks fine from cgroup POV.

Thanks.

-- 
tejun