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From:   Andy Lutomirski <luto@kernel.org>
Date:   Sat, 28 Jul 2018 19:58:44 -0700
Message-ID: <CALCETrUPvja=MNOFkN7iK7Vs=r8QbP1Avwn_gsX3UpMS5qf__Q@mail.gmail.com>
Subject: Re: [PATCH 04/10] x86,mm: use on_each_cpu_cond for TLB flushes
To:     Rik van Riel <riel@surriel.com>
Cc:     LKML <linux-kernel@vger.kernel.org>,
        kernel-team <kernel-team@fb.com>,
        Peter Zijlstra <peterz@infradead.org>,
        Andrew Lutomirski <luto@kernel.org>, X86 ML <x86@kernel.org>,
        Vitaly Kuznetsov <vkuznets@redhat.com>,
        Ingo Molnar <mingo@kernel.org>, Mike Galbraith <efault@gmx.de>,
        Dave Hansen <dave.hansen@intel.com>, will.daecon@arm.com,
        Catalin Marinas <catalin.marinas@arm.com>,
        Benjamin Herrenschmidt <benh@kernel.crashing.org>
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On Sat, Jul 28, 2018 at 2:53 PM, Rik van Riel <riel@surriel.com> wrote:
> Instead of open coding bitmap magic, use on_each_cpu_cond
> to determine which CPUs to send TLB flush IPIs to.
>
> This might be a little bit slower than examining the bitmaps,
> but it should be a lot easier to maintain in the long run.

Looks good.

i assume it's not easy to get the remove-tables case to do a single
on_each_cpu_cond() instead of two?  Currently it's doing the lazy ones
and the non-lazy ones separately.