Subject: Re: [PATCH 5/9] x86/uv: Use the right tlbflush API
To: Peter Zijlstra <peterz@infradead.org>, <linux-kernel@vger.kernel.org>
CC: <x86@kernel.org>, Linus Torvalds <torvalds@linux-foundation.org>,
        Andy Lutomirsky <luto@kernel.org>, Dave Hansen <dave.hansen@intel.com>,
        Borislav Petkov <bpetkov@suse.de>,
        Greg KH <gregkh@linuxfoundation.org>, <keescook@google.com>,
        <hughd@google.com>, Brian Gerst <brgerst@gmail.com>,
        Josh Poimboeuf <jpoimboe@redhat.com>,
        Denys Vlasenko <dvlasenk@redhat.com>, Rik van Riel <riel@redhat.com>,
        Boris Ostrovsky <boris.ostrovsky@oracle.com>,
        Juergen Gross <jgross@suse.com>,
        David Laight <David.Laight@aculab.com>,
        Eduardo Valentin <eduval@amazon.com>, <aliguori@amazon.com>,
        Will Deacon <will.deacon@arm.com>, <daniel.gruss@iaik.tugraz.at>,
        Dave Hansen <dave.hansen@linux.intel.com>,
        Ingo Molnar <mingo@kernel.org>, <moritz.lipp@iaik.tugraz.at>,
        <linux-mm@kvack.org>, Borislav Petkov <bp@alien8.de>,
        <michael.schwarz@iaik.tugraz.at>, <richard.fellner@student.tugraz.at>,
        Mike Travis <mike.travis@hpe.com>
References: <20171205123444.990868007@infradead.org>
 <20171205123820.134563117@infradead.org>
From: Andrew Banman <abanman@hpe.com>
Message-ID: <5aed7d7f-b093-b65c-403e-46bdbcf9bc5a@hpe.com>
Date: Tue, 5 Dec 2017 15:09:48 -0600
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On 12/5/17 6:34 AM, Peter Zijlstra wrote:
> Since uv_flush_tlb_others() implements flush_tlb_others() which is
> about flushing user mappings, we should use __flush_tlb_single(),
> which too is about flushing user mappings.
> 
> Cc: Andrew Banman<abanman@hpe.com>
> Cc: Mike Travis<mike.travis@hpe.com>
> Signed-off-by: Peter Zijlstra (Intel)<peterz@infradead.org>
> ---
>   arch/x86/platform/uv/tlb_uv.c |    2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> --- a/arch/x86/platform/uv/tlb_uv.c
> +++ b/arch/x86/platform/uv/tlb_uv.c
> @@ -299,7 +299,7 @@ static void bau_process_message(struct m
>   		local_flush_tlb();
>   		stat->d_alltlb++;
>   	} else {
> -		__flush_tlb_one(msg->address);
> +		__flush_tlb_single(msg->address);
>   		stat->d_onetlb++;
>   	}
>   	stat->d_requestee++;

This looks like the right thing to do. We'll be testing it and complain later if
we find any problems, but I'm not expecting any since this patch looks to
maintain our status quo.

Best,

Andrew