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Message-ID: <6f3cc681e10877e639b882eaabf1a5e21bd2fc94.camel@kernel.org>
Subject: Re: [PATCH 02/14] x86/sgx: Add /sys/kernel/debug/x86/sgx_total_mem
From:   Jarkko Sakkinen <jarkko@kernel.org>
To:     Reinette Chatre <reinette.chatre@intel.com>,
        linux-sgx@vger.kernel.org, shuah@kernel.org
Cc:     seanjc@google.com, bp@alien8.de, dave.hansen@linux.intel.com,
        linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org
Date:   Thu, 16 Sep 2021 17:09:43 +0300
In-Reply-To: <086aa5a16faf0d9b47ba9e0ebd2213713d0e76ff.1631731214.git.reinette.chatre@intel.com>
References: <cover.1631731214.git.reinette.chatre@intel.com>
         <086aa5a16faf0d9b47ba9e0ebd2213713d0e76ff.1631731214.git.reinette.chatre@intel.com>
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On Wed, 2021-09-15 at 13:30 -0700, Reinette Chatre wrote:
> From: Jarkko Sakkinen <jarkko@kernel.org>
>=20
> Just like normal memory, SGX memory can be overcommitted.  SGX has its
> own reclaim mechanism which kicks in when physical SGX memory (Enclave
> Page Cache / EPC) is exhausted.  That reclaim mechanism is relatively
> rarely exercised and needs selftests to poke at it.
>=20
> The amount of EPC on the system is determined by the BIOS and it varies
> wildly between systems.  It can be dozens of MB on desktops, or many GB
> on servers.
>=20
> To run in a reasonable amount of time, the selftest needs to know how
> much EPC there is in the system.
>=20
> Introduce a new debugfs file to export that information.
>=20
> Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
> Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
> [reinette: Use as placeholder patch until other discussions complete]
> Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>

This could be replaced with the following two patches:

https://lore.kernel.org/linux-sgx/20210914030422.377601-1-jarkko@kernel.org=
/T/#t

I forgot to CC this to you when I sent it, sorry about that.

/Jarkko