Date: Wed, 21 Jun 2017 10:03:14 +0200 (CEST)
From: Thomas Gleixner <tglx@linutronix.de>
To: Andy Lutomirski <luto@kernel.org>
cc: x86@kernel.org, linux-kernel@vger.kernel.org,
        Borislav Petkov <bp@alien8.de>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        Mel Gorman <mgorman@suse.de>,
        "linux-mm@kvack.org" <linux-mm@kvack.org>,
        Nadav Amit <nadav.amit@gmail.com>, Rik van Riel <riel@redhat.com>,
        Dave Hansen <dave.hansen@intel.com>,
        Arjan van de Ven <arjan@linux.intel.com>,
        Peter Zijlstra <peterz@infradead.org>
Subject: Re: [PATCH v3 02/11] x86/ldt: Simplify LDT switching logic
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References: <cover.1498022414.git.luto@kernel.org> <2a859ac01245f9594c58f9d0a8b2ed8a7cd2507e.1498022414.git.luto@kernel.org>
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On Tue, 20 Jun 2017, Andy Lutomirski wrote:
> When we redo lazy mode to stop flush IPIs without switching to
> init_mm, though, the current logic would become incorrect: it will
> be possible to have real_prev == next but nonetheless have a stale
> LDT descriptor.
> 
> Simplify the code to update LDTR if either the previous or the next
> mm has an LDT, i.e. effectively restore the historical logic..
> While we're at it, clean up the code by moving all the ifdeffery to
> a header where it belongs.
> 
> Acked-by: Rik van Riel <riel@redhat.com>
> Signed-off-by: Andy Lutomirski <luto@kernel.org>

Reviewed-by: Thomas Gleixner <tglx@linutronix.de>