From: Stephen Rothwell <sfr@canb.auug.org.au>
To: Arjun Roy <arjunroy.kdev@gmail.com>
Cc: davem@davemloft.net, akpm@linux-foundation.org,
linux-mm@kvack.org, arjunroy@google.com, soheil@google.com,
edumazet@google.com
Subject: Re: [PATCH mm] mm: Bring sparc pte_index() semantics inline with other platforms.
Date: Wed, 26 Feb 2020 15:22:26 +1100 [thread overview]
Message-ID: <20200226152226.3c25f5d9@canb.auug.org.au> (raw)
In-Reply-To: <20200221211707.257960-1-arjunroy.kdev@gmail.com>
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Hi Arjun,
On Fri, 21 Feb 2020 13:17:07 -0800 Arjun Roy <arjunroy.kdev@gmail.com> wrote:
>
> From: Arjun Roy <arjunroy@google.com>
>
> pte_index() on platforms other than sparc return a numerical index.
> On sparc, it returns a pte_t*. This presents an issue for
> vm_insert_pages(), which relies on pte_index() to find the offset for
> a pte within a pmd, for batched inserts.
>
> This patch:
> 1. Modifies pte_index() for sparc to return a numerical index, like
> other platforms,
> 2. Defines pte_entry() for sparc which returns a pte_t*
> (as pte_index() used to),
I wonder if you should not just make pte_offset_kernel() do what the
old pte_index() did (this seems to align with what other arches do) and
then make pte_offset_map() be defined to be pte_offset_kernel.
> -#define pte_index(dir, address) \
> - ((pte_t *) __pmd_page(*(dir)) + \
> - ((address >> PAGE_SHIFT) & (PTRS_PER_PTE - 1)))
> -#define pte_offset_kernel pte_index
> -#define pte_offset_map pte_index
> +#define pte_index(address) \
> + ((address >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
> +#define pte_entry(dir, address) \
> + ((pte_t *) __pmd_page(*(dir)) + pte_index(address))
> +#define pte_offset_kernel pte_entry
> +#define pte_offset_map pte_entry
#define pte_offset_kernel(dir, address) \
((pte_t *) __pmd_page(*(dir)) + pte_index(address))
#define pte_offset_map(dir, address) pte_offset_kernel((dir), (address))
--
Cheers,
Stephen Rothwell
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next prev parent reply other threads:[~2020-02-26 4:22 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-21 21:17 [PATCH mm] mm: Bring sparc pte_index() semantics inline with other platforms Arjun Roy
2020-02-21 21:25 ` Arjun Roy
2020-02-26 4:22 ` Stephen Rothwell [this message]
2020-02-26 23:50 ` Stephen Rothwell
2020-03-01 16:40 ` Mike Rapoport
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