linux-kernel - Re: [PATCH v3 3/3] x86/mm: add TLB purge to free pmd/pte page interfaces

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Message-ID: <20180529144438.GM18595@8bytes.org>
Date:   Tue, 29 May 2018 16:44:38 +0200
From:   Joerg Roedel <joro@...tes.org>
To:     mingo@...hat.com, tglx@...utronix.de,
        Toshi Kani <toshi.kani@....com>
Cc:     mhocko@...e.com, akpm@...ux-foundation.org, tglx@...utronix.de,
        mingo@...hat.com, hpa@...or.com, cpandya@...eaurora.org,
        linux-mm@...ck.org, x86@...nel.org,
        linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
        stable@...r.kernel.org
Subject: Re: [PATCH v3 3/3] x86/mm: add TLB purge to free pmd/pte page
 interfaces

On Wed, May 16, 2018 at 05:32:07PM -0600, Toshi Kani wrote:
>  	pmd = (pmd_t *)pud_page_vaddr(*pud);
> +	pmd_sv = (pmd_t *)__get_free_page(GFP_KERNEL);
> +	if (!pmd_sv)
> +		return 0;

So your code still needs to allocate a full page where a simple
list_head on the stack would do the same job.

Ingo, Thomas, can you please just revert the original broken patch for
now until there is proper fix?

Thanks,

	Joerg