linux-kernel - Re: [PATCH 2/8] x86/mm/cpa: Move flush_tlb

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Message-ID: <65237ab4-9358-5abc-0d94-0edf9e7410cc@intel.com>
Date:   Mon, 24 Sep 2018 09:11:56 -0700
From:   Dave Hansen <dave.hansen@...el.com>
To:     Peter Zijlstra <peterz@...radead.org>
Cc:     Thomas Gleixner <tglx@...utronix.de>, linux-kernel@...r.kernel.org,
        x86@...nel.org, Bin Yang <bin.yang@...el.com>,
        Mark Gross <mark.gross@...el.com>
Subject: Re: [PATCH 2/8] x86/mm/cpa: Move flush_tlb_all()

On 09/22/2018 03:37 AM, Peter Zijlstra wrote:
> On Fri, Sep 21, 2018 at 02:34:32PM -0700, Dave Hansen wrote:
>> On 09/19/2018 01:50 AM, Peter Zijlstra wrote:
>>> @@ -1528,28 +1538,8 @@ static int __change_page_attr(struct cpa
>>>  	 * We have to split the large page:
>>>  	 */
>>>  	err = split_large_page(cpa, kpte, address);
>>> -	if (!err) {
>> ...
>>> -		flush_tlb_all();
>>> +	if (!err)
>>>  		goto repeat;
>>> -	}
>> I _think_ this is the only use of split_large_page()'s error code.  We
>> can just make it return void now, right?
> Then how does it decide to goto repeat or error out?

D'oh.  Good point.  I was misreading the diff.