Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Date:   Fri, 6 Mar 2020 20:47:02 +0200
From:   Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
To:     Sean Christopherson <sean.j.christopherson@intel.com>
Cc:     linux-kernel@vger.kernel.org, x86@kernel.org,
        linux-sgx@vger.kernel.org, akpm@linux-foundation.org,
        dave.hansen@intel.com, nhorman@redhat.com, npmccallum@redhat.com,
        haitao.huang@intel.com, andriy.shevchenko@linux.intel.com,
        tglx@linutronix.de, kai.svahn@intel.com, bp@alien8.de,
        josh@joshtriplett.org, luto@kernel.org, kai.huang@intel.com,
        rientjes@google.com, cedric.xing@intel.com, puiterwijk@redhat.com,
        linux-mm@kvack.org, Ismo Puustinen <ismo.puustinen@intel.com>,
        Mark Shanahan <mark.shanahan@intel.com>,
        Mikko Ylinen <mikko.ylinen@intel.com>,
        Derek Bombien <derek.bombien@intel.com>
Subject: Re: [PATCH v28 16/22] x86/sgx: Add a page reclaimer
Message-ID: <20200306184702.GD7472@linux.intel.com>
References: <20200303233609.713348-1-jarkko.sakkinen@linux.intel.com>
 <20200303233609.713348-17-jarkko.sakkinen@linux.intel.com>
 <20200305190354.GK11500@linux.intel.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20200305190354.GK11500@linux.intel.com>
Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On Thu, Mar 05, 2020 at 11:03:54AM -0800, Sean Christopherson wrote:
> We've also discussed taking a file descriptor to hold the backing, but
> unless I'm misreading the pagecache code, that doesn't solve the incorrect
> accounting problem because the current task, i.e. evicting task, would be
> charged.  In other words, whether the backing is kernel or user controlled
> is purely an ABI question.

Even if the file is owned by a different process the account happens
to "current"?

/Jarkko