All of lore.kernel.org
 help / color / mirror / Atom feed
From: Dmitry Safonov <dima@arista.com>
To: Andrei Vagin <avagin@gmail.com>,
	linux-arm-kernel@lists.infradead.org,
	Catalin Marinas <catalin.marinas@arm.com>,
	Will Deacon <will@kernel.org>
Cc: linux-kernel@vger.kernel.org,
	Vincenzo Frascino <vincenzo.frascino@arm.com>,
	Mark Rutland <mark.rutland@arm.com>,
	Thomas Gleixner <tglx@linutronix.de>
Subject: Re: [PATCH 3/6] arm64/vdso: Add time namespace page
Date: Tue, 2 Jun 2020 20:29:17 +0100	[thread overview]
Message-ID: <fd789c85-f08b-3397-d463-501f7ee5c974@arista.com> (raw)
In-Reply-To: <20200602180259.76361-4-avagin@gmail.com>

Hi Andrei,

On 6/2/20 7:02 PM, Andrei Vagin wrote:
[..]
> --- a/arch/arm64/include/asm/vdso.h
> +++ b/arch/arm64/include/asm/vdso.h
> @@ -12,6 +12,12 @@
>   */
>  #define VDSO_LBASE	0x0
>  
> +#ifdef CONFIG_TIME_NS
> +#define __VVAR_PAGES    2
> +#else
> +#define __VVAR_PAGES    1
> +#endif
> +
>  #ifndef __ASSEMBLY__

Not an issue as-is, but:

on x86 vdso+vvar is always the same size with/without CONFIG_TIME_NAMESPACE.

Timens page isn't allocated on !CONFIG_TIME_NAMESPACE, but vma is the
same size. Which simplifies criu/vdso migration between different kernel
configs.

Not any critical, but just to note..

Thanks,
          Dima

WARNING: multiple messages have this Message-ID (diff)
From: Dmitry Safonov <dima@arista.com>
To: Andrei Vagin <avagin@gmail.com>,
	linux-arm-kernel@lists.infradead.org,
	Catalin Marinas <catalin.marinas@arm.com>,
	Will Deacon <will@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Vincenzo Frascino <vincenzo.frascino@arm.com>,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH 3/6] arm64/vdso: Add time namespace page
Date: Tue, 2 Jun 2020 20:29:17 +0100	[thread overview]
Message-ID: <fd789c85-f08b-3397-d463-501f7ee5c974@arista.com> (raw)
In-Reply-To: <20200602180259.76361-4-avagin@gmail.com>

Hi Andrei,

On 6/2/20 7:02 PM, Andrei Vagin wrote:
[..]
> --- a/arch/arm64/include/asm/vdso.h
> +++ b/arch/arm64/include/asm/vdso.h
> @@ -12,6 +12,12 @@
>   */
>  #define VDSO_LBASE	0x0
>  
> +#ifdef CONFIG_TIME_NS
> +#define __VVAR_PAGES    2
> +#else
> +#define __VVAR_PAGES    1
> +#endif
> +
>  #ifndef __ASSEMBLY__

Not an issue as-is, but:

on x86 vdso+vvar is always the same size with/without CONFIG_TIME_NAMESPACE.

Timens page isn't allocated on !CONFIG_TIME_NAMESPACE, but vma is the
same size. Which simplifies criu/vdso migration between different kernel
configs.

Not any critical, but just to note..

Thanks,
          Dima

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

  reply	other threads:[~2020-06-02 19:29 UTC|newest]

Thread overview: 34+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-06-02 18:02 [PATCH RESEND v3 0/6] arm64: add the time namespace support Andrei Vagin
2020-06-02 18:02 ` Andrei Vagin
2020-06-02 18:02 ` [PATCH 1/6] arm64/vdso: use the fault callback to map vvar pages Andrei Vagin
2020-06-02 18:02   ` Andrei Vagin
2020-06-02 18:02 ` [PATCH 2/6] arm64/vdso: Zap vvar pages when switching to a time namespace Andrei Vagin
2020-06-02 18:02   ` Andrei Vagin
2020-06-02 18:02 ` [PATCH 3/6] arm64/vdso: Add time namespace page Andrei Vagin
2020-06-02 18:02   ` Andrei Vagin
2020-06-02 19:29   ` Dmitry Safonov [this message]
2020-06-02 19:29     ` Dmitry Safonov
2020-06-02 22:04   ` kbuild test robot
2020-06-02 22:04     ` kbuild test robot
2020-06-02 22:04     ` kbuild test robot
2020-06-03  6:42   ` kbuild test robot
2020-06-03  6:42     ` kbuild test robot
2020-06-03  6:42     ` kbuild test robot
2020-06-05  7:45   ` [PATCH 3/6 v4] " Andrei Vagin
2020-06-05  7:45     ` Andrei Vagin
2020-06-02 18:02 ` [PATCH 4/6] arm64/vdso: Handle faults on timens page Andrei Vagin
2020-06-02 18:02   ` Andrei Vagin
2020-06-02 18:02 ` [PATCH 5/6] arm64/vdso: Restrict splitting VVAR VMA Andrei Vagin
2020-06-02 18:02   ` Andrei Vagin
2020-06-02 18:02 ` [PATCH 6/6] arm64: enable time namespace support Andrei Vagin
2020-06-02 18:02   ` Andrei Vagin
2020-06-02 19:31 ` [PATCH RESEND v3 0/6] arm64: add the " Dmitry Safonov
2020-06-02 19:31   ` Dmitry Safonov
2020-06-05 10:49 ` Mark Rutland
2020-06-05 10:49   ` Mark Rutland
2020-06-06  8:58   ` Andrei Vagin
2020-06-06  8:58     ` Andrei Vagin
2020-06-16  7:55 [PATCH v4 " Andrei Vagin
2020-06-16  7:55 ` [PATCH 3/6] arm64/vdso: Add time namespace page Andrei Vagin
2020-06-16  7:55   ` Andrei Vagin
2020-06-24  8:33 [PATCH v5 0/6] arm64: add the time namespace support Andrei Vagin
2020-06-24  8:33 ` [PATCH 3/6] arm64/vdso: Add time namespace page Andrei Vagin
2020-06-24  8:33   ` Andrei Vagin

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=fd789c85-f08b-3397-d463-501f7ee5c974@arista.com \
    --to=dima@arista.com \
    --cc=avagin@gmail.com \
    --cc=catalin.marinas@arm.com \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mark.rutland@arm.com \
    --cc=tglx@linutronix.de \
    --cc=vincenzo.frascino@arm.com \
    --cc=will@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.