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From:   Linus Torvalds <torvalds@linux-foundation.org>
Date:   Sun, 11 Feb 2018 12:14:23 -0800
Message-ID: <CA+55aFxU4ui1tbV56x7wjzn8+OyMpNe53qoE0H-xHZiFBMFDsg@mail.gmail.com>
Subject: Re: [PATCH 00/31 v2] PTI support for x86_32
To:     Andy Lutomirski <luto@amacapital.net>
Cc:     Mark D Rustad <mrustad@gmail.com>,
        Adam Borowski <kilobyte@angband.pl>,
        Joerg Roedel <jroedel@suse.de>,
        Andy Lutomirski <luto@kernel.org>,
        Joerg Roedel <joro@8bytes.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@kernel.org>,
        "H . Peter Anvin" <hpa@zytor.com>, X86 ML <x86@kernel.org>,
        LKML <linux-kernel@vger.kernel.org>,
        Linux-MM <linux-mm@kvack.org>,
        Dave Hansen <dave.hansen@intel.com>,
        Josh Poimboeuf <jpoimboe@redhat.com>,
        Juergen Gross <jgross@suse.com>,
        Peter Zijlstra <peterz@infradead.org>,
        Borislav Petkov <bp@alien8.de>, Jiri Kosina <jkosina@suse.cz>,
        Boris Ostrovsky <boris.ostrovsky@oracle.com>,
        Brian Gerst <brgerst@gmail.com>,
        David Laight <David.Laight@aculab.com>,
        Denys Vlasenko <dvlasenk@redhat.com>,
        Eduardo Valentin <eduval@amazon.com>,
        Greg KH <gregkh@linuxfoundation.org>,
        Will Deacon <will.deacon@arm.com>,
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        Andrea Arcangeli <aarcange@redhat.com>,
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On Sun, Feb 11, 2018 at 11:42 AM, Andy Lutomirski <luto@amacapital.net> wrote:
>
> At the risk of suggesting heresy, should we consider removing x86_32 support at some point?

Maybe in five or ten years. Not in the near future, I'm afraid.

We removed support for the 80386 back at the end of 2012. At that
point it just became too painful to support at all.

In contrast, we could continue supporting 32-bit for a long time. Even
if it might be in some degraded form (ie no PTI at all, or only a slow
one).

It's not really a lot of pain for people who don't care.

                Linus