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Date: Tue, 16 Jan 2018 18:13:43 +0100
From: Joerg Roedel <joro@8bytes.org>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@kernel.org>,
        "H . Peter Anvin" <hpa@zytor.com>, x86@kernel.org,
        linux-kernel@vger.kernel.org, linux-mm@kvack.org,
        Linus Torvalds <torvalds@linux-foundation.org>,
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        Juergen Gross <jgross@suse.com>,
        Borislav Petkov <bp@alien8.de>, Jiri Kosina <jkosina@suse.cz>,
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        Brian Gerst <brgerst@gmail.com>,
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        Denys Vlasenko <dvlasenk@redhat.com>,
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        Andrea Arcangeli <aarcange@redhat.com>,
        Waiman Long <llong@redhat.com>, jroedel@suse.de
Subject: Re: [PATCH 06/16] x86/mm/ldt: Reserve high address-space range for
 the LDT
Message-ID: <20180116171343.GB28161@8bytes.org>
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Hi Peter,

On Tue, Jan 16, 2018 at 05:52:13PM +0100, Peter Zijlstra wrote:
> On Tue, Jan 16, 2018 at 05:36:49PM +0100, Joerg Roedel wrote:
> > From: Joerg Roedel <jroedel@suse.de>
> > 
> > Reserve 2MB/4MB of address space for mapping the LDT to
> > user-space.
> 
> LDT is 64k, we need 2 per CPU, and NR_CPUS <= 64 on 32bit, that gives
> 64K*2*64=8M > 2M.

Thanks, I'll fix that in the next version.


	Joerg