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From:   Andy Lutomirski <luto@kernel.org>
Date:   Thu, 25 Apr 2019 11:50:32 -0700
Message-ID: <CALCETrVmUQ2=qddwh=CHtkaZPn1JMoN9ce=Dv5rNUvFbqjHzUw@mail.gmail.com>
Subject: Re: [PATCH v2] x86/mm/tlb: Remove flush_tlb_info from the stack
To:     Nadav Amit <namit@vmware.com>
Cc:     Peter Zijlstra <peterz@infradead.org>,
        Borislav Petkov <bp@alien8.de>,
        Andy Lutomirski <luto@kernel.org>,
        Ingo Molnar <mingo@redhat.com>,
        Thomas Gleixner <tglx@linutronix.de>, X86 ML <x86@kernel.org>,
        LKML <linux-kernel@vger.kernel.org>,
        Dave Hansen <dave.hansen@intel.com>
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On Thu, Apr 25, 2019 at 11:08 AM Nadav Amit <namit@vmware.com> wrote:
>
> Move flush_tlb_info variables off the stack. This allows to align
> flush_tlb_info to cache-line and avoid potentially unnecessary cache
> line movements. It also allows to have a fixed virtual-to-physical
> translation of the variables, which reduces TLB misses.
>
> Use per-CPU struct for flush_tlb_mm_range() and
> flush_tlb_kernel_range(). Add debug assertions to ensure there are
> no nested TLB flushes that might overwrite the per-CPU data. For
> arch_tlbbatch_flush() use a const struct.
>

I like this version of the patch.