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From: catalin.marinas@arm•com (Catalin Marinas)
To: linux-arm-kernel@lists•infradead.org
Subject: [RFC] ARM hugetlb support
Date: Mon, 6 Feb 2012 16:29:26 +0000	[thread overview]
Message-ID: <20120206162926.GH26538@arm.com> (raw)
In-Reply-To: <4F2B3B3E.6080807@gmail.com>

On Fri, Feb 03, 2012 at 01:41:18AM +0000, bill4carson wrote:
> On 2012?02?02? 22:38, Catalin Marinas wrote:
> > On 1 February 2012 01:56, bill4carson<bill4carson@gmail•com>  wrote:
> >> On 2012?01?31? 17:29, Catalin Marinas wrote:
> >>> It also doesn't
> >>> help much with the TLB hit rate since the micro-TLB most likely only
> >>> support 1MB sections.
> >> I am afraid I can't agree with you on this.
> >> Truly there is no specific statement about whether micro-TLB support 16MB
> >> super-sections,
> >> but main-TLB actually helps the hit rate, and main-TLB support all page size
> >> mapping.
> > The feedback over time was that 16MB didn't help much in terms of TLB
> > misses compared to 1MB but that was for standard usage. I guess the
> > hugetlbfs has specific scenarios that may benefit.
> >
> > Anyway, could you make the 2MB/16MB huge page size configurable at
> > boot time (command line option like on other architectures)?
> Actually, only X86 supports multiple page size configuration at boot 
> time, other architectures will has fixed huge page size once build.

Boot time would be just fine on ARM as well. But as we go towards single
zImage, the super-sections may not be always available so one can always
use sections as a fall-back.

> I'm not sure it's a MUST to support multiple page size at boot time,
> but I'm sure this will make marco "pte_pfn" much more complicated.

I'm not entirely sure the complicated pte_pfn is needed (see my other
comment).

-- 
Catalin

      reply	other threads:[~2012-02-06 16:29 UTC|newest]

Thread overview: 36+ 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
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 [this message]

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