From: catalin.marinas@arm•com (Catalin Marinas)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH 1/7] Add various hugetlb arm high level hooks
Date: Tue, 7 Feb 2012 12:15:11 +0000 [thread overview]
Message-ID: <20120207121511.GH3351@arm.com> (raw)
In-Reply-To: <1327910238-18704-2-git-send-email-bill4carson@gmail.com>
On Mon, Jan 30, 2012 at 07:57:12AM +0000, bill4carson at gmail.com wrote:
> +/* 2M and 16M hugepage linux ptes are stored in an array
> + *
> + * 2M hugepage
> + * ===========
> + * one linux pte caters to two HW ptes,
> + * so the maximum huge linux pte needed is 4096M/2M = 2048 entry pointers.
> + * Two 4K page is used to store these entry pointers(2048 * 4 = 8192 bytes)
> + * in a two-dimension array, huge_2m_pte[2][1024].
Actually we only need to cover TASK_SIZE so for a 2:2 split you only
need half of the above.
> + *
> + * How to find the hugepage linux pte corresponding to a specific address ?
> + * VA[31] is used as row index;
> + * VA[30:21] is used as column index;
I haven't fully reviewed the code but can we not drop this row/column
set up and just use a VA[31:21] as the index?
> + *
> + * 16M hugepage
> + * ============
> + * one linux pte caters for one HW pte,
Actually that's a bit misleading as we need 16 consecutive pmd entries
for a supersection. So one Linux pmd caters for 16 HW pmds.
> + * so maxium huge linux pte needed is 4096M/16M = 256 entry pointers,
> + * 256 * 4 = 1024 bytes spaces is allocated to store these linux pte;
> + * this is a simple one-dimension array huge_16m_pte[256].
> + *
> + * VA[31:24] is used to index this array;
Maybe we should call them Linux pmd rather than pte in the comments? It
is less confusing (I know that the generic hugetlb code calls them
ptes).
--
Catalin
next prev parent reply other threads:[~2012-02-07 12:15 UTC|newest]
Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-01-30 7:57 [RFC] ARM hugetlb support bill4carson at gmail.com
2012-01-30 7:57 ` [PATCH 1/7] Add various hugetlb arm high level hooks bill4carson at gmail.com
2012-02-06 17:07 ` Catalin Marinas
2012-02-07 2:00 ` bill4carson
2012-02-07 11:54 ` Catalin Marinas
2012-02-07 12:15 ` Catalin Marinas [this message]
2012-02-07 12:57 ` carson bill
2012-01-30 7:57 ` [PATCH 2/7] Add various hugetlb page table fix bill4carson at gmail.com
2012-01-31 9:57 ` Catalin Marinas
2012-01-31 9:58 ` Russell King - ARM Linux
2012-01-31 12:25 ` Catalin Marinas
2012-02-01 3:10 ` bill4carson
2012-02-06 16:26 ` Catalin Marinas
2012-02-07 1:42 ` bill4carson
2012-02-07 11:50 ` Catalin Marinas
2012-02-07 13:24 ` carson bill
2012-02-07 14:11 ` Catalin Marinas
2012-02-07 14:46 ` carson bill
2012-02-07 15:09 ` Catalin Marinas
2012-02-07 15:41 ` carson bill
2012-01-30 7:57 ` [PATCH 3/7] Introduce set_hugepte_ext api for huge page hardware page table setup bill4carson at gmail.com
2012-01-30 7:57 ` [PATCH 4/7] Store huge page linux pte in mm_struct bill4carson at gmail.com
2012-01-31 9:37 ` Catalin Marinas
2012-01-31 10:01 ` Russell King - ARM Linux
2012-02-01 5:45 ` bill4carson
2012-02-06 2:04 ` bill4carson
2012-02-06 10:29 ` Catalin Marinas
2012-02-06 14:40 ` carson bill
2012-01-30 7:57 ` [PATCH 5/7] Using do_page_fault for section fault handling bill4carson at gmail.com
2012-01-30 7:57 ` [PATCH 6/7] Add hugetlb Kconfig option bill4carson at gmail.com
2012-01-30 7:57 ` [PATCH 7/7] Minor compiling fix bill4carson at gmail.com
2012-01-31 9:29 ` [RFC] ARM hugetlb support Catalin Marinas
2012-02-01 1:56 ` bill4carson
2012-02-02 14:38 ` Catalin Marinas
2012-02-03 1:41 ` bill4carson
2012-02-06 16:29 ` Catalin Marinas
-- strict thread matches above, loose matches on Subject: below --
2012-02-13 9:44 [RFC-PATCH V2] " Bill Carson
2012-02-13 9:44 ` [PATCH 1/7] Add various hugetlb arm high level hooks Bill Carson
2012-02-28 17:30 ` Catalin Marinas
2012-02-29 2:34 ` bill4carson
2012-02-29 9:39 ` Catalin Marinas
2012-02-29 10:21 ` bill4carson
2012-02-29 10:23 ` Catalin Marinas
2012-02-29 10:32 ` Catalin Marinas
2012-02-29 11:28 ` bill4carson
2012-02-29 11:36 ` Catalin Marinas
2012-02-29 15:38 ` Catalin Marinas
2012-03-08 0:35 ` bill4carson
2012-03-08 9:21 ` Catalin Marinas
2012-02-29 12:31 ` Arnd Bergmann
2012-02-29 14:22 ` Catalin Marinas
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