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Date:   Fri, 23 Dec 2022 08:27:10 -0800
From:   Christoph Hellwig <hch@infradead.org>
To:     Mike Kravetz <mike.kravetz@oracle.com>
Cc:     linux-mm@kvack.org, linux-kernel@vger.kernel.org,
        linuxppc-dev@lists.ozlabs.org, linux-riscv@lists.infradead.org,
        linux-s390@vger.kernel.org, netdev@vger.kernel.org,
        David Hildenbrand <david@redhat.com>,
        Michal Hocko <mhocko@suse.com>, Peter Xu <peterx@redhat.com>,
        Nadav Amit <nadav.amit@gmail.com>,
        Matthew Wilcox <willy@infradead.org>,
        Vlastimil Babka <vbabka@suse.cz>,
        Rik van Riel <riel@surriel.com>,
        Will Deacon <will@kernel.org>,
        Michael Ellerman <mpe@ellerman.id.au>,
        Palmer Dabbelt <palmer@dabbelt.com>,
        Christian Borntraeger <borntraeger@linux.ibm.com>,
        Dave Hansen <dave.hansen@linux.intel.com>,
        Christian Brauner <brauner@kernel.org>,
        Eric Dumazet <edumazet@google.com>,
        Andrew Morton <akpm@linux-foundation.org>
Subject: Re: [RFC PATCH] mm: remove zap_page_range and change callers to use
 zap_vma_page_range
Message-ID: <Y6XW3hMtB7PrTSM5@infradead.org>
References: <20221216192012.13562-1-mike.kravetz@oracle.com>
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>  		unsigned long size = vma->vm_end - vma->vm_start;
>  
>  		if (vma_is_special_mapping(vma, vdso_info[VDSO_ABI_AA64].dm))
> -			zap_page_range(vma, vma->vm_start, size);
> +			zap_vma_page_range(vma, vma->vm_start, size);
>  #ifdef CONFIG_COMPAT_VDSO
>  		if (vma_is_special_mapping(vma, vdso_info[VDSO_ABI_AA32].dm))
> -			zap_page_range(vma, vma->vm_start, size);
> +			zap_vma_page_range(vma, vma->vm_start, size);
>  #endif

So for something called zap_vma_page_range I'd expect to just pass
the vma and zap all of it, which this and many other callers want
anyway.

> +++ b/arch/s390/mm/gmap.c
> @@ -722,7 +722,7 @@ void gmap_discard(struct gmap *gmap, unsigned long from, unsigned long to)
>  		if (is_vm_hugetlb_page(vma))
>  			continue;
>  		size = min(to - gaddr, PMD_SIZE - (gaddr & ~PMD_MASK));
> -		zap_page_range(vma, vmaddr, size);
> +		zap_vma_page_range(vma, vmaddr, size);

And then just call zap_page_range_single directly for those that
don't want to zap the entire vma.