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From: Lukasz Majewski <lukma@denx.de>
To: Andrei Vagin <avagin@gmail.com>, Dmitry Safonov <dima@arista.com>,
	Thomas Gleixner <tglx@linutronix.de>
Cc: GNU C Library <libc-alpha@sourceware.org>,
	Arnd Bergmann <arnd@arndb.de>,
	linux-kernel@vger.kernel.org
Subject: [Y2038][time namespaces] Question regarding CLOCK_REALTIME support plans in Linux time namespaces
Date: Fri, 30 Oct 2020 11:02:29 +0100	[thread overview]
Message-ID: <20201030110229.43f0773b@jawa> (raw)

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Hi Andrei, Dmitry,

I do have a question regarding the Linux time namespaces in respect of
adding support for virtualizing the CLOCK_REALTIME.

According to patch description [1] and time_namespaces documentation
[2] the CLOCK_REALTIME is not supported (for now?) to avoid complexity
and overhead in the kernel.

Is there any plan to add support for it in a near future?

Why I'm asking? 

It looks like this kernel feature (with CLOCK_REALTIME support
available) would be very helpful for testing Y2038 compliance for e.g.
glibc 32 bit ports.

To be more specific - it would be possible to modify time after time_t
32 bit overflow (i.e. Y2038 bug) on the process running Y2038
regression tests on the host system (64 bit one). By using Linux time
namespaces the system time will not be affected in any way.

Thanks in advance for your help.

Links:

[1] - https://lkml.org/lkml/2019/10/10/1329
[2] - https://www.man7.org/linux/man-pages/man7/time_namespaces.7.html


Best regards,

Lukasz Majewski

--

DENX Software Engineering GmbH,      Managing Director: Wolfgang Denk
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-59 Fax: (+49)-8142-66989-80 Email: lukma@denx.de

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             reply	other threads:[~2020-10-30 10:03 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-10-30 10:02 Lukasz Majewski [this message]
2020-10-30 13:08 ` [Y2038][time namespaces] Question regarding CLOCK_REALTIME support plans in Linux time namespaces Thomas Gleixner
2020-10-30 15:43   ` Lukasz Majewski
2020-10-30 13:58 ` Cyril Hrubis
2020-10-30 14:02   ` Zack Weinberg
2020-10-30 15:10     ` Thomas Gleixner
2020-10-30 16:58       ` Carlos O'Donell
2020-10-30 20:06         ` Thomas Gleixner
2020-10-30 22:19           ` Carlos O'Donell
2020-10-31  1:38             ` Thomas Gleixner
2020-11-03 12:43               ` Cyril Hrubis
2020-11-05 17:25               ` Carlos O'Donell
2020-11-07  0:47                 ` Thomas Gleixner
2020-11-19 18:37                   ` Carlos O'Donell
2020-11-20  0:14                     ` Thomas Gleixner
2020-11-25 17:06                       ` Petr Špaček
2020-11-25 20:37                       ` Carlos O'Donell
2020-11-26  0:17                         ` Thomas Gleixner
2020-11-26  3:05                           ` Carlos O'Donell
2020-11-26  8:21                             ` Andreas Schwab
2020-11-14 10:25 ` Pavel Machek

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