linux-kernel - Re: [PATCH V2 5/6] x86/mm: If in_atomic(), allocate pages without sleeping

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Date:   Mon, 3 Sep 2018 10:53:26 +0200 (CEST)
From:   Thomas Gleixner <tglx@...utronix.de>
To:     Peter Zijlstra <peterz@...radead.org>
cc:     Sai Praneeth Prakhya <sai.praneeth.prakhya@...el.com>,
        linux-efi@...r.kernel.org, linux-kernel@...r.kernel.org,
        ricardo.neri@...el.com, matt@...eblueprint.co.uk,
        Lee Chun-Yi <jlee@...e.com>, Al Stone <astone@...hat.com>,
        Borislav Petkov <bp@...en8.de>, Ingo Molnar <mingo@...nel.org>,
        Andy Lutomirski <luto@...nel.org>,
        Bhupesh Sharma <bhsharma@...hat.com>,
        Ard Biesheuvel <ard.biesheuvel@...aro.org>
Subject: Re: [PATCH V2 5/6] x86/mm: If in_atomic(), allocate pages without
 sleeping

On Mon, 3 Sep 2018, Peter Zijlstra wrote:

Thanks for CC'ing me. I wonder why the world and some more is on CC, but
x86@...nel.org is NOT.

> On Sun, Sep 02, 2018 at 02:46:33AM -0700, Sai Praneeth Prakhya wrote:

> > @@ -926,7 +926,13 @@ static void unmap_pud_range(p4d_t *p4d, unsigned long start, unsigned long end)
> >  
> >  static int alloc_pte_page(pmd_t *pmd)
> >  {
> > -	pte_t *pte = (pte_t *)get_zeroed_page(GFP_KERNEL);
> > +	pte_t *pte;
> > +
> > +	if (in_atomic())
> > +		pte = (pte_t *)get_zeroed_page(GFP_ATOMIC);
> > +	else
> > +		pte = (pte_t *)get_zeroed_page(GFP_KERNEL);
> > +
> >  	if (!pte)
> >  		return -1;
> >  
> 
> This looks like tinkering to me..

Yes it is and it's not going to happen.

Thanks,

	tglx