From: Will Deacon <will.deacon@arm.com>
To: Michal Hocko <mhocko@kernel.org>
Cc: linux-mm@kvack.org, Andrew Morton <akpm@linux-foundation.org>,
LKML <linux-kernel@vger.kernel.org>,
Michal Hocko <mhocko@suse.com>,
Catalin Marinas <catalin.marinas@arm.com>,
linux-arch@vger.kernel.org
Subject: Re: [PATCH 05/19] arm64: get rid of superfluous __GFP_REPEAT
Date: Mon, 11 Apr 2016 16:49:47 +0100 [thread overview]
Message-ID: <20160411154947.GC19749@arm.com> (raw)
In-Reply-To: <1460372892-8157-6-git-send-email-mhocko@kernel.org>
On Mon, Apr 11, 2016 at 01:07:58PM +0200, Michal Hocko wrote:
> From: Michal Hocko <mhocko@suse.com>
>
> __GFP_REPEAT has a rather weak semantic but since it has been introduced
> around 2.6.12 it has been ignored for low order allocations.
>
> {pte,pmd,pud}_alloc_one{_kernel}, late_pgtable_alloc use PGALLOC_GFP for
> __get_free_page (aka order-0).
>
> pgd_alloc is slightly more complex because it allocates from pgd_cache
> if PGD_SIZE != PAGE_SIZE and PGD_SIZE depends on the configuration
> (CONFIG_ARM64_VA_BITS, PAGE_SHIFT and CONFIG_PGTABLE_LEVELS).
>
> As per
> config PGTABLE_LEVELS
> int
> default 2 if ARM64_16K_PAGES && ARM64_VA_BITS_36
> default 2 if ARM64_64K_PAGES && ARM64_VA_BITS_42
> default 3 if ARM64_64K_PAGES && ARM64_VA_BITS_48
> default 3 if ARM64_4K_PAGES && ARM64_VA_BITS_39
> default 3 if ARM64_16K_PAGES && ARM64_VA_BITS_47
> default 4 if !ARM64_64K_PAGES && ARM64_VA_BITS_48
>
> we should have the following options
>
> CONFIG_ARM64_VA_BITS:48 CONFIG_PGTABLE_LEVELS:4 PAGE_SIZE:4k size:4096 pages:1
> CONFIG_ARM64_VA_BITS:48 CONFIG_PGTABLE_LEVELS:4 PAGE_SIZE:16k size:16 pages:1
> CONFIG_ARM64_VA_BITS:48 CONFIG_PGTABLE_LEVELS:3 PAGE_SIZE:64k size:512 pages:1
> CONFIG_ARM64_VA_BITS:47 CONFIG_PGTABLE_LEVELS:3 PAGE_SIZE:16k size:16384 pages:1
> CONFIG_ARM64_VA_BITS:42 CONFIG_PGTABLE_LEVELS:2 PAGE_SIZE:64k size:65536 pages:1
> CONFIG_ARM64_VA_BITS:39 CONFIG_PGTABLE_LEVELS:3 PAGE_SIZE:4k size:4096 pages:1
> CONFIG_ARM64_VA_BITS:36 CONFIG_PGTABLE_LEVELS:2 PAGE_SIZE:16k size:16384 pages:1
>
> All of them fit into a single page (aka order-0). This means that this
> flag has never been actually useful here because it has always been used
> only for PAGE_ALLOC_COSTLY requests.
This all looks fine to me:
Acked-by: Will Deacon <will.deacon@arm.com>
Will
next prev parent reply other threads:[~2016-04-11 15:49 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <1460372892-8157-1-git-send-email-mhocko@kernel.org>
2016-04-11 11:07 ` [PATCH 01/19] tree wide: get rid of __GFP_REPEAT for order-0 allocations part I Michal Hocko
2016-04-11 11:07 ` Michal Hocko
2016-04-14 19:56 ` David Rientjes
2016-04-15 7:44 ` Michal Hocko
2016-04-15 7:44 ` Michal Hocko
2016-04-11 11:07 ` [PATCH 02/19] x86: get rid of superfluous __GFP_REPEAT Michal Hocko
2016-04-11 11:07 ` Michal Hocko
2016-04-11 11:07 ` [PATCH 03/19] x86/efi: " Michal Hocko
2016-04-11 11:07 ` Michal Hocko
2016-04-12 15:53 ` Matt Fleming
2016-04-12 15:53 ` Matt Fleming
2016-04-11 11:07 ` [PATCH 04/19] arm: " Michal Hocko
2016-04-11 11:07 ` Michal Hocko
2016-04-11 11:07 ` [PATCH 05/19] arm64: " Michal Hocko
2016-04-11 11:07 ` Michal Hocko
2016-04-11 15:49 ` Will Deacon [this message]
2016-04-11 11:07 ` [PATCH 06/19] arc: " Michal Hocko
2016-04-11 11:07 ` Michal Hocko
2016-04-11 14:23 ` Vineet Gupta
2016-04-11 11:08 ` [PATCH 07/19] mips: " Michal Hocko
2016-04-11 11:08 ` Michal Hocko
2016-04-11 11:08 ` [PATCH 08/19] nios2: " Michal Hocko
2016-04-11 11:08 ` Michal Hocko
2016-04-11 11:08 ` [PATCH 09/19] parisc: " Michal Hocko
2016-04-11 11:08 ` Michal Hocko
2016-04-11 11:08 ` [PATCH 10/19] score: " Michal Hocko
2016-04-11 11:08 ` Michal Hocko
2016-04-11 11:08 ` [PATCH 11/19] powerpc: " Michal Hocko
2016-04-11 11:08 ` Michal Hocko
2016-04-11 11:08 ` [PATCH 12/19] sparc: " Michal Hocko
2016-04-11 11:08 ` Michal Hocko
2016-04-11 11:08 ` [PATCH 13/19] s390: " Michal Hocko
2016-04-11 11:08 ` Michal Hocko
2016-04-11 11:28 ` Cornelia Huck
2016-04-11 11:28 ` Cornelia Huck
2016-04-11 12:47 ` Heiko Carstens
2016-04-11 12:47 ` Heiko Carstens
2016-04-11 11:08 ` [PATCH 14/19] sh: " Michal Hocko
2016-04-11 11:08 ` Michal Hocko
2016-04-11 11:08 ` [PATCH 15/19] tile: " Michal Hocko
2016-04-11 11:08 ` Michal Hocko
2016-04-11 11:08 ` [PATCH 16/19] unicore32: " Michal Hocko
2016-04-11 11:08 ` Michal Hocko
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