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Date:   Tue, 10 Nov 2020 18:16:36 +0000
From:   Matthew Wilcox <willy@infradead.org>
To:     Yang Shi <shy828301@gmail.com>
Cc:     mhocko@suse.com, ziy@nvidia.com, songliubraving@fb.com,
        mgorman@suse.de, jack@suse.cz, akpm@linux-foundation.org,
        linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: [v2 PATCH 3/5] mm: migrate: skip shared exec THP for NUMA
 balancing
Message-ID: <20201110181636.GJ17076@casper.infradead.org>
References: <20201110181250.264394-1-shy828301@gmail.com>
 <20201110181250.264394-4-shy828301@gmail.com>
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On Tue, Nov 10, 2020 at 10:12:48AM -0800, Yang Shi wrote:
> @@ -2142,6 +2151,10 @@ int migrate_misplaced_transhuge_page(struct mm_struct *mm,
>  	int page_lru = page_is_file_lru(page);
>  	unsigned long start = address & HPAGE_PMD_MASK;
>  
> +	if (IS_ENABLED(CONFIG_READ_ONLY_THP_FOR_FS) &&
> +	    is_shared_exec_page(vma, page))
> +		goto out;

Why include the IS_ENABLED() check?  Once the ~50 patches I have pending
go in, shared executable THPs can exist without this option.  And can't
we have executables on tmpfs today without this option too?