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Date:   Tue, 17 Jul 2018 13:46:47 +0200
From:   Peter Zijlstra <peterz@infradead.org>
To:     tglx@linutronix.de, mingo@kernel.org, songliubraving@fb.com,
        torvalds@linux-foundation.org, riel@surriel.com, hpa@zytor.com,
        linux-kernel@vger.kernel.org, dave.hansen@intel.com
Cc:     linux-tip-commits@vger.kernel.org
Subject: Re: [tip:x86/mm] x86/mm/tlb: Leave lazy TLB mode at page table free
 time
Message-ID: <20180717114647.GW2476@hirez.programming.kicks-ass.net>
References: <20180716190337.26133-3-riel@surriel.com>
 <tip-2ff6ddf19c0ec40633bd14d8fe28a289816bd98d@git.kernel.org>
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On Tue, Jul 17, 2018 at 02:34:07AM -0700, tip-bot for Rik van Riel wrote:
> diff --git a/include/asm-generic/tlb.h b/include/asm-generic/tlb.h
> index 3063125197ad..e811ef7b8350 100644
> --- a/include/asm-generic/tlb.h
> +++ b/include/asm-generic/tlb.h
> @@ -303,4 +303,14 @@ static inline void tlb_remove_check_page_size_change(struct mmu_gather *tlb,
>  
>  #define tlb_migrate_finish(mm) do {} while (0)
>  
> +/*
> + * Used to flush the TLB when page tables are removed, when lazy
> + * TLB mode may cause a CPU to retain intermediate translations
> + * pointing to about-to-be-freed page table memory.
> + */
> +#ifndef HAVE_TLB_FLUSH_REMOVE_TABLES
> +#define tlb_flush_remove_tables(mm) do {} while (0)
> +#define tlb_flush_remove_tables_local(mm) do {} while (0)
> +#endif

Is there a reason these are not inline functions, which gets us type
checking and the like?