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From: will.deacon@arm•com (Will Deacon)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH v7 0/9] ARM: VDSO
Date: Mon, 30 Jun 2014 15:40:46 +0100	[thread overview]
Message-ID: <20140630144045.GM25779@arm.com> (raw)
In-Reply-To: <1403493118-7597-1-git-send-email-nathan_lynch@mentor.com>

Hi Nathan,

On Mon, Jun 23, 2014 at 04:11:49AM +0100, Nathan Lynch wrote:
> Provide fast userspace implementations of gettimeofday and
> clock_gettime on systems that implement the generic timers extension
> defined in ARMv7.  This follows the example of arm64 in conception but
> significantly differs in some aspects of the implementation (C vs
> assembly, mainly).

[...]

This series is starting to gain traction now, so it's probably time to start
thinking about implementing this for CONFIG_COMPAT on arm64. We currently
map a fake vectors page there, but this would be much more flexible,
particularly as its written in C (and so we would magically get any new
functions added to the 32-bit version).

So, there are a couple of questions that spring to mind:

  - How difficult is it to share the vdso code with arm64 to build a compat
    vdso? (getting the Makefile to work will be hard, as we'll need an arm
    toolchain...).

  - If we use your code to build an arm64 vdso, how much slower is it than
    the handcrafted asm we currently have?

Will

  parent reply	other threads:[~2014-06-30 14:40 UTC|newest]

Thread overview: 76+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-06-23  3:11 [PATCH v7 0/9] ARM: VDSO Nathan Lynch
2014-06-23  3:11 ` [PATCH v7 1/9] clocksource: arm_arch_timer: change clocksource name if CP15 unavailable Nathan Lynch
2014-06-23  3:11 ` [PATCH v7 2/9] clocksource: arm_arch_timer: enable counter access for 32-bit ARM Nathan Lynch
2014-06-23  3:11 ` [PATCH v7 3/9] ARM: arch_timer: remove unused functions Nathan Lynch
2014-06-23  3:11 ` [PATCH v7 4/9] arm64: " Nathan Lynch
2014-06-23  3:11 ` [PATCH v7 5/9] ARM: place sigpage at a random offset above stack Nathan Lynch
2014-06-23  3:11 ` [PATCH v7 6/9] ARM: miscellaneous vdso infrastructure, preparation Nathan Lynch
2014-06-30 10:11   ` Arnd Bergmann
2014-06-30 12:27     ` Nathan Lynch
2014-06-30 13:06       ` Arnd Bergmann
2014-06-23  3:11 ` [PATCH v7 7/9] ARM: add vdso user-space code Nathan Lynch
2014-06-28  9:53   ` Russell King - ARM Linux
2014-06-28 10:03     ` Russell King - ARM Linux
2014-06-30 15:56       ` Andy Lutomirski
2014-06-28 15:19     ` Nathan Lynch
2014-06-28 15:26   ` Russell King - ARM Linux
2014-06-28 16:13     ` Nathan Lynch
2014-06-28 18:12       ` Russell King - ARM Linux
2014-06-28 19:45         ` Nathan Lynch
2014-06-28 20:11           ` Russell King - ARM Linux
2014-06-28 21:35             ` Nathan Lynch
2014-06-29  8:34               ` Russell King - ARM Linux
2014-06-29 15:48                 ` Nathan Lynch
2014-06-29 16:07                   ` Russell King - ARM Linux
2014-06-29 23:04                     ` Nathan Lynch
2014-06-30 21:33                     ` Andy Lutomirski
2014-06-30 15:59     ` Andy Lutomirski
2014-06-30 16:50       ` Nathan Lynch
2014-06-30 21:29   ` Andy Lutomirski
2014-07-01  9:00     ` Will Deacon
2014-07-01 13:34       ` Nathan Lynch
2014-07-01 14:11         ` Andy Lutomirski
2014-07-01 13:28     ` Nathan Lynch
2014-07-01 14:56       ` Andy Lutomirski
2014-06-23  3:11 ` [PATCH v7 8/9] ARM: vdso initialization, mapping, and synchronization Nathan Lynch
2014-06-30 21:37   ` Andy Lutomirski
2014-07-01  9:03     ` Will Deacon
2014-07-01 14:11       ` Nathan Lynch
2014-07-01 14:15         ` Will Deacon
2014-07-01 14:17           ` Andy Lutomirski
2014-07-01 17:27             ` Christopher Covington
2014-07-02 14:40             ` Will Deacon
2014-07-02 15:54               ` Andy Lutomirski
2014-07-02 16:18                 ` Nathan Lynch
2014-07-02 16:27                   ` Will Deacon
2014-07-02 16:47                     ` Andy Lutomirski
2014-07-02 17:24                       ` Will Deacon
2014-07-02 18:34                         ` Andy Lutomirski
2014-07-02 18:54                           ` Will Deacon
2014-07-22  0:14                             ` Andy Lutomirski
2014-07-22  8:13                               ` Will Deacon
2014-07-01 14:01     ` Nathan Lynch
2014-07-01 14:09       ` Andy Lutomirski
2014-07-01 14:14         ` Russell King - ARM Linux
2014-06-23  3:11 ` [PATCH v7 9/9] ARM: add CONFIG_VDSO Kconfig and Makefile bits Nathan Lynch
2014-06-27  8:51 ` [PATCH v7 0/9] ARM: VDSO Jan Glauber
2014-06-27  8:57   ` Russell King - ARM Linux
2014-06-27  9:41     ` Ard Biesheuvel
2014-06-27  9:46       ` Russell King - ARM Linux
2014-06-27 17:01         ` Nathan Lynch
2014-06-28  9:42           ` Russell King - ARM Linux
2014-06-28  9:55             ` Russell King - ARM Linux
2014-06-28 14:49               ` Russell King - ARM Linux
2014-06-30  7:27                 ` Arnd Bergmann
2014-06-30  7:43             ` Arnd Bergmann
2014-06-30 18:27               ` Nathan Lynch
2014-06-27 16:00   ` Nathan Lynch
2014-06-30 16:03   ` Andy Lutomirski
2014-06-30  8:12 ` Ard Biesheuvel
2014-07-01 16:34   ` Nathan Lynch
2014-07-01 20:08     ` Ard Biesheuvel
2014-07-01 22:44       ` Russell King - ARM Linux
2014-06-30 14:40 ` Will Deacon [this message]
2014-06-30 15:42   ` Nathan Lynch
2014-06-30 21:56     ` Andy Lutomirski
2014-07-01  9:04       ` Will Deacon

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